Article

Effects of Postactivation Potentiation Warm-up in Male and Female Sport Performances: A Brief Review

December 2010
Strength & Conditioning Journal 32(6):58-64

Authors:

University of Hawaiʻi at Mānoa

A PROPER PRECOMPETITIVE WARM-UP DURING SPRINT COMPETITION WITH EXPLOSIVE ATHLETES WILL ELICIT A POSTACTIVATION POTENTIATION (PAP). THIS ARTICLE WILL REVIEW THE EFFECTS OF HEAVY PRELOAD WARM-UP PROTOCOLS ELICITING PAP WITH EXPLOSIVE MALE AND FEMALE ATHLETES, RESULTING IN ENHANCED PERFORMANCES AND PROVIDE STRENGTH COACHES WITH PRACTICAL APPLICATIONS.

Effect of different resistance increments during warm-up on the snatch performance of male weightlifters

Article

Full-text available

Jul 2024

This study investigated the effect of different resistance increments during warm-up on snatch performance of male weightlifters. Nine male college weightlifters were recruited. The 3 warm-up protocols were performed every 7 days with a randomized order: 1. Power snatch exercise with 10 % resistance increment (50 %, 60 %, 70 %, and 80 % of one-repetition maximum); 2. Power snatch exercise with 15 % resistance increment (50 %, 65 %, and 80 % of one-repetition maximum); 3. Self-selected resistance increment. Participants were tested based on 85 % maximum weight snatch after warm-up. Snatch performance was measured using peak vertical ground reaction force. Postural stability was measured using center-of-pressure displacement. Activation of seven shoulder, back, and leg muscles was measured using electromyography on the dominant side. In snatch performance, the 10 % increment protocol had a significantly higher peak vertical ground reaction force during the second-pull phase than the 15 % increment (d = 0.92, p < 0.05) and self-selected (d = 1.32, p < 0.05) protocols. In postural stability, no significant differences in center-of-pressure displacement among the three protocols were observed. For muscle activation, the 10 % increment protocol resulted in significantly higher activation of shoulder (d = 1.2–2.2, p < 0.05) during the second-pull phase than the other two protocols and higher activation of hip muscles (d = 1.73, p < 0.05) than self-selected protocol. To conclude, a warm-up protocol combining slow progression is preferable in improving power output during snatch in male weightlifters, probably through facilitating the activation of proximal limb muscles. It can enhance training quality while potentially reducing the risk of sports injuries.

Influence of Altitude and Environmental Temperature on Muscle Functional and Mechanical Activation After 30' Time Trial Run

Article

Full-text available

Dec 2019

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.

Maximal sprints within the warm-up does not affect pacing or performance in a 10 km cycle time trial

Article

Full-text available

May 2019

This study investigated the effects of the inclusion of a postactivation potentiation (PAP) specific warm-up (WU) consisting of all-out sprints on 10 kilometre cycling time trial (10 km-TT) pacing and performance. Following familiarization, thirteen well-trained male participants performed two 10 km cycle laboratory time trials following warm-ups that included either four 8 seconds (s) maximal sprints, or a matched total work performed at a constant exercise intensity. Power output (PO), heart rate (HR), and ratings of perceived exertion (RPE) were measured throughout and blood lactate (BLa) 3 minutes post exercise. There were no significant differences in total performance time, PO in any 2 km segment, RPE, or post-exercise BLa between conditions. Some significant differences (P<0.05) were observed in heart rate and cadence between 2 km segments. Addition of four all-out sprints to the WU did not improve 10 km time trial performance or alter pacing strategy displayed. This suggests that maximal sprinting in a warming up might not be an effective strategy to improve cycling time trial endurance performance.

Biomechanical Analysis of Unilateral Landings in Female Volleyball Athletes After a Dynamic and Combined Dynamic-Static Warm-Up

Thesis

Full-text available

May 2018

Jason Avedesian

My thesis research explored the biomechanical effect of warm-up strategies on landing mechanics in female volleyball athletes.

The Effects of Post-Activation Potentiation on Linear and Change-of-Direction Speed: Analysis of the Current Literature and Applications for the Strength and Conditioning Coach

Article

Full-text available

Feb 2017

This article investigates the current literature regarding post-activation potentiation (PAP) effects on linear and change-of-direction (COD) speed. The mechanisms behind PAP will be briefly described, as well as those factors that must be taken into consideration by the coach when they wish to implement a program that could invoke PAP. Linear and COD speed will be defined such that the coach knows what parameter they are training. Lastly, a review and meta-analysis of available literature regarding PAP and linear and COD speed will be conducted and discussed. Practical applications and conclusions from the analysis will be provided for the coach.

