No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
Acute changes in muscle activation and leg extension performance after different running exercises in elite long distance runners
Abstract
This study investigated acute changes in muscle activation and muscular power performance after three different running exercises in elite long-distance runners. Twenty-two nationally and internationally ranked long-distance runners performed first an incremental treadmill running test until exhaustion (MR) and then 40 min continuous (TR) and intermittent (2 min run/2 min rest) (IR) running exercises at an intensity of 80 and 100% of the velocity associated with VO(2max), respectively. Muscle activation and muscular power performance tests (counter-movement jumps, CMJ, and a set of ten maximal half squats from the static starting position with an extra load of 35% of the subjects, one repetition maximum) were performed before and immediately after the runs. The average mechanical power (P) of the half squats was calculated and the root mean square electromyogram (EMGrms) from the vastus lateralis, vastus medialis, gastrocnemius and biceps femoris muscles was recorded simultaneously during the half squat performances. The results showed an acute exercise-induced increase in P (ANOVA time effect, P = 0.000) together with a reduction in EMGrms of the knee extensor muscles (ANOVA time effect, P = 0.000). However, mechanical P expressed as a relative change within the set decreased after MR. In TR the improvement in P correlated positively with the maximal running performance of the runners (P < 0.05), while in IR it correlated negatively (P < 0.05). Jumping performance was significantly enhanced after each run (P < 0.001, for all) and the improvement correlated negatively with the maximal sprinting speed and maximal jumping height of the runners (P < 0.01, for all). It is concluded that in elite long distance runners an intensive prolonged running exercise reduces the surface EMG of the knee extensor muscles, and may lead to a different coordination strategy in leg extension exercises performed into the vertical direction. After continuous type of running the power improvement correlates positively with maximal endurance running capacity, whereas after intermittent type of running it correlates negatively.
... 10,11 However, only a few studies have investigated how wholebody peak power output (PPO) changes during prolonged cycling, [12][13][14] and these have mainly been done in hot environments. 12,13 Jump-performance measures have also been obtained after prolonged exercise [15][16][17][18][19] but not after prolonged cycling. Moreover, there has been little work done on the time course of fatigue development during prolonged cycling, 2,4,8 which may help provide clues for underlying mechanisms of fatigue. ...
... The RPE remained elevated after each stoppage for muscle-function testing, being 3 RPE units higher at the start of stage 2 than at the start of stage 1. The RPE increased further during the final stage, from 16.4 ± 1.6 at 6 min to 17.8 ± 1.4 at 17 min ( Figure 2[A]), and was near maximal at exercise termination-18.7 ± 1.6 (range [16][17][18][19][20]. Heart rate climbed slowly from 82% ± 7% of maximum at 6 minutes into stage 1 to 93% ± 5% of maximum at 17 minutes on the final stage ( Figure 2[B]). ...
... 18 Hence, the decline of the reactivity coefficient at exhaustion entirely mirrored the decline of jump height. Other studies involving running have reported increases 15,19 or decreases [16][17][18] in heights of various vertical-jump tests. Ground-contact time did increase (by 7%) with 30 minutes postexercise rest ( Figure 3[B]), thus contributing to a further decline of reactivity coefficient. ...
Purpose
To quantify how whole-body power, muscle-function, and jump-performance measures change during prolonged cycling and recovery and determine whether there are relationships between the different fatigue measures.
Methods
Ten competitive or recreationally active male cyclists underwent repeated 20-min stages of prolonged cycling at 70% VO 2peak until exhaustion. Whole-body peak power output (PPO) was assessed using an all-out 30-s sprint 17 min into each cycle stage. Ratings of perceived exertion (RPE) were recorded throughout. Isometric and isokinetic muscle-function tests were made between cycle stages, over ~6 min, and during 30-min recovery. Drop-jump measures were tested at exhaustion and during recovery.
Results
PPO initially increased or was maintained in some subjects but fell to 81% of maximum at exhaustion. RPE was near maximal (18.7) at exhaustion, with the time to exhaustion related to the rate of rise of RPE. PPO first started to decline only when RPE exceeded 16 (ie, hard). Peak isometric and concentric isokinetic torque (180°/s) for the quadriceps fell to 86% and 83% of pretest at exhaustion, respectively. In contrast, the peak concentric isokinetic torque (180°/s) of the hamstrings increased by 10% before declining to 93% of maximum. Jump height fell to 92% of pretest at exhaustion and was correlated with the decline in PPO ( r = .79). Muscle-function and jump-performance measures did not recover over the 30-min postexercise rest period.
Conclusions
At exhaustion, whole-body power, muscle-function, and jump-performance measures had all fallen by 7–19%. PPO and drop-jump decrements were linearly correlated and are appropriate measures of maximal performance.
... However, after running to reach fatigue , power performance is not supposed to improve (). Contrary to expectations, previous studies indicate that not only explosive, short and intense stimuli can be used as a conditioning activity, but also sub-maximum and prolonged exercises can cause PAP for subsequent activities (Boullosa, Tuimil, Alegre, Iglesias, & Lusquiños, 2011; Vuorimaa, Virlander, Kurkilahti, Vasankari, & Häkkinen, 2006). Therefore, Hamada, Sale, and MacDougall (2000) indicated that endurance training causes, on one hand, a greater amount of phosphorylation of regulatory myosin light chains in slow fibers and, on the other hand, a greater resistance to fatigue, which would lead to prevalence of PAP in endurance runners. ...
... Chatzopoulos et al. (2007) and Jimenez-Reyes, Cuadrado, and González-Badillo (2011) observed a PAP effect on running speed using work VJ performance is greater when P force and when P power are also greater (Boullosa & Tuimil, 2009; Boullosa et al., 2011). In contrast, other authors (Vuorimaa et al., 2006) indicated that P force decreases with increasing cumulative workload, but they concluded that the loss of force is compensated for by changes in the level of coordination and other neuromuscular mechanisms that make PAP possible—such as coactivation of synergist muscles that can occur under high load conditions and increases with the duration of exercise (Gandevia, 2001). with an external load as a prior stimulus. ...
... with an external load as a prior stimulus. In the same direction, other authors (Boullosa & Tuimil, 2009; Boullosa et al., 2011; Vuorimaa et al., 2006) found PAP in VJ after different types of run. However, Parry et al. (2008) found no such potentiation in performance in a maximal effort test using a cycle ergometer exercise at very high intensity. ...
The purpose of this study is to analyze acute effect of running extended interval training(EIT) on vertical jump (VJ) and handgrip strength (HS) performance in experienced endurance athletes. In order to analyze mechanical parameters of the VJ and HS between runs, sixteen experienced male athletes performed an EIT (4x3x400m). The results show that fatigue induced by EIT does not impair handgrip strength or VJ performance. A significant improvement (p< .05) was noted for VJ due to the postactivation potentiation (PAP) phenomenon. A positive correlation (r= .619, p= .011) was found between VJ and lactate. The results suggest that experienced long-distance runners can maintain their strength levels and, consequently, work capacity, despite the induced fatigue by the field training demand. Therefore, VJ performance during EIT can be used as an indicator of muscular adaptations to training and, together, with handgrip strength, become indicators of fatigue. These indicators allow proper prescription training routines.
... Is it prefixed or individually adapted to the individual work capacity of the athlete at that intensity and that time? Regarding this, previous studies have examined the sensitivity of vertical jump performance to detect neuromuscular fatigue during continuous (Boullosa et al., 2009(Boullosa et al., , 2011Del Coso et al., 2012Rousanoglou et al., 2016) and interval running sessions (Gorostiaga et al., 2010;Morcillo et al., 2015;Vuorimaa et al., 2006) in endurance trained athletes using the countermovement jump (CMJ), which has been suggested to be the most reliable and suitable monitoring tool for this purpose in different settings (Gathercole et al., 2015). In this context, the use of the CMJ for monitoring the athletes' responses and thus deciding when the running session should be interrupted might be suggested. ...
... Rousanoglou et al., 2016) and after a half-ironman triathlon (~23%, Del Coso et al., 2012), one study did not find a reduction in CMJ height immediately after a simulated sprint-distance triathlon . Moreover, another study (Vuorimaa et al., 2006) reported an improvement (8.5%) in CMJ performance immediately after 40-min of a continuous run at an intensity of 80% of velocity associated with maximal oxygen uptake (VO2max) in elite endurance runners. Furthermore, Del Rosso et al. (2016) observed an enhancement in CMJ height during a 30-km trial in well-trained distance runners (14%). ...
... In fact, the results showed a CMJ performance enhancement after the 4 × 3 × 400 m protocol (7.89%) , and after the 10 × 400 m protocol (5.18%) (García-Pinillos et al., 2016), whereas the CMJ height remained stable during the 40 × 100 m protocol. Another previous study (Vuorimaa et al., 2006) also examined the effect of an interval running workout on CMJ height in trained endurance runners based on alternating 2 min at 100% of velocity associated with VO2max and 2 min of recovery. An increase in jumping height after each running bout was reported thus reinforcing the notion that CMJ height is not reduced during high-intensity interval running protocols at submaximal intensities. ...
Jumping performance (e.g., countermovement jump [CMJ]), as a measure of neuromuscular performance, has been suggested as an easy-to-use tool which simultaneously provides neuromuscular and metabolic information and, thereby, allows coaches to confidently monitor the status of their athletes during a workout. This hypothesis has been satisfactorily tested with sprint athletes. However, the rationale for the use of CMJ height loss as an index to monitor the workload during an endurance running session is not sufficiently evidence-based. First, it is assumed that a CMJ height loss occurs during typical interval training for endurance runners. Second, it is also assumed that a significant relationship between metabolic stress and the neuromuscular strain induced during these endurance workouts exists. These two assumptions will be questioned in this review by critically analyzing the kinetics of CMJ performance during and after running workouts, and the relationship between neuromuscular and physiological stress induced during different protocols in endurance runners. The current evidence shows that fatigue induced by common running workouts for endurance runners does not counterbalance the potentiation effect in the CMJ height. Additionally, the findings reported among different studies are consistent regarding the lack of association between CMJ height loss and physiological stress during interval sessions in endurance runners. In practical terms, the authors suggest that this marker of neuromuscular fatigue should not be used to regulate the external training load during running workouts in endurance runners. Nevertheless, the analysis of CMJ height during running workouts may serve to monitor chronic adaptations to training in endurance runners.
... Endurance training has been reported to promote a faster recovery in different physiological parameters like phosphocreatine resynthesis (21), heart rate (HR) (11,13), and neuromuscular performance (14). Recently, enhanced neuromuscular performance has been reported after fatiguing running exercises in elite endurance runners (33). These authors also observed significant relationships between the enhancement of neuromuscular parameters during the fatigued state, and physical and training characteristics like maximal aerobic speed (MAS), suggesting a relationship between training background and the postactivation potentiation (PAP) observed after running exercises (33). ...
... Recently, enhanced neuromuscular performance has been reported after fatiguing running exercises in elite endurance runners (33). These authors also observed significant relationships between the enhancement of neuromuscular parameters during the fatigued state, and physical and training characteristics like maximal aerobic speed (MAS), suggesting a relationship between training background and the postactivation potentiation (PAP) observed after running exercises (33). The same phenomenon and relationships were also found in young endurance runners after an incremental running field test (10). ...
... It is difficult to identify the physiological basis for the PAP after fatiguing exercise. Previously (33), it has been suggested that the increased height in the CMJ could be the result of an increased utilization of elastic energy. Other authors (8) found an increased elastic energy in the fatigued condition, but with an impairment of explosive force. ...
The purpose of this study was to compare jumping capacity after performing the "Université de Montréal Track Test" (UMTT) and the time limit (Tlim) at maximal aerobic speed. At the end of the competitive season, 12 well-trained male endurance runners performed the UMTT and Tlim tests on 2 different days separated by 48 hours to 7 days. Countermovement jump (CMJ) performance was assessed before and at the second and seventh minute after the 2 running protocols. An enhanced CMJ was observed at the second minute of recovery after UMTT and Tlim (p = 0.000; p = 0.015, respectively) and remained elevated only after the UMTT (p = 0.000). No significant correlations were found between jump and endurance field running performance. It is concluded that the postactivation potentiation profile after fatiguing running exercises in distance runners is protocol dependent with the mechanism yet to be determined.
... More recently, Boullosa et al., [19] showed that, after a fatiguing running test, endurance-trained runners experienced an improvement in countermovement jump (CMJ) that correlated with an increase in peak power and a lower eccentric maximum strength loss during the CMJ. This finding was consistent with that reported by others [20] and it is believed to be associated with the co-existence of post-activation potentiation (PAP) and fatigue within the muscle. PAP is defined as an acute improvement of muscular performance characteristics as a result of the contractile history [21] and it has been suggested that the PAP response after running is specific for endurance-trained athletes [19,22]. ...
... These results of a progressive decline in speed and increase in RPE throughout the trial are in line with previous studies [7,8]. On the other hand, the increase and maintenance of CMJ height along the trial appears to be related to a potentiation effect as described earlier in endurance athletes [19,20] In long distance running, it has been suggested that pacing is regulated by the sensation of fatigue, where RPE acts to evaluate the perception of exertion during exercise [4,8,40]. It would appear that athletes adjust their running speed by comparing moment-to-moment the actual with the desirable RPE for a given distance [6,8] based on an exercise template in the brain that is updated by previous experience and regulates exercise intensity. ...
... These authors suggested that a possible explanation for the enhanced performance could be a higher motor unit synchronization that might result in strength potentiation and thus delay the onset of signals related to fatigue. In this context, it has been shown that endurance athletes can exhibit concurrent fatigue and potentiation [19,20]. Moreover, as skeletal muscles can respond to homeostatic disturbances by initiating a facilitatory response to maintain force output [25] it is also possible that neural potentiation from both supraspinal and afferent input could contribute to the maintenance of force production. ...
Purpose Given the coexistence of post-activation potentiation (PAP) and fatigue within muscle, it is not known whether PAP could influence performance and pacing during distance running by moderating fatigue. The aim of this study was to assess the influence of PAP on pacing, jumping and other physiological measures during a self-paced 30 km trial. Methods Eleven male endurance-trained runners (half-marathon runners) volunteered to participate in this study. Runners participated in a multi-stage 30 km trial. Before the trial started, determination of baseline blood lactate (bLa) and countermovement jump (CMJ) height was performed. The self-paced 30 km trial consisted of 6 × 5 km splits. At the end of each 5 km split (60 s break), data on time to complete the split, CMJ height, Rating of Perceived Exertion (RPE) and blood lactate were collected while heart rate was continuously monitored. Results There was a significant decrease in speed (e.g. positive pacing strategy after the 4 th split, p<0.05) with a progressive increase in RPE throughout the trial. Compared with baseline, CMJ height was significantly (p<0.05) greater than baseline and was maintained until the end of the trial with an increase after the 5 th split, concomitant with a significant reduction in speed and an increase in RPE. Significant correlations were found between ΔCMJ and ΔSPEED (r = 0.77 to 0.87, p<0.05) at different time points as well as between RPE and speed (r =-0.61 to-0.82, p<0.05).
... Normoxic HIT sessions have also been shown to induce short-term postural control impairment (12), homeostatic perturbation (as assessed via heart rate variability [HRV] analysis [18]), and immune function depression (13,31). In contrast, short-term muscular performance, such as maximal jump height, was reported to be unaffected (44) or even improved (45) after sea-level HIT. ...
... Examining the acute impact of HIT on motor control and neuromuscular performance is therefore of interest to assess the level of strain that such training sessions are likely to put on these systems. In this study, irrespective of the environmental condition, HIT did not affect jumping ability (Table 5), whereas greater impairments in postural control and improvements in sprinting times were observed after HIT in N. The unaffected CMJ height obtained after HIT and improved sprinting performance (after N) are in line with the findings of previous studies that have reported no changes (44) or an increase (45) in jumping performance after HIT in endurance runners. The ability to sustain an adequate (or improve) muscular performance and to tolerate fatigue during HIT seems to be typical for middle distance runners and is likely related to their high percentage of slow twitch fibers (45). ...
... In this study, irrespective of the environmental condition, HIT did not affect jumping ability (Table 5), whereas greater impairments in postural control and improvements in sprinting times were observed after HIT in N. The unaffected CMJ height obtained after HIT and improved sprinting performance (after N) are in line with the findings of previous studies that have reported no changes (44) or an increase (45) in jumping performance after HIT in endurance runners. The ability to sustain an adequate (or improve) muscular performance and to tolerate fatigue during HIT seems to be typical for middle distance runners and is likely related to their high percentage of slow twitch fibers (45). Because of the reduced running speed during H, which probably decreased muscular and neural stress compared with that during N (e.g., although not measured here, lower electromyographic activity has been previously observed in hypoxia [35]), a probable postactivation potentiation effect (45) was less likely, possibly explaining, in turn, the lack of improvement in sprint times. ...
To examine the physiological strain associated with hypoxic high intensity interval training (HHIT), 8 highly trained young runners (age, 18.6 ± 5.3 years) randomly performed, 5 × 3-minute intervals in either normoxic (N, 90% of the velocity associated with VO(2max), vVO(2max)) or hypoxic (H, simulated 2,400-m altitude, 84% of νVO(2max)) conditions. Cardiorespiratory (ventilation [V(E)], oxygen consumption [V(O2)], heart rate [HR], oxygen saturation [SpO(2)]), rating of central perceived exertion (RPE(C)) responses, changes in neutrophils, erythropoietin (EPO), blood lactate ([La]) and, bicarbonate ([HCO(-)(3)]), vagal-related indices of HR variability (natural logarithm of the square root of the mean of the sum of the squares of differences [Ln rMSSD]) and maximal sprint and jump performances were compared after each session. Compared with N, H was associated with similar V(E) (Cohen's d ± 90% confidence limits, 0.0 ± 0.4, with % chances of higher/similar/lower values of 15/61/24) but at least lower VO(2) (-0.8 ± 0.4, 0/0/100), HR (-0.4 ± 0.4, 1/21/78), and SpO(2) (-1.8 ± 0.4, 0/0/100). Rating of perceived exertion was very likely higher (+0.5 ± 0.4, 92/8/0). Changes in [HCO(3)] (-0.6 ± 0.8, 5/13/83), [La] (+0.2 ± 0.4, 52/42/5), and EPO (+0.2 ± 0.4, 55/40/5) were at least possibly greater after H compared with those after N, whereas changes in neutrophils were likely lower (-0.5 ± 0.7, 4/15/81). Changes in 20-m sprint time (+0.20 ± 0.23, 49/50/1) were possibly lower after H. There was no clear difference in the changes in Ln rMSSD (+0.2 ± 1.7, 48/18/34) and jump (+0.3 ± 0.9, 60/25/15). In conclusion, although perceived as harder, HHIT is not associated with an exaggerated physiological stress in highly trained young athletes. The present results also confirm that HHIT may not be optimal for training both the cardiorespiratory and neuromuscular determinants of running performance in this population.
... On the other hand, other authors have reported improvements in countermovement jump tests aer two different field running protocols in endurance runners (Boullosa & Tuimil, 2009). Likewise, aer fatiguing running exercises, improvements in neuromuscular responses in elite resistance runners have been indicated (Vuorimaa, Virlander, Kurkilahti, Vasankari, & Häkkinen, 2006). Also, in a recent systematic review of the effect of PAP on jump performance, there is evidence regarding the effect of squat repetitions on the vertical jump performance as well as weightliing Olympic actions as clean and jerks (Picón-Martínez, Chulvi-Medrano, Cortell-Tormo & Cardozo, 2019). ...
... Based on the information above, different studies have assessed the effect of the different PAP methods such as plyometrics, sprint, squat, and jumping on the neuromuscular performance. Nevertheless, few investigations (Boullosa & Tuimil, 2009;Vuorimaa et al., 2006) have analyzed the effects of running protocols on PAP. In addition, there is no evidence of the influence some environmental conditions, such as altitude and temperature, have on PAP in runners. ...
... Also, this study shows that CMJ performance was significantly improved during post measurement. is result is in concordance with the results found in elite resistance runners who improved jump capacity and power of the lower limbs aer a running protocol of 40 minutes at 80% to determine the maximal aerobic speed in a laboratory test (Vuorimaa et al., 2006). Similarly, in twelve male athletes with an average age of 23.2 ±3.3 years, there were improvements in jump height aer two different field running protocols (Montreal Track Test vs. Tlim), especially aer the second minute of recovery (Boullosa & Tuimil, 2009); this may give a greater idea of how different endurance intensive efforts could lead to similar PAP results. ...
The purpose of this study was to explore the influence of altitude and environmental temperature on muscle mechanical and functional activation after 30' Time Trial run (30' TT). Twenty physical active males (Age= 20.4 ±3.21 years, VO2max= 47.2 ±5.2 ml/kg/min) performed a 30' TT in three different conditions of altitude and temperature: Control Condition [CC] (1137 m.a.s.l. at 26 ±1.5°C), Heat-Low Condition [HLC] (3 m.a.s.l. at 30.5 ±0.6°C), and Cool-High Condition [CHC] (2369 m.a.s.l. at 14.2 ±0.6°C). Tensiomyography (TMG), Countermovement Jump (CMJ), and Delayed Onset Muscle Soreness (DOMS) were measured pre and post running. During the 30' TT, distance, speed, heart rate (HR), rate of perceived exertion (RPE), and thermal index (WBGT) were measured. Results show a significant decrease in body weight and a significant increase in DOMS and jump height in CMJ after running in each condition. TMG responses increased maximum radial muscle displacement (Dm) and decreased muscle contraction time (Tc) both rectus and biceps femoris muscles after running. During the 30' TT, the results did not show a significant difference in RPE, HR, distance, and speed among conditions. In conclusion, altitude and temperature seem not to significantly affect the mechanical and functional responses 30' TT, despite the tendency of HLC to decrease both activation and performance.
... More recently, Boullosa et al., [19] showed that, after a fatiguing running test, endurance-trained runners experienced an improvement in countermovement jump (CMJ) that correlated with an increase in peak power and a lower eccentric maximum strength loss during the CMJ. This finding was consistent with that reported by others [20] and it is believed to be associated with the co-existence of post-activation potentiation (PAP) and fatigue within the muscle. PAP is defined as an acute improvement of muscular performance characteristics as a result of the contractile history [21] and it has been suggested that the PAP response after running is specific for endurance-trained athletes [19,22]. ...
... These results of a progressive decline in speed and increase in RPE throughout the trial are in line with previous studies [7,8]. On the other hand, the increase and maintenance of CMJ height along the trial appears to be related to a potentiation effect as described earlier in endurance athletes [19,20] In long distance running, it has been suggested that pacing is regulated by the sensation of fatigue, where RPE acts to evaluate the perception of exertion during exercise [4,8,40]. It would appear that athletes adjust their running speed by comparing moment-to-moment the actual with the desirable RPE for a given distance [6,8] based on an exercise template in the brain that is updated by previous experience and regulates exercise intensity. ...
... These authors suggested that a possible explanation for the enhanced performance could be a higher motor unit synchronization that might result in strength potentiation and thus delay the onset of signals related to fatigue. In this context, it has been shown that endurance athletes can exhibit concurrent fatigue and potentiation [19,20]. Moreover, as skeletal muscles can respond to homeostatic disturbances by initiating a facilitatory response to maintain force output [25] it is also possible that neural potentiation from both supraspinal and afferent input could contribute to the maintenance of force production. ...
Purpose
Given the co-existence of post-activation potentiation (PAP) and fatigue within muscle, it is not known whether PAP could influence performance and pacing during distance running by moderating fatigue. The aim of this study was to assess the influence of PAP on pacing, jumping and other physiological measures during a self-paced 30 km trial.
Methods
Eleven male endurance-trained runners (half-marathon runners) volunteered to participate in this study. Runners participated in a multi-stage 30 km trial. Before the trial started, determination of baseline blood lactate (bLa) and countermovement jump (CMJ) height was performed. The self-paced 30 km trial consisted of 6 × 5 km splits. At the end of each 5 km split (60 s break), data on time to complete the split, CMJ height, Rating of Perceived Exertion (RPE) and blood lactate were collected while heart rate was continuously monitored.
Results
There was a significant decrease in speed (e.g. positive pacing strategy after the 4th split, p<0.05) with a progressive increase in RPE throughout the trial. Compared with baseline, CMJ height was significantly (p<0.05) greater than baseline and was maintained until the end of the trial with an increase after the 5th split, concomitant with a significant reduction in speed and an increase in RPE. Significant correlations were found between ΔCMJ and ΔSPEED (r = 0.77 to 0.87, p<0.05) at different time points as well as between RPE and speed (r = -0.61 to -0.82, p<0.05).
Conclusion
Our results indicates that fatigue and potentiation co-exist during long lasting endurance events, and that the observed increase in jump performance towards the end of the trial could be reflecting a greater potentiation potentially perhaps counteracting the effects of fatigue and preventing further reductions in speed.
... Nevertheless, previous studies indicate that not only explosive, short, and intense stimuli can be used as a CA but also submaximum and longer or prolonged exercises can cause PAP for subsequent activities (4,5,12,22,32). Vuorimaa et al. (33) reported changes in coordination strategy in leg extension exercises performed after induced fatigue by long-distance running in elite athletes, suggesting a link between endurance training and PAP. Hamada et al. (16) indicated that endurance training causes, on one hand, a greater amount of phosphorylation of regulatory myosin light chains in slow fibers, and on the other hand, a greater resistance to fatigue, which would allow the prevalence of potentiation, and it would explain the PAP presence in endurance athletes. ...
... Hamada et al. (16) indicated that endurance training causes, on one hand, a greater amount of phosphorylation of regulatory myosin light chains in slow fibers, and on the other hand, a greater resistance to fatigue, which would allow the prevalence of potentiation, and it would explain the PAP presence in endurance athletes. Similarly, twitch potentiation has also been observed in endurance-trained athletes in evoked contractions after continuous (4,5,22) and intermittent running bouts (33). Moreover, PAP has also been reported in endurance-trained athletes in jump performance after intermittent exercises (33), continuous running exercises (12,33), and incremental protocols (4,22,32). ...
... Similarly, twitch potentiation has also been observed in endurance-trained athletes in evoked contractions after continuous (4,5,22) and intermittent running bouts (33). Moreover, PAP has also been reported in endurance-trained athletes in jump performance after intermittent exercises (33), continuous running exercises (12,33), and incremental protocols (4,22,32). ...
The purpose of this study was to analyze multiple effects of an extended interval training (EIT) protocol on countermovement jump (CMJ) and handgrip strength in endurance athletes and to determine the relationship between fatigue and potentiation. Thirty experienced sub-elite male long-distance runners (age = 28.26 +/- 8.27 years, body mass index = 22.24 +/- 2.50 kg.m(-2), and VO(2)max = 58.7 +/- 4.50 ml.kg(-1).min(-1)) participated voluntarily in this study. Subjects performed the protocol on an outdoor running track, which consisted of 12 runs of 400 m, grouped into 4 sets of 3 runs, with a passive recovery of 1 minute between runs and 3 minutes between sets (4 3 3 3 400 m). During protocol, fatigue parameters (lactate, heart rate, and rate of perceived exertion) and performance parameters (CMJ, handgrip strength, and time spent in each 400-m run) were controlled. Analysis of variance revealed a significant improvement in CMJ (p < 0.001) throughout the protocol. Cluster analysis grouped according to whether potentiation was experienced (responders group, n = 17) or not (nonresponders group, n = 13) in relation to CMJ change from rest to fatigued condition at the end of activity. Responders group significantly improved (p <= 0.05) the performance in CMJ, handgrip strength and time spent in each 400-m run. Results suggest that despite induced fatigue for EIT, trained subjects can maintain their strength and power levels and their work capacity. This fact would support the rationale that improvements in performance may be due not only to metabolic adaptations but also to specific neuromuscular adaptations. Therefore, the evaluation of power should be considered simultaneously with running performance when monitoring endurance athletes.
... power. Specifically, countermovement jump (CMJ) is an easy-to-perform, neuromuscular fatigue test for assessing athletes (Bosco et al., 1986), widely used for research and for monitoring training adaptations (García-Pinillos, Soto-Hermoso, & Latorre-Román, 2015;Gorostiaga et al., 2010;Latorre-Román, García-Pinillos, Martínez-López, & Soto-Hermoso, 2014;Vuorimaa, Vasankari, & Rusko, 2000;Vuorimaa, Virlander, Kurkilahti, Vasankari, & Häkkinen, 2006). Some previous studies have investigated the kinematics of jumping, determining the influence of the knee flexion angle-during the descent phase prior to take-off and after landing-on the outcome of the CMJ (Domire & Challis, 2007;Salles, Baltzopoulos, & Rittweger, 2011) and for the injury risk (Richards, Ajemian, Wiley, & Zernicke, 1996;Ryan, Harrison, & Hayes, 2006). ...
... The effect of fatigue induced by running exercises on jumping ability is presently not well understood. Whilst some authors have reported an acute enhancement of jump capacities (Boullosa, Tuimil, Alegre, Iglesias, & Lusquiños, 2011;García-Pinillos et al., 2015;Latorre-Román et al., 2014;Vuorimaa et al., 2006) after running protocols in runners, other authors (Boullosa & Tuimil, 2009) did not find post-activation potentiation (PAP) effects in non-runners after similar stimulus. It is well known that the contractile history of a muscle has two opposing effects on muscular force output: PAP and fatigue. ...
... The term PAP refers to the phenomenon that significantly enhances muscular twitch force after voluntary contractile activity (Mettler & Griffin, 2012). The majority of previous studies have induced PAP through the use of maximal voluntary contractions (Mettler & Griffin, 2012), but also sub-maximum and longer or prolonged exercises can cause PAP for subsequent activities (Boullosa et al., 2011;García-Pinillos et al., 2015;Latorre-Román et al., 2014;Vuorimaa et al., 2006). There is no available consensus yet, neither about the optimal acute conditioning mode protocol, nor about influence factors in that relationship such as the types of contraction involved, the muscle groups tested, the exercise duration and intensity, or the length of recovery period (Wilson et al., 2013). ...
This study aimed to determine whether kinematic data during countermovement jump (CMJ) might explain post-activation potentiation (PAP) phenomenon after an exhausting running test. Thirty-three trained endurance runners performed the Léger Test; an incremental test which consists of continuous running between two lines 20 m apart. CMJ performance was determined before (pre-test) and immediately after the protocol (post-test). Sagittal plane, video of CMJs was recorded and kinematic data were obtained throughout 2-Dimensional analysis. In addition to the duration of eccentric and concentric phases of CMJ, hip, knee and ankle angles were measured at four key points during CMJ: the lowest position of the squat, take-off, landing, and at the lowest position after landing. Additionally, heart rate was monitored, and rate of perceived exertion was recorded at post-test. Analysis of variance revealed a significant improvement in CMJ (p = 0.002) at post-test. Cluster analysis grouped according to whether PAP was experienced (responders group: RG, n = 25) or not (non-responders group: NRG, n = 8) relative to CMJ change from rest to post-test. RG significantly improved (p < 0.001) the performance in CMJ, whereas NRG remained unchanged. Kinematic data did not show significant differences between RG and NRG. Thus, the data suggest that jumping kinematic does not provide the necessary information to explain PAP phenomenon after intensive running exercises in endurance athletes.