A Comparison of Acute Countermovement Jump Responses Following Functional Isometric and Dynamic Half Squats.

Article

Jun 2014

The purpose of this study was to compare acute CMJ responses following functional isometric (FI) and dynamic half (DH) squats. Ten strength-trained males (relative full back squat one repetition maximum (1RM): 1.9 ± 0.2) participated in a randomized crossover design study. On two separate days participants performed baseline CMJs followed by either FI or DH squats loaded with 150% of full back squat 1RM. Further CMJs were performed between 2 and 11 min after FI or DH squats. Kinematic and kinetic CMJ variables were measured. There were no differences observed between conditions when peak CMJ variables following FI or DH squats were compared to baseline values (p > 0.05). CMJ time effects (p < 0.05) were observed following squats. Increases in peak force (p < 0.05; FI: 3.9%, range: -0.9-9.1%; DH: 4.2%, range: 0.0-11.5%) and decreases in peak power (p < 0.05; FI: -0.4%, range: -5.1-4.0%; DH: -1.1%, range: -6.6-2.9%) occurred for combined condition data. Positive correlations between lower-body strength and the extent or timing of acute CMJ responses were not detected (p > 0.05). Due to the apparent lack of additive acute CMJ responses, the use of conventional DH squat protocols should be considered rather than FI squats in pre-competition and training situations. Furthermore, the establishment of individual FI and DH squat protocols also appears to be necessary, rather than relying on relative lower-body strength to predict the nature of acute CMJ responses.

Efficacy of Potentiation of Performance Through Over Weight Implement Throws On Male and Female Collegiate and Elite Weight Throwers

Article

Sep 2011
J STRENGTH COND RES

The purpose of this investigation was to determine the acute effects of 2 different overweight implements on weight throw performance. Seventeen collegiate and elite weight throwers were recruited to participate. A within-subject design was used to compare the difference between mean and peak distance after warm-up with a regulation weight (STAND), 1.37-kg overweight (OVRWGHT1), and 2.27-kg overweight implement (OVRWGHT2). Repeated-measures analysis of variance revealed a main effect for Treatment (p = 0.006) and a significant interaction effect for Treatment by Time (p = 0.041). The means for the OVRWGHT1 treatment (16.08 ± 2.5 m) and OVRWGHT2 (16.08 ± 2.7 m) were not different; however, the mean for STAND was significantly lower than that for the other treatments (15.58 ± 2.5, p < 0.02). Changes in performance between OVRWGHT treatments and STAND were found to correlate to one-repetition maximum (1RM) Power Clean (improvement for OVRWGHT 1, r = 0.536, p = 0.016; improvement for OVRWGHT2, r = 0.548, p = 0.014). The results suggest that in collegiate and elite athletes overweight implement warm-up may improve performance and that stronger athletes may be better suited to take advantage of this effect.

Acute Post-Activation Potentiation in NCAA Division II Female Athletes

Article

Jan 2014

Post-activation performance enhancement on change of direction speed: Effects of heavy back-squat exercise

Article

Jan 2024
SCI SPORT

Aims: The purpose of this study was to investigate the acute effects of a heavy back-squat exercise on change of direction performance. Methods: Eighteen male team sports athletes (age 23.6 ± 3.3y) performed T-test and 505 Test in consecutive sessions with and without heavy back-squat exercise applied as three sets of three repetitions at 90% of 1 RM as a conditioning activity in a randomized order. Change of direction tests were repeated at time intervals of 15 seconds, 2, 4, 8, 12 and 15 minutes after those two different conditions. Results: In 505 Test, no significant condition effect, time effect or condition–time interaction were found (P > 0.05). In T-test, there was no significant condition effect (P > 0.05); however, time effect and condition × time interaction were significant (P < 0.05). Conclusion: The findings of this study showed that the conditioning activity applied to elicit post-activation performance enhancement did not have any significant effect on 505 Test; on the contrary, in T-Test, the conditioning activity led to fatigue, rather than a potentiation effect.

Acute Post-Activation Potentiation Effects in NCAA Division II Female Athletes

Article

Full-text available

Jan 2014

International Journal of Exercise Science 7(3) : 212-219, 2014. Post-activation potentiation (PAP) is a phenomenon in which the power output of a muscle is immediately enhanced after heavy resistance exercise. Whereas the majority of PAP research has examined males, minimal research exists as to how female athletes respond. Therefore, the purpose of this study was to investigate the acute PAP response of back squats on static squat jump (SSJ) performance among NCAA Division II female athletes. Female athletes (n=29) who were current roster members from basketball, softball, and volleyball, performed 3 SSJ prior to 3 repetitions of the back squat exercise at 90% 1RM. After a 5-min rest, athletes once again performed 3 SSJ for maximal height, with peak power calculated using the Sayers equation. There was a significant interaction effect observed between time and team, p=0.022; post-hoc tests indicated that the volleyball team had a significant decrease in power, p=0.008. The main effect for time was not significant, p=0.279, indicating for the group as a whole, there was no evidence of a PAP response. The main effect for team was also nonsignificant, p=0.173, indicating no difference in power outputs by team. Strength and conditioning coaches who work with female athletes should be aware that the successful implementation of PAP complexes within this population appears to be highly individualized. Therefore, the use of PAP complexes in female athletes should consider both the absolute and relative strength of each athlete in conjunction with the length of the rest period when attempting to optimize the PAP response.

Post Activation Potentiation Effect of Different Preloading Protocols on Sprint Performance

Preprint

Full-text available

Oct 2024

This study aimed to investigate the post-activation potentiation effects of different pre-loading protocols involving blood flow-restricted plyometric jumps on sprint performance. In this randomized crossover experimental study, 15 athletes with at least seven years of sporting experience participated voluntarily. Participants underwent several anthropometric measurements (height, body weight, body mass index, and body fat percentage) as well as performance measurements (10-meter and 20-meter sprints). The data were analyzed using the SPSS statistical software. The effect size and percentage changes are reported to illustrate the practical significance of the differences. Cohen's d test was used to determine the effect size. Differences between repeated measures data were analyzed using repeated-measures one-way ANOVA. Tukey’s post hoc test was used to determine the protocols responsible for the differences. The eta-squared (η²) value was used to express the effect size. The significance level was set at p=0.05, with 95% confidence interval. In conclusion, all pre-loading protocols demonstrated a positive post-activation potentiation effect on sprint performance. However, the greatest potentiating effect was observed with the pre-loading protocol involving blood flow-restricted plyometric jumps with a weighted vest.

Optimizing post-activation performance enhancement in athletic tasks: A systematic review with meta-analysis for prescription variables and research methods