... Among the researches that demonstrate an endurance run induces VJ enhancement, the larger difference between pre-test (30.9cm) to post-test (35.1cm) was achieved after 40 minutes of tempo run on treadmill, while running speed was adjusted to 80% VO 2 max of the subject's capacity. The 40 minutes running protocol was performed by two minutes running and two minutes of walking rest, at total running time of 20 minutes (Vuorimaa et al., 2006). In addition, Juarez et al (2011) also found CMJ difference: between pretest (41cm) to post-test (43cm) that was performed immediately after 20 minutes run at 80% of VO 2 max capacity among young soccer players. ...
... In line with VJ height enhancement, achieved by Vuorimaa et al. (2006); Boullosa & Tuimil (2009);Boullosa et al., (2011);Juarez et al., (2011);Cortis et al., (2011);Garcia et al., (2015); Garcia et al, (2016), and as shown in table 3, our study found also a significant enhancement in VJ immediately after endurance run at increasing speed until reaching 80% of VO 2 max, using YYIE1. As far as we know, this study examined, for the first time, population of volleyball players and tested them in VBJ and VAJ, that represent the natural VJ of this sport (Stanganelli et al., 2008;Sattler et al., 2012). ...
... Although there is no clear explanation for the phenomenon of exhausting or near exhausting-run induces vertical jump enhancement, the researchers attempted to explain it. According to Vuorimaa et al (2006), the explanation for the phenomenon is that after an intensive run, a different coordination strategy counteracts strength loss and even improves power in extension movements, performed vertically with both legs, like VJ. They also suggested that the increase in VJ height could be the result of an increased utilization of muscle elastic energy during the stretch-shortening cycle (SSC), 2 which is better active immediately after prolonged exhausting or near exhausting run (Bosco et al., 1982). ...
... These authors could not find any significant performance changes after both protocols. Additionally, in trained long-distance runners aged 24 years, Vuorimaa and colleagues [27] reported improved vertical jump performance (∆10-15%) following 40 min of continuous or intermittent (i.e., 2-min run/2-min rest) running at 80% and 100% of the maximum running speed achieved during a graded maximal oxygen consumption (VȮ 2max ) test, respectively. The observed discrepancy in the literature is most likely due to differences in the participants' training status [12], the type of task used to quantify fatigue [12], AE-related neuromuscular fatigue [28,29], and/or PAPE [30]. ...
... The age range within the included studies was 18-42 years. Eight studies examined AE effects on measures of muscle strength [25,34,35,[53][54][55][56][57], and another nine studies reported AE effects on proxies of muscle power [23,24,27,54,55,[58][59][60][61]. Running-based AE was examined in seven studies [23,24,27,34,54,58,59] while cycling exercises were applied in five studies [25,35,53,56,57]. ...
... Eight studies examined AE effects on measures of muscle strength [25,34,35,[53][54][55][56][57], and another nine studies reported AE effects on proxies of muscle power [23,24,27,54,55,[58][59][60][61]. Running-based AE was examined in seven studies [23,24,27,34,54,58,59] while cycling exercises were applied in five studies [25,35,53,56,57]. Three studies scrutinized the effects of sport-specific AE (i.e., small-sided soccer games) [55,60,61]. ...
Background
Concurrent training can be an effective and time-efficient method to improve both muscle strength and aerobic capacity. A major challenge with concurrent training is how to adequately combine and sequence strength exercise and aerobic exercise to avoid interference effects. This is particularly relevant for athletes.
Objective
We aimed to examine the acute effects of aerobic exercise on subsequent measures of muscle strength and power in trained male individuals.
Design
We performed a systematic review with meta-analysis.
Data Sources
Systematic literature searches in the electronic databases PubMed, Web of Science, and Google Scholar were conducted up to July 2021.
Eligibility Criteria for Selecting Studies
Studies were included that applied a within-group repeated-measures design and examined the acute effects of aerobic exercise (i.e., running, cycling exercise) on subsequent measures of lower limb muscle strength (e.g., maximal isometric force of the knee extensors) and/or proxies of lower limb muscle power (e.g., countermovement jump height) in trained individuals.
Results
Fifteen studies met the inclusion criteria. Aerobic exercise resulted in moderate declines in muscle strength (standardized mean difference [SMD] = 0.79; p = 0.003). Low-intensity aerobic exercise did not moderate effects on muscle strength (SMD = 0.65; p = 0.157) while moderate-to-high intensity aerobic exercise resulted in moderate declines in muscle strength (SMD = 0.65; p = 0.020). However, the difference between subgroups was not statistically significant ( p = 0.979). Regarding aerobic exercise duration, large declines in muscle strength were found after > 30 min (SMD = 1.02; p = 0.049) while ≤ 30 min of aerobic exercise induced moderate declines in muscle strength (SMD = 0.59; p = 0.013). The subgroup difference was not statistically significant ( p = 0.204). Cycling exercise resulted in significantly larger decrements in muscle strength (SMD = 0.79; p = 0.002) compared with running (SMD = 0.28; p = 0.035). The difference between subgroups was statistically significant ( p < 0.0001). For muscle power, aerobic exercise did not result in any statistically significant changes (SMD = 0.04; p = 0.846).
Conclusions
Aerobic exercise induced moderate declines in measures of muscle strength with no statistically significant effects on proxies of muscle power in trained male individuals. It appears that higher compared with lower intensity as well as longer compared with shorter aerobic exercise duration exacerbate acute declines in muscle strength. Our results provide evidence for acute interference effects when aerobic exercies is performed before strength exercises. These findings may help practitioners to better prescribe single training sessions, particularly if environmental and/or infrastructural reasons (e.g., availability of training facilities) do not allow the application of strength training before aerobic exercise.
... However, PAP responses have also been observed in endurance trained athletes, after maximal voluntary contractions (MVCs) (Hamada, Sale, & Macdougall, 2000). In addition, some recent studies have reported jump potentiation after different endurance running exercises in endurance athletes (Boullosa & Tuimil, 2009;Boullosa, Tuimil, Alegre, Iglesias, & Lusquinos, 2011;Vuorimaa, Virlander, Kurkilahti, Vasankari, & Hakkinen, 2006). Furthermore, Del Rosso et al. (2016) have recently shown the possible influence of jump potentiation on pacing in a 30-km trial. ...
... The remaining 40 full-text articles were analysed for inclusion and subsequently 18 articles were eliminated as they did not meet all inclusion criteria. Of the 22 articles included in the literature review, two used MVC as a conditioning activity (Hamada et al., 2000;Paasuke et al., 2007), one used submaximal intermittent contractions (Morana & Perrey, 2009), one compared different warm-up protocols (Skof & Strojnik, 2007), two assessed the effects of warm-up on subsequent simulated trial (Feros, Young, Rice, & Talpey, 2012;Silva et al., 2014), 10 studied PAP using different exercise set-ups (Boullosa et al., 2011;Boullosa & Tuimil, 2009;Garcia-Pinillos, Molina-Molina, & Latorre-Roman, 2016;Garcia-Pinillos, Soto-Hermoso, & Latorre-Roman, 2015;Latorre-Román, García-Pinillos, Martínez-López, & Soto-Hermoso, 2014;McIntyre, Mawston, & Cairns, 2012;Pageaux, Theurel, & Lepers, 2017;Skof & Strojnik, 2006a, 2006bVuorimaa et al., 2006), and eight studies looked at race simulations and competitions (Del Rosso et al., 2016;Feros et al., 2012;Millet et al., 2002;Millet, Martin, Maffiuletti, & Martin, 2003;Millet, Millet, Lattier, Maffiuletti, & Candau, 2003;Place, Lepers, Deley, & Millet, 2004;Rousanoglou et al., 2016;Silva et al., 2014). ...
... The results of previous findings in laboratory conditions with different neuromuscular evaluations (Millet et al., 2002;Millet, Martin et al., 2003;Skof & Strojnik, 2006a, 2006bVuorimaa et al., 2006) have confirmed an enhanced contractile capacity in endurance athletes after endurance exercises of different duration. Previously, Millet et al. (2002) reported a severely depressed maximal voluntary force capacity and a potentiated twitch mechanical response after an ultra-marathon. ...
While there is strong support of the usefulness of post-activation potentiation (PAP) phenomenon in power demanding sports, the role that PAP could play in endurance sports has received less attention. The aim of this review is to present evidence for a better understanding of PAP in endurance athletes; and to discuss the physiological basis and methodological aspects necessary for better practices and designing further studies. A search for relevant articles on PAP and endurance trained athletes was carried out using Medline and ISI Web of Knowledge databases. Twenty-two studies were included in the review. The current evidence suggests the possible influence of PAP for performance enhancement after appropriate conditioning activities during warm up. Evaluation of PAP responses during testing, training and competition may be also important for athletes monitoring. There are many unresolved questions about the optimum load parameters for benefiting from PAP in both training and competition; and the role that PAP may exert for optimal performance while interacting with central and peripheral factors associated with muscle fatigue. Further studies should elucidate the association between PAP responses and long-term adaptations in endurance athletes.
... In the present study, we found that the flight height of SJ, CMJ and ABA decreased in the post-race and also during the recovery period (see Table 4). These findings would reinforce the theory that the duration of exercise, the type of contractile capacity and the muscle group involved in the effort, are responsible for a decrease in muscle contractile capacity by induced peripheral fatigue [45]. The decrease in flight height of the CMJ would show how elastic muscle elements require a longer recovery time compared to the muscle contractile capacity assessed from SJ. ...
... Moreover, similar results were reported by the working group of Giandolini et al., who associated higher losses in strength production and higher muscle pain in the group that performed eccentric work in the preparation phase [9]. To the authors' knowledge, only one more study has tried to analyze the possible relationship of some parameters of ultra-trail training and its possible influence on the loss of strength [45]. Pradas et al., by separating the study sample between expert and non-expert runners (experts = 5.80 ± 2.52 and non-experts = 4.60 ± 1.26 years of experience) determined that the most expert subjects had lower losses in flying height in a post-race situation in SJ and CMJ [7]. ...
A series of case studies aimed to evaluate muscular fatigue in running a 768-km ultra-trail race in 11 days. Four non-professional athletes (four males) were enrolled. Muscle damage blood biomarkers (creatine kinase (CK), lactodeshydrogenase (LDH), aspartate transaminase (AST) and alanine aminotransferase (ALT) and lower limb strength were evaluated by using Bosco jumps test; squat jump (SJ), countermovement jump (CMJ) and Abalakov jump (ABA) were assessed before (pre), after the race (post) and for two and nine days during the recovery period (rec2 and rec9), respectively. Results showed: pre-post SJ = −28%, CMJ = −36% and ABA = −21%. Values returned to basal during rec9: SJ = −1%, CMJ = −2% or even exceeded pre-values ABA = +3%. On the contrary, muscle damage blood biomarkers values increased at post; CK = +888%, LDH = +172%, AST = +167% and ALT = +159% and the values returned gradually to baseline at rec9 except for AST = +226% and ALT = +103% which remained higher. Nonparametric bivariate Spearman's test showed strong correlations (Rs ≥ 0.8) between some jumps and muscle damage biomarkers at post (SJ-LDH Rs = 0.80, SJ-AST Rs = 0.8, ABA-LD H Rs = 0.80 and ABA-AST Rs = 0.80), at rec2 (SJ-CK Rs = 0.80 and SJ-ALT Rs = 0.80) and even during rec9 (ABA-CK). Similarly, some parameters such as accumulated elevation and training volume showed a strong correlation with LDH values after finishing the ultra-trail race. The alteration induced by completing an ultra-trail event in the muscle affects lower limb strength and may in some circumstances result in serious medical conditions including post-exer-tional rhabdomyolysis.
... Then the participants began the EIT protocol, which consisted of 12 runs of 400 m, grouped into 4 sets of 3 runs, with a passive recovery period of 1 min between runs and 3 min between sets (4 x 3 x 400 m). Interval training is used in the physical preparation of almost all endurance athletes (Gorostiaga et al., 2010;Vuorimaa et al., 2006) and is characterized by efforts lasting from 60 to 90 s with an intensity of 85-100% of maximal aerobic speed and with a high volume. ...
... A) rate of perceived exertion in a 6-20 scale; B) core temperature in Celsius degrees (ºC); C) peak heart rate, heart rate recovery and heart rate reserve, all of them in beats per minute (bpm); D) blood lactate in millilitre per kilogram per minute. The physiological variables changed in a logical way, similarly to previous studies (Gorostiaga et al., 2010;Vuorimaa et al., 2006), increasing throughout the training protocol, reaching very high intensity levels in each one of them (RPE: 18.36 ± 0.97; HRpeak: 182.20 ± 9.62 bpm; HRrec: 155.43 ± 13.07 bpm; and BLA: 13.55 ± 2.41 mmol·l -1 ). The high levels of BLA suggest that anaerobic glycolysis is extensively activated during these types of exercise, preferentially in type II muscle fibres (Green, 1978). ...
This study aimed to describe the acute impact of extended interval training (EIT) on physiological and thermoregulatory levels, as well as to determine the influence of athletic performance and age effect on the aforementioned response in endurance runners. Thirty-one experienced recreational male endurance runners voluntarily participated in this study. Subjects performed EIT on an outdoor running track, which consisted of 12 runs of 400 m. The rate of perceived exertion, physiological response through the peak and recovery heart rate, blood lactate, and thermoregulatory response through tympanic temperature, were controlled. A repeated measures analysis revealed significant differences throughout EIT in examined variables. Cluster analysis grouped according to the average performance in 400 m runs led to distinguish between athletes with a higher and lower sports level. Cluster analysis was also performed according to age, obtaining an older group and a younger group. The one-way analysis of variance between groups revealed no significant differences (p≥0.05) in the response to EIT. The results provide a detailed description of physiological and thermoregulatory responses to EIT in experienced endurance runners. This allows a better understanding of the impact of a common training stimulus on the physiological level inducing greater accuracy in the training prescription. Moreover, despite the differences in athletic performance or age, the acute physiological and thermoregulatory responses in endurance runners were similar, as long as EIT was performed at similar relative intensity.
... However, until only recently, there has been limited data quantifying the effect of HIT variable manipulation on neuromuscular function. Data on neural and muscular adjustments using force trace measures and motor nerve stimulation106107108109 following high-intensity exercise suggests that fatigue induced by HIT including either very short (\20 s) to short (B1 min) and/or non-maximal efforts (B*120 % v _ VO 2max ) tends to be predominantly peripheral in origin [106, 107, 110, 111] (i.e. alterations to muscle excitability and excitation-contraction coupling, related to intramuscular potassium concentration disturbance and accumulation of metabolic by-products including inorganic phosphate and hydrogen ions, respectively [112] ). ...
... C30 s) and all-out sprints may be more essentially related, in addition to the usually reported peripheral mechanisms, to central fatigue [113]. However, few authors, if any, have investigated the neuromuscular responses to HIT sessions using sport-and training-specific tasks, with maximal isometric voluntary contractions of the active musculature (MVC) generally chosen as the laboratory-based task for assessment of neuromuscular changes106107108109110. This is problematic, since (muscle) fatigue is task-specific [114]. ...