Article

Dec 2024
SPORTS MED

Background. Post-activation performance enhancement (PAPE) has demonstrated efficacy in acutely improving athletic performance. However, its distinction from general warm-up (GW) effects remains ambiguous and experimental designs adopted in most PAPE studies exhibit important limitations. Objectives. To i) examine the effects of research methodology on PAPE outcomes, ii) explore PAPE outcomes in relation to comparison methods, performance measures, GW comprehensiveness, recovery duration, participants’ characteristics, conditioning activity (CA) parameters, and iii) make recommendations for future PAPE experimental designs based on the results of the meta-analysis. Methods. Four databases were searched for peer-reviewed English-language literature. Risk of bias was assessed using a modified Cochrane Collaboration’s tool and PEDro scale. PAPE groups were compared with control groups, pre-conditioning activity (pre-CA) performances were compared to post-conditioning activity (post-CA) performances throughout a verification test in PAPE groups, and control groups were compared before and after the ‘rest’ period using a three-level meta-analysis. Further analyses including subgroup analysis and both linear and nonlinear meta-regression methods were used to explore the effect of different moderating factors on PAPE magnitude. A subgroup analysis of GW comprehensiveness was conducted using four classification methods. One method classified GW as non-comprehensive (stretching or jogging only), partially comprehensive (stretching, jogging, and low-intensity self-weighted dynamic exercises), and comprehensive (adding maximal or near-maximal intensity CAs to a partially comprehensive GW). The other three classifications were adjusted according to the type and number of GW exercises. Certainty of evidence was assessed using the GRADE approach. Results. Final analysis included 62 PAPE studies (1,039 participants, male: n = 857, female: n = 182) with high risk of bias and low certainty of pooled evidence. A trivial PAPE effect was observed from pre- to post-CA (effect size [ES] = 0.12, 95%CI [0.06 to 0.19], prediction intervals [PI] = -0.29 to 0.54); a small PAPE effect was observed when compared to a control group (ES = 0.30, 95%CI [0.20 to 0.40], PI [-0.38 to 0.97]). The slightly greater effect against control resulted from a small decrease in performance in control groups (ES = -0.08, 95%CI [-0.13 to -0.03], PI [ -0.30 to 0.14]), but there was no relationship with between PAPE recovery time (β = -0.005, p = 0.149). Subgroup analyses showed that PAPE magnitude was greater for non-comprehensive GWs (ES = 0.16) than comprehensive (ES = 0.01) and partially comprehensive GWs (ES = 0.11). In contrast, the control group showed a decline in performance after comprehensive GW (ES = -0.20). An inverted U-shaped PAPE was noted as a function of recovery time. In some cases, PAPE appeared to manifest at <1min post CA. Additionally, participants with longer training experience (ES = 0.36) and higher training levels (ES = 0.38) had larger PAPE magnitudes. PAPE effect was higher in females (ES = 0.51) than males (ES = 0.32) and mixed groups (ES = 0.16) but did not reach a significant difference (p > 0.05). Plyometric exercise (ES = 0.42) induced greater PAPE amplitude than traditional resistance exercise (ES = 0.23), maximal isometric voluntary contraction (ES = 0.31) and other CA types (ES = 0.24). Conclusions. Although the overall pooled results for both PAPE pre- vs. post-CA and PAPE vs. control group comparisons showed significant improvement, the wider and past-zero prediction intervals indicate that future studies are still likely to produce negative results. The comprehensiveness of the GW, the time between GW and the pre-CA test, participant sex, training level, training experience, type of CA, number of CA sets, and recovery time after CA all influence the PAPE magnitude. The PAPE magnitude was trivial after comprehensive GW, but it was greater in studies with a control group (i.e. no CA) because performance decreased over the control period, inflating the PAPE effect. Finally, two theoretical models of PAPE experimental design and suggestions for methodological issues are subsequently presented. Future studies can build on this to further explore the effects of PAPE.

Acute responses to a potentiation warm-up protocol on sprint and change of direction in female football players: a randomized controlled study

Article

Full-text available

Nov 2024

Objectives To evaluate the acute effect of exposure to a potentiation warm-up protocol compared to a usual warm-up program. Design Randomized parallel control trial. Setting Synthetic grass in the club’s facilities (Portugal). Participants Seventeen female football players (age: 23.9 ± 3.9 years), were randomly allocated to a control (n = 8) and an experimental group (n = 9). To allocate the players, a table was computer-generated by a research team member with no involvement in the trial. Intervention The control group performed their usual warm-up program, while the experimental group performed a potentiation warm-up protocol with jumps combined with sprints with change of direction. Main outcomes measures The players were tested pre- and post-intervention for a 40-m linear sprint and pre-planned change of direction using the T-test. Statistical analysis An intention-to-treat analysis was performed, with all the participants originally randomized being involved. The normal distribution was verified by the Shapiro-Wilk test. The assumption of sphericity was analyzed. Effect sizes were calculated using partial eta squared. Results No significant pre-post differences in the T-test and in the 40-m sprint were detected for any group. However, in the T-test, large effect sizes in time increments were observed within the experimental (0.27 s; p > 0.05, ηp² = 0.176) and control groups (0.06 s; p > 0.05, ηp² = 0.176). Also, in the 40-m sprint, large effect sizes in time increments were observed within the experimental (0.05 s; p > 0.05, ηp² = 0.251) and control groups (0.09 s; p > 0.05, ηp² = 0.251). Conclusions The performance-enhancing ability of the potentiation method performed at warm-up was not verified when applied to female football players. Thus, the potentiation methods may not improve sprint and COD ability for this population. However, the lack of statistical significance may have been due to reduced statistical power, as three of four effects suggest acute performance impairment after a supposed potentiation-oriented warm-up. Nevertheless, the presence of a statistical type 2 error cannot be ruled out. Registration number (retrospectively registered) NCT06555185; Project URL: https://clinicaltrials.gov/study/NCT06555185.

Enhancing team sports performance: a case study of the optimal post-warm-up time window

Article

Full-text available

Aug 2024
Sport Sci Health

Warm-up routines are crucial for performance enhancement in team sports, with their effectiveness varying based on individual profiles, exercise mode and timing relative to the activity. This study investigates the impact of a 5–10 min interval post-warm-up on physical performance and sympathetic stimulus, as indicated by salivary biomarkers, in 19 college athletes. Performance was assessed via countermovement jump, 20 m sprint and handgrip strength tests conducted pre-warm-up, 5 min post-warm-up and 10 min post-warm-up. Saliva samples were collected at each stage to evaluate flux, α-amylase activity and protein content. Significant effects (p < .001) were observed in all three performance measures and saliva markers. Notably, sprint performance showed the greatest enhancement at the 5 min mark post-warm-up, while jumping improvements persisted through the 10 min window. However, a slight decline in sprint ability was observed from 5 to 10 min post-warm-up. These findings underscore the importance of optimizing warm-up timing and eventually considering re-warm-up strategies to maximize acute performance in team sports.

Effects of low-intensity warm-up associated with blood flow restriction: A study protocol for a randomized controlled clinical trial

Preprint

Full-text available

Jul 2023

Introduction: Warm-up has the function of preparing the body structures for a given task to be performed during sports, increasing body and muscle temperature, focused on improving performance. Therefore, the use of the blood flow restriction technique (BFR) can be seen as a promising alternative for promoting greater mechanical and muscular stress, thus providing a more efficient warm-up and optimizing performance. Objectives: to analyze the effects of RFS used during low-intensity warm-up compared with low-intensity and high-intensity warm-up without RFS on performance, skin surface temperature, and perceptual and muscular outcomes. Methods: a randomized controlled clinical trial will be carried out, with 33 amateur soccer players aged between 18 and 35 years who will be randomly divided into three groups: low intensity warm-up without BFR (30% VO2peak), high intensity warm-up without BFR (80% VO2peak) and low-intensity warm-up associated with BFR (80% of total occlusion pressure) [30% VO2peak-BFR]. All groups will carry out the warm-up protocol and the outcomes will be evaluated at baseline and immediately after the end of the warm-up, as well as 10 and 20 minutes after its completion, which are sequentially: skin surface temperature through thermography; tone, stiffness and muscle elasticity by myotometry, subjective perception of pain by analogue pain scale (VAS); pain threshold through the pressure algometer; subjective perception of exertion by the Borg scale; perception of discomfort in relation to BFR on the Likert-10 scale; 30 meter sprints measured through photocells and vertical jump measured through the force platform. Descriptive statistics will be used and comparisons will be made using the generalized linear mixed model, assuming a significance level of p<0.05. Discussion: the clinical applicability of this study, if its hypothesis is confirmed, will have as its main focus the performance gain of amateur athletes, preparing them for the game subsequent to the warm-up period, and may also be extended to sports with similar demands, due to the BFR technique being easy to apply and access. Furthermore, BFR during warm-up can also be incorporated within training centers and not just in pre-game moments. Trial registration number: ClinicalTrials.gov, NCT05523674. Registered on 08 November 2022.

Acute effect of a conditioning activity on vertical jump height in trained adult women: a systematic review with meta-analysis

Article

Full-text available

Sep 2023

Objective: To verify the acute effect of conditioning activity protocols on vertical jump height in trained women. Methods: A systematic review with meta-analysis was performed based on studies retrieved from Pubmed, SciELO, Scopus, SPORTDiscus, and Web of Science databases. The screening and eligibility of the studies were carried out by two independent evaluators and with a third researcher in case of disagreements. The result of the meta-analysis was obtained from the standardized mean difference (SMD), 95% confidence intervals (CI), and inconsistency test (I2). Results: Five studies were included in the meta-analysis. The conditioning activity intervention generated higher jumping performances than the control group/session (SMD = 0.91 [95% CI: 0.57 - 1.24]), but with high heterogeneity (I2 = 75%). Subgroup analysis demonstrated that dynamic conditioning activities have better jump performance responses than isometrics. Conditioning activities with multiple sets increased jump performance more than single sets. Female athletes and those with more training experience appear more responsive to conditioning activity than females with lower training levels. Conclusion: A conditioning activity can improve the vertical jump’s acute performance in trained women. Female athletes with more training experience seem more responsive to dynamic conditioning activity, with greater volume and intensities above 70% of 1RM.