High-intensity interval training (HIT) is a well-known, time-efficient training method for improving cardiorespiratory and metabolic function and, in turn, physical performance in athletes. HIT involves repeated short (<45 s) to long (2-4 min) bouts of rather high-intensity exercise interspersed with recovery periods (refer to the previously published first part of this review). While athletes have used 'classical' HIT formats for nearly a century (e.g. repetitions of 30 s of exercise interspersed with 30 s of rest, or 2-4-min interval repetitions ran at high but still submaximal intensities), there is today a surge of research interest focused on examining the effects of short sprints and all-out efforts, both in the field and in the laboratory. Prescription of HIT consists of the manipulation of at least nine variables (e.g. work interval intensity and duration, relief interval intensity and duration, exercise modality, number of repetitions, number of series, between-series recovery duration and intensity); any of which has a likely effect on the acute physiological response. Manipulating HIT appropriately is important, not only with respect to the expected middle- to long-term physiological and performance adaptations, but also to maximize daily and/or weekly training periodization. Cardiopulmonary responses are typically the first variables to consider when programming HIT (refer to Part I). However, anaerobic glycolytic energy contribution and neuromuscular load should also be considered to maximize the training outcome. Contrasting HIT formats that elicit similar (and maximal) cardiorespiratory responses have been associated with distinctly different anaerobic energy contributions. The high locomotor speed/power requirements of HIT (i.e. ≥95 % of the minimal velocity/power that elicits maximal oxygen uptake [v/p[Formula: see text]O2max] to 100 % of maximal sprinting speed or power) and the accumulation of high-training volumes at high-exercise intensity (runners can cover up to 6-8 km at v[Formula: see text]O2max per session) can cause significant strain on the neuromuscular/musculoskeletal system. For athletes training twice a day, and/or in team sport players training a number of metabolic and neuromuscular systems within a weekly microcycle, this added physiological strain should be considered in light of the other physical and technical/tactical sessions, so as to avoid overload and optimize adaptation (i.e. maximize a given training stimulus and minimize musculoskeletal pain and/or injury risk). In this part of the review, the different aspects of HIT programming are discussed, from work/relief interval manipulation to HIT periodization, using different examples of training cycles from different sports, with continued reference to the cardiorespiratory adaptations outlined in Part I, as well as to anaerobic glycolytic contribution and neuromuscular/musculoskeletal load.
... The first finding of this study is the confirmation of the PAP experienced by a group of endurance athletes, from different genders and training backgrounds, after an incremental running test, which is similar to previous studies with distance runners. 8,11 This PAP was confirmed with the utilization of a force plate for jump evaluation, whereas prior studies have utilized a flight-time method that overestimates the true flight height 22 that could potentially bias results. In this regard, it is interesting to note the differences in ΔCMJ among studies for well-trained male runners with one study 8 reporting an 8.9% change, and another study 11 reporting a 12.7% change. ...
... Nevertheless, the highest capacity for developing PAP in the slighter fatigued athletes is in agreement with the previously suggested relationship between the lower level of fatigue and higher potentiation whereby both phenomena coexist and could be simultaneously modified with training intervention. 12 Another possible mechanism for this PAP may include an enhancement of elastic energy transfer 8,18 in CMJ after fatiguing tasks. These prior studies suggested an enhancement of elastic energy in the fatigued state via the difference between CMJ and squat jump performances 18 and the higher mechanical power with a reduction in EMGrms of the knee extensor muscles during half squats. ...
Countermovement jump (CMJ) and maximum running speed over a distance of 20 m were evaluated for examination of the concurrent fatigue and postactivation potentiation (PAP) in endurance athletes after an incremental field running test.
Twenty-two endurance athletes performed two attempts of CMJ on a force plate and maximum running speed test before and following the Université de Montréal Track Test (UMTT).
The results showed an improvement in CMJ height (3.6%) after UMTT that correlated with the increment in peak power (3.4%), with a concurrent peak force loss (-10.8%) that correlated with peak power enhancement. The athletes maintained their 20 m sprint performance after exhaustion. Cluster analysis reinforced the association between CMJ and peak power increments in responders with a reported correlation between peak power and sprint performance increments (r = .623; P = .041); nonresponders showed an impairment of peak force, vertical stiffness, and a higher vertical displacement of the center of mass during the countermovement that correlated with lactate concentration (r = -0.717; P = .02).
It can be suggested that PAP could counteract the peak force loss after exhaustion, allowing the enhancement of CMJ performance and the maintenance of sprint ability in endurance athletes after the UMTT. From these results, the evaluation of CMJ after incremental running tests for the assessment of muscular adaptations in endurance athletes can be recommended.
... Furthermore, a performance enhancement of CMJ height following the UMTT was also present at seven min following the completion of the protocol. Another study compared the acute effect of three different running protocols, which included treadmill running until exhaustion, a 40 min tempo run, and intermittent running (two min running, two min rest), on CMJ height, half-squat power, and muscle activation of the vastus medialis, vastus lateralis, lateral gastrocnemius, and biceps femoris during a set of 10 half-squats (Vuorimaa et al., 2006). The results indicated that each protocol resulted in statistically significant improvements in CMJ height. ...
... Garcia-Pinillos,Soto-Hermoso, & Latorre-Roman, 2015;Latorre-Román, García-Pinillos, Martínez-López, & Soto-Hermoso, 2014;Terzis et al., 2012;Vuorimaa, Virlander, Kurkilahti, Vasankari, & Häkkinen, 2006) and cycling(Lawrence, Sevene-Adams, Berning, Curtin, & Adams, 2010), in an attempt to improve similar performances. Similar to the previously discussed exercises used to induce a potentiation response, different running and cycling protocols were investigated, making their findings difficult to compare across studies.Boullosa et al. (2009) examined CMJ performance following two different running protocols, including ...
The purposes of this dissertation were to examine bilateral asymmetry as a factor of postactivation potentiation, examine and compare the acute effects of ballistic and non-ballistic concentric-only half-squats on squat jump performance, and compare the potentiation and temporal profiles of strong and weak subjects following potentiation protocols that included ballistic and non-ballistic concentric-only half-squats. The following are major findings of the dissertation. Squat jump performance may be acutely enhanced following ballistic concentric-only half-squats; however the changes in performance do not appear to be related to bilateral symmetry. Ballistic concentric-only half-squats acutely improve various squat jump performance variables at various time intervals; however the changes in performance are not related to the bilateral symmetry of the subject. Ballistic concentric-only half-squats produced superior acute potentiation effects with regard to jump height, peak power, and allometrically-scaled peak power as compared to non-ballistic concentric-only half-squats and a control protocol. Stronger subjects potentiated earlier and to a greater extent as compared to their weaker counterparts. This dissertation indicates that bilateral symmetry may not be considered as an underlying factor affecting postactivation potentiation. However, it is suggested that future research should continue to investigate the factors that are associated with postactivation potentiation. The findings of this dissertation also demonstrate the importance of how an individual performs a concentric-only squatting motion. By training with ballistic movements, a greater training stimulus may be achieved as compared to training with non-ballistic movements. While this dissertation discussed the acute potentiation differences between ballistic and non-ballistic concentric-only half-squats, longitudinal research is needed to determine if different training effects result from each training method. This dissertation also supports that notion that stronger individuals may benefit more with regard to potentiation effects. In order to optimize performance and realize the greatest potentiation effects, it is recommended that greater levels of relative strength should be sought. It is suggested that further research is needed on the longitudinal differences in the potentiation effects an individual can realize based on their strength levels.
... 4,5 To date, most of research considering HIT in endurance runners has been focused on the acute physiological and neuromuscular response. 3,[6][7][8] However, surprisingly, little attention has been given to parameters such as balance ability and stretch-shortening cycle (SSC) utilisation, which have been associated with both athletic performance and injury risk. [9][10][11][12][13] Indeed, to the best of the researchers' knowledge, no previous study has focused on determining the effect of HITs performed in a real situation-a field study-on postural control and SSC utilisation in endurance runners. ...
... It might be expected that power performance after running exercises inducing high levels of fatigue would decreased. Nevertheless, some previous studies 6,7,26,27 found post-activation potentiation (PAP)-a significant improvement in muscular power as a result of previous muscular work 28,29 -after running exercises in endurance runners. These data show that, despite high levels of fatigue, trained subjects can maintain their strength and power levels, and therefore their work capacity in terms of running pace, during HIT protocols performed above VVO2max. ...
Purpose:
This study aimed to describe the acute effects of 2 different high-intensity intermittent trainings (HIITs) on postural control, countermovement jump (CMJ), squat jump (SJ), and stretch-shortening cycle (SSC) utilisation, and to compare the changes induced by both protocols in those variables in endurance runners.
Methods:
Eighteen recreationally trained endurance runners participated in this study and were tested on 2 occasions: 10 runs of 400 m with 90 s recovery between running bouts (10 × 400 m), and 40 runs of 100 m with 30 s recovery between runs (40 × 100 m). Heart rate was monitored during both HIITs; blood lactate accumulation and rate of perceived exertion were recorded after both protocols. Vertical jump ability (CMJ and SJ) and SSC together with postural control were also controlled during both HIITs.
Results:
Repeated measures analysis revealed a significant improvement in CMJ and SJ during 10 × 400 m (p < 0.05), whilst no significant changes were observed during 40 × 100 m. Indexes related to SSC did not experience significant changes during any of the protocols. As for postural control, no significant changes were observed in the 40 × 100 m protocol, whilst significant impairments were observed during the 10 × 400 m protocol (p < 0.05).
Conclusion:
A protocol with a higher number of shorter runs (40 × 100 m) induced different changes in those neuromuscular parameters than those with fewer and longer runs (10 × 400 m). Whereas the 40 × 100 m protocol did not cause any significant changes in vertical jump ability, postural control or SSC utilisation, the 10 × 400 m protocol impaired postural control and caused improvements in vertical jumping tests.
... It has also been stated that intermittent aerobic exercise, compared to continuous exercise, causes more damage and a significant increase in circulating testosterone levels after exercise in endurance-trained men because the muscle contractile filaments are subjected to greater stress and strain [3]. Vuorimaa et al. [13] demonstrated that in runners (middle-vs. long-distance) the muscle performance and muscle activation responses to intermittent and continuous type of running are related to their training background. ...
... It is noteworthy that the testosterone response to intermittent exercise was greater in middle-distance runners than in marathon runners. They stated that training background can have an impact on the response of testosterone to intermittent and continuous exercise [14] because the muscle performance and muscle activation responses to intermittent and continuous type of running are different and related to runners training background (fast intermittent training vs. continuous types of running training) [13]. Hackney et al. [3] examined free testosterone changes in 15 endurance-trained males after continuous and intermittent exercise. ...
Purpose
Different types of physical activity can induce different hormonal and physiological responses. In this study, we examined the testosterone, cortisol, creatine kinase (CK) and lactate dehydrogenase (LDH) response to acute intermittent (IE) and continuous (CE) aerobic exercise in sedentary men.
Methods
In this single-blinded randomised crossover study, eleven sedentary healthy males completed protocols (CE and IE) on two different days separated by a 1-week washout period. CE comprised 40 min of running on a treadmill at 60% of reserve heart rate. IE consisted of 40 min of running on a treadmill with intensity alternating between 50% (2 min) and 80% (1 min) of reserve heart rate. Blood samples were taken before and immediately after each exercise session.
Results
Serum testosterone concentrations increased significantly after IE (+8.0%, P = 0.021) and decreased non-significantly after CE (−5.8%, P = 0.409). The IE response was greater than the CE response (P = 0.01). Cortisol concentration decreased in both IE and CE exercise (P = 0.001 and P = 0.016, respectively), by −33.6 and −34.6%, respectively. The testosterone to cortisol ratio increased significantly after both forms of exercise (IE: P = 0.003; CE: P = 0.041). CK concentrations significantly increased from PRE to POST (IE: +20.6%, P = 0.001; CE: +26.5%, P = 0.046). Despite the increase in concentrations of LDH, the changes were not significant (F(3, 30) = 1.01, P = 0.402; IE: +11.4% and CE: +23.1%).
Conclusions
In summary, it seems that intermittent exercise can be more useful in the development of body anabolic processes in sedentary men due to pronounced increases in testosterone.
... The effect of fatigue induced by running exercises on jumping ability is not well understood. While some authors have reported an acute enhancement of jumping ability (Boullosa et al., 2011;García-Pinillos et al., 2015;Latorre-Román et al., 2014;Vuorimaa et al., 2006) after running protocols in runners, others (Boullosa and Tuimil, 2009) have not found post-activation potentiation (PAP) effects in non-runners after a similar stimulus. ...
... There is also a lack of information on the mechanism responsible for the PAP phenomenon induced by running exercises in endurance runners. Among the studies that found PAP after submaximal exercise, Vuorimaa et al. (2006) showed that 40 min of running at a speed corresponding to 80% VO2max produced significant improvement in power performance of elite longdistance runners. However, the authors gauged intensity by maximum oxygen uptake, without taking into account the individual lactate threshold of the subjects. ...
To determine the relationship between fatigue and post-activation potentiation, we examined the effects of sub-maximal continuous running on neuromuscular function tests, as well as on the squat jump and counter movement jump in endurance athletes. The height of the squat jump and counter movement jump and the estimate of the fast twitch fiber recruiting capabilities were assessed in seven male middle distance runners before and after 40 min of continuous running at an intensity corresponding to the individual lactate threshold. The same test was then repeated after three weeks of specific aerobic training. Since the three variables were strongly correlated, only the estimate of the fast twitch fiber was considered for the results. The subjects showed a significant improvement in the fast twitch fiber recruitment percentage after the 40 min run. Our data show that submaximal physical exercise determined a change in fast twitch muscle fiber recruitment patterns observed when subjects performed vertical jumps; however, this recruitment capacity was proportional to the subjects’ individual fast twitch muscle fiber profiles measured before the 40 min run. The results of the jump tests did not change significantly after the three-week training period. These results suggest that pre-fatigue methods, through sub-maximal exercises, could be used to take advantage of explosive capacity in middle-distance runners.
... Nevertheless, none of these studies included a comparison with CR, so the effects of CR at a neuromuscular level remain unknown. Contradictory results can be found in recent literature; although some previous works have reported 8%-16% reductions in jumping test performance (drop jump and repeated jump tests) after a marathon 50 and a negative influence of intensive aerobic running (6 km at velocity related to lactate threshold) on some muscle contractile characteristics (i.e., an impaired excitation-contraction coupling), a previous work by Vuorimaa et al. 51 investigated acute changes in muscle activation and muscular power performance after 40 min of CR at an intensity of 80% VVO2max in elite long-distance runners and showed an enhanced jumping performance postexercise. Note: 0 = item was not satisfied; 1 = item was satisfied. ...
Objective: This systematic review aimed to critically analyze the literature to determine how high-intensity intermittent training (HIIT) affects recreational endurance runners in the short- and long-term.
Methods: Electronic databases were searched for literature dating from January 2000 to October 2015. The search was conducted using the key words ?high-intensity intermittent training? or ?high-intensity interval exercise? or ?interval running? or ?sprint interval training? and ?endurance runners? or ?long distance runners?. A systematic approach was used to evaluate the 783 articles identified for initial review. Studies were included if they investigated HIIT in recreational endurance runners. The methodological quality of the studies was evaluated using the Physiotherapy Evidence Database (PEDro) scale (for intervention studies) and the modified Downs and Black Quality Index (for cross-sectional studies).
Results: Twenty-three studies met the inclusionary criteria for review. The results are presented in 2 parts: cross-sectional (n?=?15) and intervention studies (n?=?8). In the 15 cross-sectional studies selected, endurance runners performed at least 1 HIIT protocol, and the acute impact on physiological, neuromuscular, metabolic and/or biomechanical variables was assessed. Intervention studies lasted a minimum of 4 weeks, with 10 weeks being the longest intervention period, and included 2 to 4 HIIT sessions per week. Most of these studies combined HIIT sessions with continuous run (CR) sessions; 2 studies' subjects performed HIIT exclusively.
Conclusion: HIIT-based running plans (2 to 3 HIIT sessions per week, combining HIIT and CR runs) show athletic performance improvements in endurance runners by improving maximal oxygen uptake and running economy along with muscular and metabolic adaptations. To maximize the adaptations to training, both HIIT and CR must be part of training programs for endurance runners.