How to activate the glutes best? Peak muscle activity of acceleration-specific pre-activation and traditional strength training exercises

Preprint

Mar 2023

ABSTRACT. Isometric training and pre-activation are proven to enhance acceleration performance. However, traditional strength training exercises do not mirror the acceleration-specific activation patterns of the gluteal muscles, characterized by ipsilateral hip extension during contralateral hip flexion. Therefore, peak electromyographic activity of two acceleration-specific exercises was investigated and compared to two traditional strength training exercises each for the M. gluteus maximus (GMAX) and medius (GMED). Twenty-four participants from various athletic backgrounds (13 males, 11 females, 26 years, 178 cm, 77 kg) performed four GMAX (half-kneeling glute squeeze (HKGS), resisted knee split (RKS), hip thrust (HT), split squat (SS)) and four GMED (resisted abduction in prone position (RAPP), isometric clam (IC), side-plank with leg abduction (SP), resisted side-stepping (RSS)) exercises in a randomized order. No significant differences (p>0.05) were found between the HT, RKS and HKGS. The RKS (p=0.011, d=0.96) and the HKGS (p=0.064, d=0.68) elicited higher peak activity than the SS with large and moderate effects, respectively. The RAPP elicited significantly higher GMED activity with large effect compared to RSS (p<0.001, d=1.41) and moderate effect concerning the SP(p=0.002, d=0.78). Consequently, the acceleration-specific exercises effectively activate the gluteal muscles for pre-activation and strength training purposes to improve horizontal acceleration.

Reduced isometric knee extensor force following anodal transcranial direct current stimulation of the ipsilateral motor cortex

Article

Full-text available

Jan 2023
PLOS ONE

Background The goal of this study was to determine if 10-min of anodal transcranial direct current stimulation (a-tDCS) to the motor cortex (M1) is capable of modulating quadriceps isometric maximal voluntary contraction (MVC) force or fatigue endurance contralateral or ipsilateral to the stimulation site. Methods In a randomized, cross-over design, 16 (8 females) individuals underwent two sessions of a-tDCS and two sham tDCS (s-tDCS) sessions targeting the left M1 (all participants were right limb dominant), with testing of either the left (ipsilateral) or right (contralateral) quadriceps. Knee extensor (KE) MVC force was recorded prior to and following the a-tDCS and s-tDCS protocols. Additionally, a repetitive MVC fatiguing protocol (12 MVCs with work-rest ratio of 5:10-s) was completed following each tDCS protocol. Results There was a significant interaction effect for stimulation condition x leg tested x time [F(1,60) = 7.156, p = 0.010, ηp² = 0.11], which revealed a significant absolute KE MVC force reduction in the contralateral leg following s-tDCS (p < 0.001, d = 1.2) and in the ipsilateral leg following a-tDCS (p < 0.001, d = 1.09). A significant interaction effect for condition x leg tested [F(1,56) = 8.12, p = 0.006, ηp² = 0.13], showed a significantly lower ipsilateral quadriceps (to tDCS) relative MVC force with a-tDCS, versus s-tDCS [t(15) = -3.07, p = 0.016, d = -0.77]. There was no significant difference between the relative contralateral quadriceps (to tDCS) MVC force for a-tDCS and s-tDCS. Although there was an overall significant [F(1,56) = 8.36, p < 0.001] 12.1% force decrease between the first and twelfth MVC repetitions, there were no significant main or interaction effects for fatigue index force. Conclusion a-tDCS may be ineffective at increasing maximal force or endurance and instead may be detrimental to quadriceps force production.

The Acute Effects of Weighted Vest Protocols on 20-Metre Sprint Performance in Youth Soccer Players

Article

Full-text available

May 2022

This investigation examined the effects of a warm-up containing weighted vest (WV) sprints on subsequent 20-metre sprint time relative to a control (C) condition in youth soccer players (n=12, mean ± SD age 16 ± 0.60 years, height 175.17 ± 5.92 cm and body mass 61.85 ± 5.88 kg). The main experimental trials consisted of three WV conditions at 10, 20 and 30% of body mass (WV10, WV20 and WV30) and C. Participants were required to complete one 20-metre sprint with each of WV conditions or without additional mass as part of C prior to a 20-metre sprint at 4-, 8- and 12-minutes. A two-way repeated measures ANOVA revealed no significant difference between any of the conditions and rest periods (p = >0.05). The between condition effect sizes for 20-metre sprint times were moderate at 4- and 12-minutes post WV10 (d = -0.86 and -1.15, respectively) and 12-minutes post WV20 (d = -0.84) and WV30 (d = -0.80). Moderate effect sizes were also observed at 4-minutes post WV10 (d = -1.04) and WV20 (d = -0.67) for 10-metre sprint times. These findings demonstrate that WV loading has no significant effect on 20-metre sprint time in youth soccer players. However, there is an opportunity for S&C coaches to implement WV warm-ups of no more than 30% body mass to improve 20-metre sprint times.