... In fact, this is a specific adaptive response of trained individuals, as the same protocol did not induce PAP in a group of physical education students when they were compared with well-trained runners [8]. Furthermore, the study by Vuorimaa et al. [9] clearly showed that greater jump potentiation was observed after tempo running for 40 min at 80 % of vVO 2max (14.5 %), when compared with 2 min intervals at vVO 2max (10.7 %) and after a maximal incremental test (8.9 %). This suggests that lower intensities than vVO 2max would be more appropriate for optimal neuromuscular loading when looking for PAP after running exercises. ...
... In this respect, it is still to be determined if more specific stimuli for endurance athletes (e.g. prolonged submaximal exercise) [51] would elicit greater PAPE than highintensity brief efforts [6,32,50] or a combination of both stimuli [41]. Importantly, this may be related to the physiological profile of the athletes (e.g. ...
In this review, we will present and critically discuss how different conditioning exercises can be implemented in training, testing, and competition for the enhancement of performances in different sports, via post-activation performance enhancement and other delayed potentiation responses. The potentiation approaches described here include warming up, testing and monitoring, re-warm-up and priming strategies, and complex training. The post-activation performance enhancement responses can be best described following the new taxonomy, which allows the identification of the best strategies in every specific sport setting. This requires identifying the post-activation performance enhancement factors, which are the conditioning activity, the verification test, the population of athletes; and potential moderators (i.e. exercise type and loading, timing; recovery interval, target exercise, performance parameter; training background, age, and sex). The inherent limitations to these approaches, including the gaps in literature requiring further studies, may be overcome in practice by using individualized approaches.
... Data were registered by a linear encoder (Ergotest, Langesud, Norway). This device has been widely used to evaluate dynamic muscle work and has achieved good reliability scores in previous reports (Gonzalo-Skok et al., 2013;Vuorimaa et al., 2006). In pilot studies, the Loadopt has also shown good reliability (ICC = 0.96 and CV (%) = 3.70%). ...
The aim of this study was to analyse the acute effects of a concentric exercise and two different eccentric overload exercises (EOEs) on blood markers of muscle damage (i.e. creatine kinase [CK], lactate dehydrogenase [LDH], myoglobin [Myo], and malondialdehyde [MDA]) and muscle contractile properties. Ten healthy, young (27 ± 1.5 years, 179 ± 6 cm, 78.7 ± 10.8 kg), physically active men (3.5 ± 1.9 h·w-1) randomly performed three training sessions using the following protocols: a half-squat (HS) as a concentric exercise, and exercises using Versapulley (VP) or YoYo isoinertial technology (YIT) as EOEs (4 x 7 repetitions with a 2 min rest interval between sets). Blood samples and tensiomyography measurements were obtained after each training session. Repeated measures analysis of variance (ANOVA) followed by the Tukey test was used to detect differences between the four time points of each variable. The standardized difference or effect size (ES, 90% confidence limit) in the selected variables was calculated using the basal SD. After all exercises, a greater activity of CK, LDH, and concentration of Myo, and MDA were found compared to baseline values (p < 0.05). A substantially greater activity of CK, LDH, and Myo concentration, but not MDA, were found after EOEs when compared to the HS protocol. Substantially lower tensiomyography results in the rectus femoris (RF) were reported, irrespective of the exercise mode performed. Also, no substantial differences were obtained in the biceps femoris (BF) between EOEs and the HS protocol. Time of contraction (Tc) in the RF was possibly to very likely lower in the HS in comparison to EOEs. Additionally, muscular displacement (Dm) in the RF was substantially lower in the HS compared to EOEs. VP produced higher concentrations of damage markers than YIT and concentric exercise did. Furthermore, tensiomyography variables showed similar activation in both exercises, although higher specific fatigue (in the RF) was registered in the traditional HS.
... During a 30-minute submaximal run, greater coactivation of biarticular leg muscles was related to better RE (21). Furthermore, fatigue has been shown to change muscle coordination strategy (36). ...
The purpose of this study was to examine the relationship between fatigue-induced changes in running economy (RE) and muscular strength endurance (MSE). Ten well-trained male runners completed 2 runs of the same energy expenditure at 20%Δ VO(2) below LT. In the middle of the experimental condition (high intensity exercise [HIE]), there was a 4-minute block at sVO(2)max. The aim of the 4-minute block was to increase RE through fatigue, without inducing exhaustion. The MSE of hip extensors (HEs) and knee flexors (KFs) was assessed by 2 20-second eccentric bouts on an isokinetic dynamometer at 180°·s(-1). The RE increased after HIE compared to the control condition. Partial correlations found the increase in RE was strongly related with KF MSE (r = -0.709-0.798; p = 0.03-0.01). Greater MSE appeared to confer a fatigue resistant effect, resulting in a smaller increase in RE. The underlying mechanism of the fatigue resistant effect remains to be elucidated. Conditioning work focusing on augmenting eccentric muscular endurance of the legs may offer beneficial adaptations that promote fatigue resistance.
... The existence of an elastic energy transfer could be supported by the high correlations observed (Table 3) between Δpeak power and Δvertical stiffness in both conditions. In this regard, Vuorimaa et al. (27) previously observed a lowering in electromyographic activity with a concurrent increment in mean power during half squat exercises, thus suggesting a possible increase in elastic energy transfer after various running-conditioning protocols. More recently, Moir et al. (18) reported a greater stiffness increment after high-intensity, when compared with highvolume, back squats but with no augmentation of the jump height. ...
The aim of this study was to evaluate the acute effect of a half squat exercise performed with different set configurations on jump potentiation. Twelve resistance-trained men were evaluated on three occasions separated by 48-96 hrs. First, they performed a 5 repetitions maximum test (5RM). Subsequently, they performed in a randomized order two sessions: one session with 5RM until failure, and another session with the same workload but with 30 s rest intervals between repetitions (i.e. cluster set; CS). Countermovement jump performance was examined during the second and third sessions for jump height and force-time parameters using a force platform at the following time intervals: before and at 1, 3, 6, 9, and 12 min. Separate comparisons for each variable at the different time intervals were analyzed using ANOVA, effect size, and qualitative inferences. The majority of the parameters improved independently of the time they occur, except peak force and vertical stiffness after a set until failure. For peak power, it appears the cluster treatment resulted in superior potentiation at 1 min whereas the 5RM treatment resulted in greater potentiation at 9 min. Effect size analysis and qualitative outcomes revealed an improvement in vertical stiffness and a lowering in the depth of the countermovement in CS. There were significant correlations between participants' 5RM relative performance and various force-time parameters only in CS. It appears that a CS induces greater peak power than a 5RM set at 1 min, although the reverse occurs at 9 min. Delayed potentiation associated with the 5RM may be attributed to greater fatigue versus the CS approach. Therefore, it follows that the optimal method for inducing peak power potentiation is dependent on the available time between heavy half-squat exercise and subsequent jump performance.
... In order to reduce cable movement artefact, cables were secured using elastic bands (Vetrap TM ) [23]. An amplifier (gain 6 600, input impedance 2 GV, common-mode rejection ratio 100 dB, bandpass filter 6–1500 Hz; Biochip Grenoble, France) was used [24]. The Muscle Lab Encoder converted the amplified EMG raw signal to root mean square (RMS) signal total error 60.5%. ...
The biomechanical management of bioenergetics of runners when running uphill was investigated. Several metabolic and mechanical variables have been studied simultaneously to spread light on the locomotory strategy operated by humans for effective locomotion. The studied variables were: heart rate, heart rate variability, oxygen intake and blood lactate, metabolic cost, kinematics, ground reaction force and muscular activity. 18 high-level competitive male runners ran at 70% VO2max on different uphill slope conditions: 0%, 2% and 7%. Modifications were significant in almost all variables studied, and were more pronounced with increasing incline. Step frequency/length and ground reaction force are adjusted to cope with both the task of uphill progression and the available (limited) metabolic power. From 0% to 7% slope, step frequency and ground reaction force and metabolic cost increased concurrently by 4%, 12% and 53%, respectively (with a 4% step length decrease as well). It is hypothesised that this biomechanical management is allowed by an environment-body communication performed by means of specific muscular activity.
... The effects of moderate-volume endurance exercises on power do not seem to be clear in the literature. While some studies have reported non-significant changes in countermovement jump performance (Vuorimaa, Vasankari, & Rusko, 2000), others have reported significant improvements (Boullosa & Tuimil, 2007;Vuorimaa, Virlander, Kurkilahti, Vasankari, & Häkkinen, 2006). Thus, it is reasonable to hypothesize that power is not reduced after moderate endurance training. ...
The aim of this study was to examine the acute effects of endurance exercise on jumping and kicking performance in young soccer players. Twenty-one top-class young soccer players (16.1±0.2 years) performed a countermovement jump test and a maximal instep soccer kick test before and after running for 20 min on a treadmill at 80% of their individual maximum heart rate. Two force platforms were used to obtain the following parameters during the countermovement jump: jump height, maximum power, maximum power relative to body mass, maximum vertical ground reaction force, maximum vertical ground reaction force relative to body mass, and maximum vertical ground reaction force applied to each leg. Maximum vertical ground reaction force and maximum vertical ground reaction force relative to body mass applied to the support leg during the kicks were also calculated with a force platform. The kicking motion was recorded using a three-dimensional motion-capture system. Maximum velocity of the ball, maximum linear velocity of the toe, ankle, knee and hip, and linear velocity of the toe at ball contact during the kicks were calculated. Non-significant differences were found in the parameters measured during the countermovement jump and the maximal instep soccer kick test before and after running, suggesting that the jumping and kicking performances of top-class young soccer players were not significantly affected after 20 min treadmill running at 80% of their individual maximum heart rate.
... endurance exercises has been described [81, 82], maybe suggesting that acute muscular potentiation after endurance running may be also an adaptive characteristic. These observations are reinforced by recent studies on molecular responses to exercise. ...
Every 4 years, approximately 10,000 athletes participate in the Olympic Games. These athletes have dedicated several years of physical training to achieve the best possible performance on a given day. Their preparation has been supported by expert coaches and an army of sport scientists, whose overall responsibility is to ensure that the athletes are in peak condition for their event. Although every athlete prepares specifically for the unique physiological challenges of their event, all athletes have one common characteristic: they are Homo sapiens. They share a unique genome, which is the result of evolutionary forces beyond their individual control. Although studies on the influence of different genetic polymorphisms on selected athletic events have been proven to be of limited utility, a body of evidence-from molecular biology to whole-body measures-suggests that training adaptations are enhanced when the stimulus closely resembles the activity pattern of human ancestors. Because genetic evolutionary changes occur slowly in Homo sapiens, and the traditional physical activity and dietary patterns of Homo sapiens have undergone rapid and dramatic changes in previous centuries, we propose that modern humans are physiologically better adapted to training modes and nutritional strategies similar to the ones that their hominid ancestors evolved on, rather than those supported by modern societies. Such an ancestral pattern was mainly characterized by the prevalence of daily bouts of prolonged, low-intensity, aerobic-based activities interspersed with periodic, short-duration, high-intensity bursts of activity. On some occasions, such activity patterns were undertaken with low carbohydrate availability. Specific activities that enhanced strength and power were typically performed after aerobic activities. We present scientific evidence to support the appropriateness of this model, and we propose that future studies should address this hypothesis in a multitude of different sporting activities, by assessing the genetic responses to and performance-based outcomes of different training stimuli. Such information would provide data on which sport scientists and coaches could better prepare athletes and manage their training process.
... Then the participants began the EIT protocol, which consisted of 12 runs of 400 m, grouped into 4 sets of 3 runs, with a passive recovery period of 1 min between runs and 3 min between sets (4 x 3 x 400 m). Interval training is used in the physical preparation of almost all endurance athletes Vuorimaa et al., 2006) and is characterized by efforts lasting from 60 to 90 s with an intensity of 85-100% of maximal aerobic speed and with a high volume. ...
Although there is no universal definition, high-intensity intermittent training (HIIT) generally refers to repeated short to long bouts of high-intensity exercise – performed at close to 100% VO2max – interspersed with recovery periods.
The main objective of this PhD Thesis was to determine from a multidisciplinary perspective (physiological, neuromuscular and biomechanical) the acute effect of different HIIT protocols in endurance athletes, in addition to examine the adaptations that the inclusion of HIIT sessions in a training programme causes in endurance athletes.
In order to achieve that goal some studies were conducted: i) A systematic review of literature focused on both short- and long-term adaptations after HIIT protocols/interventions in endurance runners (Paper I); ii) Analysis of acute response to a typical HIIT protocol for endurance runners – physiological, neuromuscular and biomechanical – (Papers II, III and IV, respectively); iii) Analysis of acute responses to two different HIIT protocols – a typical HIIT vs. a HIIT based on shorter but faster runs – (Papers V, VI and VII); iv) Effects of a HIIT-based training programme on athletic performance and muscular performance parameters in endurance athletes (Papers VIII and IX).
The major results of this Thesis suggest that: a) Endurance runners can maintain their strength and power levels during HIIT workouts performed at intensities above VVO2max. b) Despite the high levels of exhaustion reached, HIIT protocols did not consistently perturb the running kinematics of trained endurance runners. c) Two different HIIT protocols (10x400 m vs. 40x100 m), with identical volume (4 km) but different average pace (~3 km/h), showed similar data in terms of metabolic and physiological impact. d) A HIIT-based running plan was effective for improving athletic performance in triathletes; this improvement is suggested to be due to improved neuromuscular characteristics.
These findings highlight the importance of HIIT as a training method for endurance runners that leads to a reduction in weekly running distances (risk factor for lower extremity running injuries) and an increase in mean running intensity (deeply associated to running performance) without impairing the neuromuscular performance nor running kinematic characteristics.
... Thus, the study of the interaction among electromyographic and kinematic parameters is important to identify how the action between antagonists and synergists muscles of the lower limb respond to the increase of running intensity and how it changes the characteristics of successive stride cycles [20][21][22]. This study is important to identify features determining or limiting running performance and e87 contributes to a better understanding of human movement dynamics [22][23][24]. ...
Objectif
Analyser l’effet de la vitesse de course sur l’amplitude de la foulée (AF), la fréquence de la foulée (FF), le temps de la foulée (TF) et le signal électromyographique des muscles droit antérieur (DA), vaste externe (VE), vaste médial (VM), tibial antérieur (TA), biceps crural (BC) et gastrocnémien chef latéral (GL).
Méthode
Neuf coureurs bien entraînés ont accompli un protocole incrémental à une vitesse initiale de 10 km.h−1 avec des incréments de 1 km.h−1 toutes les trois minutes jusqu’à l’épuisement. Le signal électromyographique, AF, FF, TF, le coefficient de variation entre foulée et l’association entre les paramètres cinématiques et électromyographique ont été calculés à 60, 80 et 100 % de la vitesse maximale.
Résultats
L’AF, FF, et le signal électromyographique du DA, VM, VE et GL ont augmenté et le TF a décru avec l’augmentation de vitesse de la course. La variabilité du signal électromyographique du VM et du VE était plus élevée que celle du GL alors que la variation du TA a été inférieure par rapport aux autres muscles. La variabilité de l’entre foulée de l’activation musculaire a été différemment liée aux paramètres cinématiques et à leurs variations selon l’augmentation de vitesse.
Conclusion
Le protocole incrémental a autrement élevé le signal électromyographique entre les muscles du membre inférieur : il a augmenté la FF et l’AF et a baissé le TF sans modifier la variabilité de ces variables. La variabilité de l’activation musculaire a été corrélée avec les paramètres cinématiques, pourtant les relations entre ces mesures ont varié selon l’augmentation de vitesse de la course.
... The software (MuscleLab V7.16) displays the time course of displacement and velocity. The choice of this device as the reference instrument was dictated by the fact that has been widely used to evaluate dynamic muscle work (2,5,7,25,27). ...
Lifting velocity may have a great impact on strength training-induced adaptations. The purpose of this study was to validate a method including a metronome and a measurement tape as inexpensive tools for the estimation of mean lifting velocity during the bench press exercise. Fifteen subjects participated in this study. After determining their one repetition maximum (1RM) load, we estimated the maximum metronome rhythm (R) that each subject could maintain in the concentric phase for loads of 40 and 60% of 1RM. To estimate R, the 3 repetitions with highest concentric power, as measured by means of a linear encoder, were selected, and their average duration was calculated and converted to lifting rhythm in beats per minute (bpm) for each subject. The range of motion was measured using a regular tape and kept constant during all exercises. Subjects were instructed to begin with the barbell at arm lengths and lower it in correspondence with the metronome beep. They subsequently performed 5 repetitions at 3 different rhythms relative to R (50, 70, and 90% R) for each training load (40 and 60% of 1RM). A linear encoder was attached to the bar and used as a criterion to measure the vertical displacement over time. For each rhythm, the mean velocity was calculated with the metronome (time) and the reference distance and compared with that recorded by the linear encoder. The SEM for velocity between both testing methods ranged from 0.02 to 0.05 m.s (coefficient of variation, 4.0-6.4%; Pearson's correlation, 0.8-0.95). The present results showed that the use of a metronome and a measurement tape may be a valid method to estimate the mean velocity of execution during the bench press exercise. This simple method could help coaches and athletes achieve their strength training goals, which are partly determined by lifting velocity.
... and knees bent to 90°before jump was completed. Jump heights were calculated from flight time using the equation; h = (f 2 × g)/8 where h = jump, f = height time and g = acceleration due to gravity (Oliver, Armstrong, & Williams, 2008;Vuorimaa, Virlander, Kurkilahti, Vasankari, & Häkkinen, 2006). Two repeats were performed, with a 30-s rest period between the jumps. ...
This 9-month randomised controlled workplace physical activity trial investigated the effects of soccer and Zumba exercise, respectively, on muscle strength, maximal jump height, sit-and-reach flexibility and postural sway among female workers. A total of 107 female hospital employees aged 25–63 were cluster-randomised to a soccer group, a Zumba group or a control group. Training was conducted outside working hours as two to three 1-h weekly sessions the first 3 months and once a week the last 6 months. Tests were conducted at baseline, after 3 and 9 months. The soccer group improved maximal neck extension strength both after 3 (1.2 kg; P < 0.05) and 9 months (1.7 kg; P < 0.01) compared to the control group. The Zumba group improved maximal trunk extension strength (3.1 kg; P = 0.04) after 3 months, with improvements in postural sway velocity moment (−9.2 mm2/s; P < 0.05) and lower limb lean mass (0.4 kg; P < 0.05) after 9 months. No significant intervention effects were revealed in vertical jump height or sit-and-reach flexibility. The present study indicates that workplace-initiated soccer and Zumba exercise may be beneficial for improvement of the neck and trunk strength, which may have preventive effects with regard to future perceived muscle pain in the respective body regions. Furthermore, the Zumba group revealed positive effects on lower limb lean mass and postural sway compared to the control group.
... En este sentido, Ftaiti et al. (2005) encontraron una mejora en la potencia en el CMJ en 6 hombres y 6 mujeres moderadamente entrenados después de una carrera de 40 min Boullosa, D.A. Tuimil, J.L. Tomo XXIII • Nº 3 LA FATIGA, LA RECUPERACIÓN Y LA POTENCIACIÓN EN LA CARRERA DE RESISTENCIA al 65% de la VAM a pesar de correr en un ambiente cálido y húmedo. Posteriormente, Vuorimaa et al. (2006) determinaron unos incrementos en la altura del CMJ después de una prueba incremental hasta la extenuación (MR), una carrera continua (TR) y una carrera interválica (2:2 min) al 80% de la VAM durante 40 min. Este incremento en la altura del CMJ después de la prueba progresiva en tapiz, correlacionó positivamente con parámetros como el volumen de entrenamiento, la VAM y el nivel de lactato sanguíneo, y con signo negativo con el máximo CMJ, el 1 RM en ½ sentadilla y la máxima velocidad en 20m, siendo el primer trabajo que encuentra relaciones estadísticamente signifi cativas entre parámetros de rendimiento neuromuscular, parámetros de entrenamiento y el rendimiento aeróbico en corredores de resistencia. ...
En este trabajo abordaremos el estudio de la fatiga, la recuperación y la potenciación en los deportes de resistencia, especialmente en la carrera, como un ejemplo para clarificar la coexistencia de estos procesos en la fase o periodo post-esfuerzo. Dada la naturaleza heterocrónica y sinérgica de estos fenómenos, creemos relevante el estudio de la etiología y la evolución de los mismos para un mejor abordaje del proceso de entrenamiento y de la competición.
... Notwithstanding the previous issues relating to strength performance, there is some suggestion that performing an endurance-type stimulus can have a potentiating effect and thus a positive acute effect on strength performance [12,14,18,25,27,30]. However, this has been reported almost exclusively in trained endurance athletes. ...
When strength training is conducted subsequent to endurance loading, central and peripheral fatigue mechanisms can contribute to decremented strength-type performance. Any decremented strength performance may be influenced by programme variables including the relief period between endurance and strength loadings, the modality, volume and intensity of endurance loading, and the method by which strength-type performance is assessed. The aforementioned programme variables are discussed here, as is the possible potentiating effect of endurance loading, on strength performance. The available evidence base is reviewed and implications for practice and recommendations for effectively programming strength training/performance around endurance loadings are presented.
... Tem sido demonstrado que músculos monoarticulares desempenham importante papel na produção de movimento na articulação do joelho, enquanto que músculos biarticulares, como o BF, parecem fornecer ajustes refinados no controle da distribuição dos torques produzidos nestas articulações 20,21 . Obviamente, também é possível que as diferenças específicas no BF sejam consequência de características individuais dos sujeitos avaliados neste estudo 22 . ...
INTRODUÇÃO:
Testes incrementais de corrida permitem a determinação de limiares metabólicos e neuromusculares. O objetivo do presente estudo foi comparar índices eletromiográficos e metabólicos entre dois protocolos incrementais de corrida com diferentes intervalos entre cada estágio de velocidade.
MÉTODOS:
Participaram do estudo 14 voluntários do sexo masculino. Os protocolos incrementais de corrida em esteira iniciaram em 8 km.h⁻¹, com incremento de 1 km.h⁻¹ a cada três minutos até a exaustão voluntária. Os dois protocolos diferiram quanto aos intervalos entre cada estágio de velocidade: 30 segundos (protocolo 1) e 120 segundos (protocolo 2). O limiar de fadiga eletromiográfico (LFEMG) foi determinado para os músculos reto femoral, bíceps femoral, tibial anterior e gastrocnêmio lateral. Para tanto, o comportamento do valor RMS foi correlacionado em função do tempo de corrida, sendo realizada regressão linear para determinação dos coeficientes de inclinação. O limiar de lactato foi identificado por meio do ponto de inflexão na curva lactato-intensidade e o limiar anaeróbio foi determinado por meio de interpolação linear. Foi aplicado um teste t de Student para dados pareados (p<0,05).
RESULTADOS:
Foi verificado que o protocolo 2 apresentou velocidade de LFEMG maior do que o protocolo 1, apenas para o músculo BF (p=0,023), o que caracteriza uma resposta específica deste músculo em protocolos incrementais de corrida.
CONCLUSÃO:
Protocolos de corrida com intervalos de até dois minutos entre os estágios incrementais apresentaram resultados semelhantes para determinação do LFEMG da maioria dos músculos estudados e dos limiares metabólicos.
... and on T conc 1.496 ± 0.317 mV in trial 1 and 1.575 ± 0.444 mV (r = 0.91, P < .001) in trial 2, as previously performed. [36,37] ...
This study was aimed to investigate the neuromuscular activity after 10 minutes of exposure to a whole body vibration (WBV) session.
Twenty male young adults (24.8 ± 2.5 year olds) were randomized and divided into 2 groups: the vibration group (VG) was exposed to 10 minutes of WBV at 35 Hz; performed 10 minutes of WBV at 35 Hz (displacement = 5 mm; magnitude = 5 g); the nonvibrated group (NVG) was the placebo group that maintained the same position on the plate but without exposure to any type of vibration. Subjects were evaluated with counter movement jump (CMJ) and muscular flexibility by means of electromyographic (EMG) analysis recorded on the vastus lateralis (VL), vastus medialis (VM), biceps femoris (BF), and gastrocnemius lateralis (LG).
The 10 minutes of WBV showed an increase in muscular flexibility, associated with a decrease of EMG activity in BF (P < .01) and jump height. The latter was associated with a reduction of EMGs activity in BF (P < .01). The control group did not show any significant difference in all considered parameters.
These results support the hypothesis that 10 minutes of WBV had effects on flexibility and explosive strength performance influencing neuromuscular behavior through inhibitor effects on antagonist muscles more than the stretch reflex activity on agonist muscles.
... Thus, the performance enhancement depends on the prevalence of PAP mechanisms over fatigue mechanisms, which is modulated by several factors including, but not limited to, sociodemographic characteristics of subjects like sex (Russ et al., 2008) or training experience (Kilduff et al., 2007), the recovery time (Gołaś et al., 2016;Kilduff et al., 2008), and the type, intensity as well as volume of the conditioning activity (CA) performed (Gołaś et al., 2016;Wilson et al., 2013). explosive, shorter and intensive stimuli can be used as a CA, but also sub-maximum and longer or prolonged exercises can cause PAP for subsequent activities (Boullosa and Tuimil, 2009;Boullosa et al., 2011;García-Pinillos et al., 2015;Vuorimaa et al., 2006). Hamada et al. (2000) indicated that endurance training caused, on one hand, a greater amount of phosphorylation of regulatory myosin light chains in slow fibers, and on the other hand, greater resistance to fatigue, which would allow the prevalence of potentiation as well as explain the PAP presence in endurance athletes. ...
The present study analyzed the acute effects of an incremental running test on countermovement jump (CMJ) and handgrip strength performance in endurance athletes, considering the effect of post-exercise recovery time and sex. Thirty-three recreationally trained long-distance runners, 20 men and 13 women, participated voluntarily in this study. The participants performed the Léger test, moreover, the CMJ and handgrip strength tests were carried out before and after the running test and during different stages of recovery (at the 1st min of recovery (posttest1), 5th min of recovery (posttest2), and 10th min of recovery (posttest3)). Two-way analysis of variance revealed a significant improvement in the CMJ (pre-posttest1
... VUORIMAA et al. 29 verificaram que após corridas intensas foram utilizadas diferentes estratégias de coordenação entre os músculos agonistas e antagonistas extensores do joelho. Entretanto, diferentemente dos resultados encontrados no presente estudo, o processo de fadiga induzido por exercícios intensos levou a redução do sinal EMG dos músculos vasto lateral e vasto medial, enquanto que não foram encontradas diferenças significativas no sinal EMG do músculo bíceps femoral. ...
Running and cycling executed with the same duration and intensity may produce different biomechanical and metabolical responses during a fatigue protocol due to the mechanical overload and technical specificity of each modality. The purpose of this study was to evaluate the fatigue effects resultant from a 10 km running, preceded by cycling or running, on the stride pattern and electromyographic (EMG) signal. Nine male triathletes with over two years of experience participated in the study. The tests were carried out in two phases: triathlon running (40 km of cycling followed by 10 km of running) and prolonged running (running with equal duration of time of the 40 km of cycling, followed by more 10 km of running). Kinematic analysis (stride frequency and amplitude) and EMG analysis were performed on ten strides recorded at the 5th km and at the 10th km (final running period). The EMG curves were rectified and filtered prior to the calculation of the RMS curves. From the average of the ten EMG curves, the peak RMS values for the following muscles were obtained: rectus femoris, vastus lateralis, biceps femoris. Higher stride frequency and EMG signals were obtained for biceps femoris muscle on the prolonged compared to the triathlon running. These results seem related to a higher fatigue in the prolonged running due to it's higher mechanical demands.
... Vuorimaa et al. 29 verified after intense running that agonists and antagonists muscle of knee extension movement were activated differently: was observed reduction on EMG signal of VL and VM muscles, while there were no significant differences found on EMG signal of BF muscle. During the running, biarticular muscles as BF and RF may present a double burst characterizing its respective function on hip and knee joints, while GA muscle, although biarticular, presents only one characteristic burst of ankle plantar flex. ...
Aim. The objective of this study was to compare electromyographic signal (EMG), stride length (SL) and stride frequency (SF) in three different speeds during an incremental running protocol on a treadmill. Methods. Eleven male recreational runners performed an incremental running protocols on treadmill with an initial speed of 10 km/h and increments of 1 km/h every three minutes, with 30s intervals between each speed increase, up to exhaustion. The EMG signal was obtained of theiliocostalis lumborum (IC), rectus femoris (RF), vastus lateralis (VL), vastus medialis (VM), biceps femoris (BF), tibialis anterior (TA) and gastrocnemius lateralis (GL) muscles. The RMS (Root Mean Square) values of each muscle and the kinematic data (SL and SF) were calculated considering the mean of the ten last strides, and compared in the three intensities: 60%, 80% and 100% of the maximal speed (Vmax). Results. The RMS values corresponding to 100% were greater than 60% and 80% for IC, RF, VL, BF and GL, and those corresponding to 80% were greater than 60% for IC, RF and GL (P<0.05). For TA the values corresponding to 100% were only greater than 60% of the Vmax (P<0.05). The SL and SF values corresponding to 100% were greater than 60% and 80%, and 80% were greater than 60% (P<0.05). Conclusion. The EMG signal showed higher values with increasing speed, but this has not been a behavioral pattern to the muscles analyzed in this study. Furthermore, the increase in running speed was achieved through both SL and SF.
We evaluated possible methods of normalising EMG measured during running. MVC, Sprint and 70% Peak Running Speed methods were evaluated and their repeatability, reliability and sensitivity to incremental running speed were compared. Twelve runners performed the same experimental protocol on three separate occasions. Each day, subjects firstly performed MVCs, followed by a 20 m maximal sprint (with a 20-30 m run-up). Following this, they performed the peak running speed (PRS) test until exhaustion. After which they ran at 70% of PRS for 5 laps. Results indicated that normalising EMG data to MVC and Sprint methods are more repeatable for VM, BF, MG and RF, VL, LG, respectively, with the average ICC>0.80. The 70% PRS demonstrated poor to fair levels of repeatability ranging between ICC 0.27 and 0.70. Whereas the 70% PRS method had the least intra-subject variability and the greatest sensitivity to increasing running speeds. More specifically, demonstrating significant changes in muscle activity in VM with increasing running speed while MVC and Sprint methods were unable to detect these changes. The dynamic methods were the most appropriate for EMG normalisation showing repeatability, better intra-subject reliability and better sensitivity during running over different days and for once-off measurements.
The aim of this study was to compare the electromyographic signal and the stride frequency and length among different intensities of running: 60%, 80% and 100% of maximum speed in two incremental protocols. The study included 11 male runners. The protocols were performed with initial running speed of 10 km.hr-1, with increments of 1 km.hr-1 at every three minutes until exhaustion. The two protocols differed in the interval between each incremental stage: 30 to 120 seconds. We analyzed RMS values of the iliocostalis lumbar, rectus femoris, vastus lateralis, vastus medialis, biceps femoris, tibialis anterior, gastrocnemius lateralis, and the stride length and frequency. The RMS values showed an increase among intensities for almost all muscles, and were not influenced by the type of protocol used for most muscles. The contribution of stride length and frequency were percentile different as the running speed increased.
Purpose:
To quantify how whole-body power, muscle-function, and jump-performance measures change during prolonged cycling and recovery and determine whether there are relationships between the different fatigue measures.
Methods:
Ten competitive or recreationally active male cyclists underwent repeated 20-min stages of prolonged cycling at 70% VO2peak until exhaustion. Whole-body peak power output (PPO) was assessed using an all-out 30-s sprint 17 min into each cycle stage. Ratings of perceived exertion (RPE) were recorded throughout. Isometric and isokinetic muscle-function tests were made between cycle stages, over ~6 min, and during 30-min recovery. Drop-jump measures were tested at exhaustion and during recovery.
Results:
PPO initially increased or was maintained in some subjects but fell to 81% of maximum at exhaustion. RPE was near maximal (18.7) at exhaustion, with the time to exhaustion related to the rate of rise of RPE. PPO first started to decline only when RPE exceeded 16 (ie, hard). Peak isometric and concentric isokinetic torque (180°/s) for the quadriceps fell to 86% and 83% of pretest at exhaustion, respectively. In contrast, the peak concentric isokinetic torque (180°/s) of the hamstrings increased by 10% before declining to 93% of maximum. Jump height fell to 92% of pretest at exhaustion and was correlated with the decline in PPO (r = .79). Muscle-function and jump-performance measures did not recover over the 30-min postexercise rest period.
Conclusions:
At exhaustion, whole-body power, muscle-function, and jump-performance measures had all fallen by 7-19%. PPO and drop-jump decrements were linearly correlated and are appropriate measures of maximal performance.
The aim of this study was to investigate the effects of gradients (0, 2 and 7%) on biomechanical parameters during race-walking (RW) at Iso-Efficiency Speed (IES). During the experiment twelve high level athletes performed at IES on different slopes. The parameters studied were: surface muscular activity (sEMG) of five muscles of the leg using Muscle Lab; kinematic parameters were collected using a high speed camera (210 Hz) analyzed with Dartfish 5.5Pro and heart rate was monitored with a Cardio Polar. The results showed step length (SL), step frequency (SF) and internal work (WINT) decreased with increased treadmill gradient: SL= [(0-2%= 3.48%, p= 0.158), (0-7%= 12.17%, p< 0.001)]; SF= [(0-2%= 2.38%, p= 0.173), (0-7%= 6.07%, p< 0.01)]; WINT= [(0-2%= 8.34%, p< 0.001), (0-7%= 22.81%, p< 0.0001)]. Conversely contact time (CT) and heart rate (HR) increased less significantly with the increased gradients: CT= [(0-2%= 2.46%, p= 0.198), (0-7%= 6.56%, p< 0.01)]; HR= [(0-2%= 0.62%, p= 0.652), (0-7%= 3.25%, p< 0.05)]. The knee angle (KE) increased, while ankle angle (AK) and hip angle (HP) decreased with the increased gradients. AK= [(0-2%= 1.69%, p< 0.001), (0-7%= 1.13%, p< 0.01)]; HP= [(0-2%= 0.22%, p< 0.03), (0-7%= 0.16%, p= 0.456)]; KE= [(0-2%= 1.01%, p< 0.001), (0-7%= 1.60%, p< 0.001)]. EMG significantly decreased with the increased gradients in the: tibialis anterior [(0-2%= 22.49%, p< 0.0001), (0-7%= 41.18%, p< 0.0001)] and rectus femoris [(0-2%= 15.35%, p< 0.0001), (0-7%= 29.13%, p< 0.0001]. In contrast, EMG activity was significantly increased in the vastus lateralis [(0-2%= 22.95%, p< 0.0001), (0-7%= 31.15%, p< 0.0001)], gastrocnemius medialis [(0-2%= 21.40%, p< 0.001), (0-7%= 48.37%, p< 0.0001] and biceps femoris [(0-2%= 190.78%, p< 0.0001), (0-7%= 201.37%, p< 0.0001]. The results indicate that increasing the gradient to 2% did not elicit an increased heart rate in race walkers, however at a 7% gradient greater muscle activity was required.
Introduction:
We examined the individual patterns of responses for electromyographic (EMG) amplitude and mean power frequency (MPF) during incremental treadmill running.
Methods:
Nine physically active men performed incremental treadmill running at a constant grade of 1%. The EMG signal was recorded from the 3 superficial quadriceps femoris muscles during the work bout.
Results:
The results of the polynomial regression indicated that the linear model best fit the data for the composite data for all 3 muscles and the majority (7 of 9) of subjects. There were no consistent patterns of responses for the EMG MPF responses. Also, there were no significant (P > 0.05) muscle × running velocity interactions for EMG amplitude and MPF.
Conclusions:
These results indicate consistent patterns of responses for EMG amplitude during incremental treadmill running, regardless of which muscle was studied.
Soccer refereeing demand a high neuromuscular implication which it could produce accumulative fatigue and keep down the physical performance of soccer referees. The aims of this study were 1) to describe the performance in an incremental maximum test and in the bilateral and unilateral vertical jump (VJ) capacity in soccer referees, and 2) to analyze the variation on the VJ capacity after performing a maximum incremental test. Before and after performing a cardiovascular incremental test, VJ capacity was measured in 12 high-level soccer referees who officiated at high Spanish competitive-level. On one side, post activation potentiation (PAP) effect was not produced because the improvement of VJ was trivial-small (p > 0,05; ∆ = 0,10-2,19%; d = 0,01-0,21). On the other side, due to the associations between VJ variation and maximum values on the incremental test were small in many cases (r=-0,25/0,24), it could happen that the fatigue induced by the incremental maximum test is not associated to a loss of performance in the vertical jump capacity in high-level soccer referees.
The level of hypohydration at which power output during intermittent-exercise performance starts to decrease is not fully understood. The purpose of this study was to investigate the effects of 2% hypohydration without hyperthermia on intermittent-exercise performance. Eight collegiate amateur boxers completed two exercise tests. On day 1, subjects hypohydrated by 2% of body mass by exercising in a hot environment, and on day 2, subjects performed intermittent exercise (4 × 2 min/round [R] separated by 1-min recovery) under a randomly assigned condition of with (HYP) or without (EUH) hypohydration. Each bout consisted of 8 × 5 s of maximal cycling exercise (0.05 kp × body mass) separated by 10 s of passive recovery. Mean power output/kg (MPO); total power output/kg (TPO); energy system relative contribution; and core rectal temperature (Tre) were measured. Changes in body mass before the exercise tests were -2.25 ± 0.18% (HYP) and -0.17 ± 0.19% (EUH) (p < 0.001). MPO, TPO, and each energy contribution ratio were not significantly different between the trials, and pre- and post-exercise-test Tre did not differ significantly between trials. Results demonstrated that approximately 2% hypohydration lies below the point at which power output during intermittent exercise starts to decline.
The aim of this study was to investigate the effects of gradients (0, 2 and 7%) on biomechanical parameters during race walking (RW) at Iso-Efficiency Speed (IES). During the experiment twelve high level athletes performed at IES on different slopes. The parameters studied were: surface muscular activity (sEMG) of five muscles of the leg using Muscle Lab; kinematic parameters were collected using a high speed camera (210 Hz) analyzed with Dartfish 5.5Pro and heart rate was monitored with a Cardio Polar. The results showed step length (SL), step frequency (SF) and internal work (WINT) decreased with increased treadmill gradient: SL= [(0-2%= 3.48%, p= 0.158), (0-7%= 12.17%, p< 0.001)]; SF= [(0-2%= 2.38%, p= 0.173), (0-7%= 6.07%, p< 0.01)]; WINT= [(0-2%= 8.34%, p< 0.001), (0-7%= 22.81%, p< 0.0001)]. Conversely contact time (CT) and heart rate (HR) increased less significantly with the increased gradients: CT= [(0-2%= 2.46%, p= 0.198), (0-7%= 6.56%, p< 0.01)]; HR= [(0-2%= 0.62%, p= 0.652), (0-7%= 3.25%, p< 0.05)]. The knee angle (KE) increased, while ankle angle (AK) and hip angle (HP) decreased with the increased gradients. AK= [(0-2%= 1.69%, p< 0.001), (0-7%= 1.13%, p< 0.01)]; HP= [(0-2%= 0.22%, p< 0.03), (0-7%= 0.16%, p= 0.456)]; KE= [(0-2%= 1.01%, p< 0.001), (0-7%= 1.60%, p< 0.001)]. EMG significantly decreased with the increased gradients in the: tibialis anterior [(0-2%= 22.49%, p< 0.0001), (0-7%= 41.18%, p< 0.0001)] and rectus femoris [(0-2%= 15.35%, p< 0.0001), (0-7%= 29.13%, p< 0.0001]. In contrast, EMG activity was significantly increased in the vastus lateralis [(0-2%= 22.95%, p< 0.0001), (0-7%= 31.15%, p< 0.0001)], gastrocnemius medialis [(0-2%= 21.40%, p< 0.001), (0-7%= 48.37%, p< 0.0001] and biceps femoris [(0-2%= 190.78%, p< 0.0001), (0-7%= 201.37%, p< 0.0001]. The results indicate that increasing the gradient to 2% did not elicit an increased heart rate in race walkers, however at a 7% gradient greater muscle activity was required.
Nine experienced endurance runners performed individual marathon runs that involved several tests of neuromuscular performance before, during and after the marathon. The tests were performed with special force platform and dynamometer techniques. The results showed an overall decrease in performance from the marathon. The maximal sprint velocity decreased parabolically during the marathon, reaching the final value of 84% of the pre-marathon one. Similarly, the other test results after marathon indicated that maximal isometric knee extension torque was 78%, the performance in a special rebound test (drop jump) 84% and the 5-jump performance 92% of the pre-marathon values. These reductions were accompanied by alteration in the ground reaction force curves in the sprint and jump tests, suggesting reduced tolerance to stretch load as well as loss in the recoil characteristics of the muscles.
The purpose of this study was to assess the reproducibility of running time to exhaustion (Tlim) at maximal aerobic speed (MAS: the minimum speed that elicits VO2max), on eight subelite male long distance runners (29 +/- 3-yr-old; VO2max = 69.5 +/- 4.2 ml.kg(-1).min(-1); MAS = 21.25 +/- 1.1 km.h(-1)). No significant differences were observed between Tlim measured on a treadmill at a 1-wk interval (404 +/- 101 s vs 402 +/- 113 s; r = 0.864); however, observation of individual data indicates a wide within-subjects variability (CV = 25%). In a small and homogenous sample of runners studied, exercise time to exhaustion at MAS was not related to VO2max (r = 0.138), MAS (r = 0.241), running economy (mlO(2).kg(-1).min(-1) at 16 km.h(-1)) (r = 0.024), or running performance achieved for 3000 m (km.h(-1)) (r = 0.667). However, Tlim at MAS was significantly related to the lactate threshold determined by the distinctive acceleration point detected in the lactate curve around 3-5 mmol.l(-1) expresses in %VO2max (r = 0.745) and to the speed over a 21.1-km race (km.h(-1)) (r = 0.719). These data demonstrate that running time to exhaustion at MAS in subelite male long distance runners is related to long distance performance and lactate threshold but not to VO2max or MAS.
The influence of an individual marathon race was investigated among 7 subjects who performed 2 types of unilateral isometric strength tests before and after the race. The tests included maximal isometric voluntary actions (MVA) of the knee extensor muscles and isometric endurance of 60% of pre-marathon MVA. The results showed dramatic reductions of the maximal isometric torque (26 ± 14%) and endurance time (39 ± 9%). Maximal integrated electromyographic activity (IEMG) of the vastus medialis muscle decreased by 36 ± 26% and that of the vastus lateralis muscle by 42 ± 25%. In the submaximal endurance test, the post-marathon isometric knee extension started at a higher level of IEMG and lower mean power frequency (MPF) for 6 of 7 subjects. These data suggest that the repeated stretch-shortening cycles during the marathon race affected the force production by reducing neural input to the muscles and deteriorating the efficacy of the contractile mechanism.
This article traces the history of scientific and empirical interval training. Scientific research has shed some light on the choice of intensity, work duration and rest periods in so-called ‘interval training’. Interval training involves repeated short to long bouts of rather high intensity exercise (equal or superior to maximal lactate steady-state velocity) interspersed with recovery periods (light exercise or rest). Interval training was first described by Reindell and Roskamm and was popularised in the 1950s by the Olympic champion, Emil Zatopek.
Since then middle- and long- distance runners have used this technique to train at velocities close to their own specific competition velocity. In fact, trainers have used specific velocities from 800 to 5000m to calibrate interval training without taking into account physiological markers. However, outside of the competition season it seems better to refer to the velocities associated with particular physiological responses in the range from maximal lactate steady state to the absolute maximal velocity. The range of velocities used in a race must be taken into consideration, since even world records are not run at a constant pace.
The purpose of this study was to investigate neuromuscular and energy performance characteristics of anaerobic power and capacity and the development of fatigue. Ten endurance and ten sprint athletes performed a new maximal anaerobic running power test (MARP), which consisted of n x 20-s runs on a treadmill with 100-s recovery between the runs. Blood lactate concentration [la-]b was measured after each run to determine submaximal and maximal indices of anaerobic power (P3 mmol.l-1, P5 mmol.l-1, P10 mmol.l-1 and Pmax) which was expressed as the oxygen demand of the runs according to the American College of Sports Medicine equation: the oxygen uptake (ml.kg-1.min-1) = 0.2 x velocity (m.min-1) + 0.9 x slope of treadmill (frac) x velocity (m.min-1) + 3.5. The height of rise of the centre of gravity of the counter movement jumps before (CMJrest) and during (CMJ) the MARP test, as well as the time of force production (tF) and electromyographic (EMG) activity of the leg muscles of CMJ performed after each run were used to describe the neuromuscular performance characteristics. The maximal oxygen uptake (VO2max), anaerobic and aerobic thresholds were determined in the VO2max test, which consisted of n x 3-min runs on the treadmill.(ABSTRACT TRUNCATED AT 250 WORDS)
Fatigue during the 400-m sprint was studied by measuring muscle ATP, creatine phosphate (CP), lactate (M-La), and blood lactate (B-La) in six male runners before and after four experimental sprints (100, 200, 300, and 400 m). During the first 100 m, muscle CP decreased from 15.8 +/- 1.7 to 8.3 +/- 0.3 mmol/kg while M-La increased to 3.6 +/- 0.4 mmol/kg. After 200 m the CP had decreased to 6.5 +/- 0.5 mmol/kg and M-La had increased to 8.3 +/- 1.1 mmol/kg. At the end of the 400 meters, ATP and CP concentrations had decreased by 27% and 89%, respectively, and M-La had increased to 17.3 +/- 0.9 mmol/kg. It was concluded that after 200 m the speed of running decreased, although CP was not depleted and lactate concentration was not at maximum level. Complete fatigue occurred when CP stores were depleted and B-La and M-La attained an individual maximum.
To examine endogenous anabolic hormone and growth factor responses to various heavy resistance exercise protocols (HREPs), nine male subjects performed each of six randomly assigned HREPs, which consisted of identically ordered exercises carefully designed to control for load [5 vs. 10 repetitions maximum (RM)], rest period length (1 vs. 3 min), and total work effects. Serum human growth hormone (hGH), testosterone (T), somatomedin-C (SM-C), glucose, and whole blood lactate (HLa) concentrations were determined preexercise, midexercise (i.e., after 4 of 8 exercises), and at 0, 5, 15, 30, 60, 90, and 120 min postexercise. All HREPs produced significant (P less than 0.05) temporal increases in serum T concentrations, although the magnitude and time point of occurrence above resting values varied across HREPs. No differences were observed for T when integrated areas under the curve (AUCs) were compared. Although not all HREPs produced increases in serum hGH, the highest responses were observed consequent to the H10/1 exercise protocol (high total work, 1 min rest, 10-RM load) for both temporal and time integrated (AUC) responses. The pattern of SM-C increases varied among HREPs and did not consistently follow hGH changes. Whereas temporal changes were observed, no integrated time (AUC) differences between exercise protocols occurred. These data indicate that the release patterns (temporal or time integrated) observed are complex functions of the type of HREPs utilized and the physiological mechanisms involved with determining peripheral circulatory concentrations (e.g., clearance rates, transport, receptor binding). All HREPs may not affect muscle and connective tissue growth in the same manner because of possible differences in hormonal and growth factor release.
The validation of a new dynamometer for evaluation of dynamic muscle work is presented. The device was based on a precise measurement of load displacements of any machine using gravitational loads as external resistance. It allowed, through a sensor consisting of an infrared photo interrupter, the calculation of velocity, force and power during concentric, eccentric and stretch-shortening cycle activity. To validate the dynamometer 33 male and female track and field athletes (12 throwers and 21 jumpers) participated in the study. The throwers (4 women and 8 men) were asked to perform half-squat exercises on a slide machine with a load of 100% of the subject's body mass. The day-to-day reproducibility of half-squat exercises gave a correlation coefficient of r = 0.88, 0.97 and 0.95 for average push-off force (AF), average push-off velocity (AV), and average push-off power (AP) respectively. Comparison of half-squat measurements was performed against jumping and running test evaluation by the jumpers (7 women and 14 men). The interrelationships among the different variables studied demonstrated a strong correlation between AF, AV and AP and sprinting and jumping parameters (r = 0.53-0.97; P < 0.05-0.001). Using values of AF, AV and AP developed in half-squat exercises executed with different loads, ranging from 35% to 210% of the subject's body mass, it was also possible to establish the force-velocity and power-velocity relationships for both male and female jumpers. In any individual case, the maximal error due to the measurement system was calculated to be less than 0.3%, 0.9% and 1.2% for AF, AV, and AP respectively.(ABSTRACT TRUNCATED AT 250 WORDS)
The purpose of this study was to assess the reproducibility of running time to exhaustion (Tlim) at maximal aerobic speed (MAS: the minimum speed that elicits VO2max), on eight subelite male long distance runners (29 +/- 3-yr-old; VO2max = 69.5 +/- 4.2 ml.kg-1.min-1; MAS = 21.25 +/- 1.1 km.h-1). No significant differences were observed between Tlim measured on a treadmill at a 1-wk interval (404 +/- 101 s vs 402 +/- 113 s; r = 0.864); however, observation of individual data indicates a wide within-subjects variability (CV = 25%). In a small and homogenous sample of runners studied, exercise time to exhaustion at MAS was not related to VO2max (r = 0.138), MAS (r = 0.241), running economy (mlO2.kg-1.min-1 at 16 km.h-1) (r = 0.024), or running performance achieved for 3000 m (km.h-1)(r = 0.667). However, Tlim at MAS was significantly related to the lactate threshold determined by the distinctive acceleration point detected in the lactate curve around 3-5 mmol.l-1 expresses in %VO2max (r = 0.745) and to the speed over a 21.1-km race (km.h-1) (r = 0.719). These data demonstrate that running time to exhaustion at MAS in subelite male long distance runners is related to long distance performance and lactate threshold but not to VO2max or MAS.
The velocity associated with the achievement of VO2 max during an incremental treadmill test (v VO2 max) has been reported to be an indicator of performance in middle distance running events. Previous study has shown the reproducibility of the time to exhaustion (time limit: tlim) at v VO2 max performed by well-trained males in the same condition at one week of interval (Billat et al., 1994b). It is essential in studies involving tlim at v VO2 max that the v VO2 max be precisely determined, or else the measured tlim will be meaningless. The purpose of this study was to examine the influence of the stage duration and velocity incrementation on the velocity at VO2 max and, consequently, on the two times to exhaustion (tlim) associated with the two v VO2 max generated by the two protocols. v VO2 max was determined in 15 trained male endurance athletes as the lowest speed at which VO2 max was attained in speed-incremented 0%-slope treadmill tests. For one test, increments were 1.0 km.h-1 and stages were 2 min in duration; for the other test, increments were 0.5 km.h-1 and stages were 1 min in duration. Results of paired means t-tests revealed no difference in v VO2 max obtained using the two protocols. v VO2 max was 20.7 +/- 1.0 km.h-1 with the 1.0 km.h-1 x 2 min protocol and 20.8 +/- 0.9 km.h-1 with the 0.5 km.h-1 x 1 min protocol. In addition, VO2, VCO2, VE, VE/VO2 and respiratory exchange ratio at the submaximal intensities that were common to both protocols (e.g., 17.0 km.h-1, 18.0 km.h-1, 19.0 km.h-1, 20.0 km.h-1) did not differ. Times to exhaustion at the two v VO2 max demonstrated a high degree of inter-individual variability (coefficients of variation were 35% and 45%) but did not differ (345 +/- 120 s versus 373 +/- 169 s). These results demonstrated that small changes in protocol have no significant impact on the value of v VO2 max and in consequence on tlim v VO2 max.
Three modifications of the maximal anaerobic running test (MART) were compared in sprinters (Spr, n = 5), middle-distance runners (Mid, n = 5) and marathon runners (Mar, n = 6). The MART1, MART3 and MART5 consisted of n sets of 1.20-s, 3.20-s and 5.20-s runs, respectively, on a treadmill with 40-s recovery between the runs and 100-s recovery between the sets. In each MART the velocity of the first set of runs was 3.0 m.s-1 and the slope 4 degrees. Thereafter, the velocity was gradually increased by 0.38 m.s-1 for each consecutive set until exhaustion. After each set and after exhaustion fingertip blood samples were taken to determine lactate concentration and three counter-movement jumps (CMJ) were performed. Maximal (Pmax) and submaximal (P4mM) running power in each MART was expressed as the oxygen demand (ml.kg-1.min-1) of the runs. In MART1, Mar had a significantly lower Pmax than Mid or Spr (mean +/- SD; 97.8 +/- 5.4 vs. 121.0 +/- 4.4 vs. 119.2 +/- 5.4 ml.kg-1.min-1), while in MART3 the groups did not differ significantly, and the sprinters were unable to perform MART5. Mar, Mid and Spr attained the lower Pmax the more runs per set in MART (p < 0.01). Mar had the higher peak blood lactate the more runs each set consisted of (p < 0.001). In Mid and Spr, the peak blood lactate did not differ significantly between the MARTs but was significantly higher than the corresponding peak blood lactate of the marathon runners. Pmax in MART1 correlated positively with maximal 20-m sprinting speed on a track and with CMJ height (p < 0.001, n = 16) but negatively with VO2 max (p < 0.001, n = 16) while in MART3 no significant correlations were found. It was concluded that the n.1.20-s protocol should be used to measure the maximal anaerobic power of all runners. However, in long-distance runners more runs per set may be needed to evaluate their anaerobic capacity.
Previous studies had concluded that the treadmill velocity-endurance time hyperbolic relationship for runs could be accuratly approached with a regression at condition that bouts of exercise duration were included between 2 and 12 min. This regression allows to calculate the critical speed (CS) defined as the slope of the regression of work (distance) on time to exhaustion, the anaerobic running capacity (ARC) being the intercept of this line (Monod & Scherrer, 1965). The purpose of this investigation was to give practical indication concerning the choice of the velocities in reference to the maximal aerobic speed (MAS i.e. the minimum speed which elicits VO2max). Subjects were fourteen elite male long-distance runners (27 +/- 3 years old; VO2max = 74.9 +/- 2.9 ml.kg-1.min-1, MAS = 22.4 +/- 0.8 km.h-1, CS = 19.3 +/- 0.7 km.h-1 and 86.2 +/- 1.5% MAS). tlim 100 values (321 +/- 83 s) were negatively correlated with MAS (r = -0.538, p < 0.05) and with CS (km.h-1) (r = -0.644, p < 0.01). tlim 90 (1015 +/- 266 s) was positively correlated with CS when expressed in % MAS (r = 0.645, p < 0.01) and not when expressed in km.h-1 (r = -0.095, P > 0.05). tlim 105 (176 +/- 40 s) only was correlated with ARC (r = 0.526, p < 0.05). These data demonstrate that running time to exhaustion at 100 and 105% of MAS in a homogeneous elite male long-distance runners group is inversely related to MAS. Moreover, tlim 90 is positively correlated with CS (%MAS) but neither with tlim 100 and 105 nor with maximal aerobic speed. So from a practical point of view, the velocities chosen to determine the critical speed, would be closed to the maximal aerobic speed (time to exhaustion around 6 min), taking into account that the tlim 105 is correlated with the anaerobic capacity, whereas tlim 90 is correlated with the critical speed.
This study investigated neuromuscular characteristics and fatigue during 10 km running (10 K) performance in well-trained endurance athletes with different distance running capability. Nine high (HC) and ten low (LC) caliber endurance athletes performed the 10 K on a 200 m indoor track, constant velocity lap (CVL, 4.5 m x s(-1)) 5 times during the course of the 10 K and maximal 20 m speed test before (20 m(b)) and after (20 m(a)) the 10 K. Running velocity (V), ground contact times (CT), ground reaction forces (F) and electromyographic activity (EMG) of the leg muscles (vastus lateralis; VL, biceps femoris; BF, gastrocnemius; GA) were measured during 20 m(b), 20 m(a), and CVLs. The 10 K times differed (p<0.001) between HC and LC (36.3+/-1.2 and 39.2+/-2.0 min, respectively) but no differences were observed in 20 m(b) velocity. The 10 K led to significant (p<0.05) decreases in V, F and integrated EMG (IEMG) and increases in CTs of 20 m(a) in both groups. No changes were observed in HC or LC in F and IEMG during the CVLs but HC showed shorter (p<0.05) mean CT of CVLs than LC. A significant correlation (r = -0.56, p<0.05) was observed between the mean CT of CVLs and velocity of 10 K (V10K). Pre-activity of GA in relation to the IEMG of the total contact phase during the CVLs was higher (p<0.05) in HC than LC. The relative IEMGs of VL and GA in the propulsion phase compared to the IEMG of the 20 m(b) were lower (p<0.05) in HC than LC. In conclusion, marked fatigue took place in both HC and LC during the 10 K but the fatigue-induced changes in maximal 20 m run did not differentiate endurance athletes with different V10K. However, a capability to produce force rapidly throughout the 10 K accompanied with optimal preactivation and contact phase activation seem to be important for 10 km running performance in well trained endurance athletes.
Twitch potentiation and fatigue in skeletal muscle are two conditions in which force production is affected by the stimulation history. Twitch potentiation is the increase in the twitch active force observed after a tetanic contraction or during and following low-frequency stimulation. There is evidence that the mechanism responsible for potentiation is phosphorylation of the regulatory light chains of myosin, a Ca2+-dependent process. Fatigue is the force decrease observed after a period of repeated muscle stimulation. Fatigue has also been associated with a Ca2+-related mechanism: decreased peak Ca2+ concentration in the myoplasm is observed during fatigue. This decrease is probably due to an inhibition of Ca2+ release from the sarcoplasmic reticulum. Although potentiation and fatigue have opposing effects on force production in skeletal muscle, these two presumed mechanisms can coexist. When peak myoplasmic Ca2+ concentration is depressed, but myosin light chains are relatively phosphorylated, the force response can be attenuated, not different, or enhanced, relative to previous values. In circumstances where there is interaction between potentiation and fatigue, care must be taken in interpreting the contractile responses.
The purpose of this study was to analyze the effects of prolonged cycling exercise on metabolic, neuromuscular, and biomechanical parameters.
Eight well-trained male cyclists or triathletes performed a 2-h cycling exercise at a power output corresponding to 65% of their maximal aerobic power. Maximal concentric (CON; 60, 120, 240 degrees x s(-1)), isometric (ISO; 0 degrees s(-1)), and eccentric (ECC; -120, -60 degrees x s(-1)) contractions, electromyographic (EMG) activity of vastus lateralis (VL) and vastus medialis (VM) muscles were recorded before and after the exercise. Neural (M-wave) and contractile (isometric muscular twitch) parameters of quadriceps muscle were also analyzed using electrical stimulation techniques.
Oxygen uptake (VO2), minute ventilation (VE), and heart rate (HR) significantly increased (P < 0.01) during the 2-h by, respectively, 9.6%, 17.7%, and 12.7%, whereas pedaling rate significantly decreased (P < 0.01) by 21% (from 87 to 69 rpm). Reductions in muscular peak torque were quite similar during CON, ISO, and ECC contractions, ranging from 11 to 15%. M-wave duration significantly increased (P < 0.05) postexercise in both VL and VM, whereas maximal amplitude and total area decreased (VM: P < 0.05, VL: NS). Significant decreases in maximal twitch tension (P < 0.01), total area of mechanical response (P < 0.01), and maximal rate of twitch tension development (P < 0.05) were found postexercise.
A reduction in leg muscular capacity after prolonged cycling exercise resulted from both reduced neural input to the muscles and a failure of peripheral contractile mechanisms. Several hypothesis are proposed to explain a decrease in pedaling rate during the 2-h cycling with a constancy of power output and an increase in energy cost.
The aim of this study was to examine the effects of fatigue induced by a 65-km ultramarathon on the oxygen cost of running (Cr) and cycling (Ccycl). The day before and immediately after the race, a group of nine well-trained male subjects performed two submaximal 4-min exercise bouts: one cycling at a power corresponding to 1.5 W x kg(-1) body mass on an electromagnetically braked ergometer, and one running at 11 km x h(-1) on a flat asphalt roadway. Before oxygen cost determinations, the subjects performed 12 "ankle" jumps at a given frequency that was fixed by an electronic metronome (2.5 Hz). From the non-fatigued to the fatigued condition, there was a significant increase in minute ventilation for both running (P < 0.01) and cycling (P < 0.0001). Significant changes were also found in respiratory exchange ratio both for running (P = 0.01) and cycling (P < 0.0001). However, running and cycling differed in that Cycyc increased significantly by [mean (SD)] 24.2 (11.5)% (P < 0.001), suggesting an alteration of muscle efficiency, while Cr did not change with fatigue [186.8 (14.1) mlO2 x kg(-1) x km(-1) vs 186.8 (18.7) mlO2 x kg(-1) x km(-1)]. In addition, contact times during hopping increased significantly from 0.173 (0.019) ms to 0.194 (0.027) ms (P < 0.01). Analysis of the factors that determine Cr indicate that the subjects modified their movement pattern in order to decrease the mechanical cost of running in such long-term fatigue conditions.
This article traces the history of scientific and empirical interval training. Scientific research has shed some light on the choice of intensity, work duration and rest periods in so-called 'interval training'. Interval training involves repeated short to long bouts of rather high intensity exercise (equal or superior to maximal lactate steady-state velocity) interspersed with recovery periods (light exercise or rest). Interval training was first described by Reindell and Roskamm and was popularised in the 1950s by the Olympic champion, Emil Zatopek. Since then middle- and long- distance runners have used this technique to train at velocities close to their own specific competition velocity. In fact, trainers have used specific velocities from 800 to 5000m to calibrate interval training without taking into account physiological markers. However, outside of the competition season it seems better to refer to the velocities associated with particular physiological responses in the range from maximal lactate steady state to the absolute maximal velocity. The range of velocities used in a race must be taken into consideration, since even world records are not run at a constant pace.