Optimal Velocity Loss Threshold for Inducing Post Activation Potentiation in Track and Field Athletes

Article

Full-text available

May 2022

The aim of this study was to determine the optimal velocity loss (VL) threshold that maximises the post activation potentiation (PAP) stimulus for achieving larger and more consistent performance gains in track and field athletes. Twenty-two athletes from athletics participated in four back squat PAP tests with four different VL threshold (5%, 10%, 15% and 20% VL) at an intensity of 85% 1RM. Countermovement jump (CMJ) height, power, and momentum were assessed before, and 10s, 4, 8, 12, 16 minutes after the PAP condition. Repetitions of the squat in all the PAP conditions were also recorded. Only the 5% VL condition produced significant improvements in height (ES=0.73, P=0.038), peak power output (ES=0.73, P=0.038) and momentum (ES=0.72, P=0.041) of CMJ, and these changes appeared 8 minutes after the condition. The total number of repetitions during the 5% VL condition was significantly lower than that observed in the 15% (P=0.003) and 20% VL (P＜0.001) trials. The results from this study indicate that 5%VL during the 2 sets preconditioning squat at 85%1RM was optimal for eliciting PAP in a CMJ exercise, and resulted in significant increases at the 8-min recovery period. The same squat condition also had the least number of repetitions. However, considering the efficiency in practice, athletes can also choose the rest time of 4-min, which can also achieve similar results.

Post-Activation Performance Enhancement in Sprinters: Effects of Hard Versus Sand Surfaces

Article

Full-text available

Dec 2021

This study aimed to compare the post-activation performance enhancement induced by successive drop-jumps performed on hard or sand surfaces in the sprint and jump performance of top-level sprinters. Athletes were tested on 2 occasions. On each visit they were allocated to one of the experimental protocols, which consisted of performing 2x5 drop-jumps from a box height of 60 cm on hard or sand surfaces in a randomized order, 7 days apart. Prior to and 7 and 15 minutes after executing the drop-jumps, the sprinters performed countermovement jumps and 60-m sprint tests. Differences between sprinting splits and surfaces were assessed using a two-way analysis of variance with repeated measures. No significant differences in jump height or sprint time were observed (P> 0.05), regardless of the surface used (i.e., hard or sand) during the conditioning activity (effect sizes [95% confidence intervals] ranging from 0.01 [-0.84; 0.84] to 0.44 [-0.42; 1.27]). Performing drop-jumps on sand or hard surfaces immediately before maximum sprinting bouts does not provide any additional benefit to top-level sprinters. Sprint coaches may prescribe short-plyometric training activities on sand surfaces even close to competitions, bearing in mind that this strategy will not compromise sprint-specific performance.

Low-energy laser therapy application on knee joints as an auxiliary treatment in patients with polyarticular juvenile idiopathic arthritis: a dual-arm randomized clinical trial

Article

Full-text available

Oct 2021
LASER MED SCI

Patients with juvenile idiopathic arthritis (JIA) always experience persistent pain and stiffness which induces muscle weakness, fatigue, and functional limitations. This study evaluated whether applying low-energy laser therapy (LLT) on the knee joint could be an effective adjuvant intervention for patients with JIA. Sixty children with polyarticular JIA participated and were randomly allocated to receive either LLT (wavelength λ = 903 nm; power output of 50 mW; and energy of 1.5 J) plus exercises (LLT group) or exercises alone (control group). Pain, peak concentric torque of quadriceps muscles, fatigue, and functional status were measured by the visual analogue scale, isokinetic testing system, Pediatric Quality of Life Inventory Multidimensional Fatigue Scale, and Childhood Health Assessment Questionnaire, respectively pre- and post-intervention, and at 6-month follow-up. Per the mixed-model analysis of variance, the LLT group showed a statistically more favorable improvement in pain (P = .003, ηp2 = .014), fatigue perception (P = .004, ηp2 = .015), and functional status (P = .022, ηp2 = .09) across the three assessment occasions, as compared to the control group. However, no significant difference was demonstrated between both groups concerning peak concentric torque (all P > .05). Incorporation of LLT into the standard physical rehabilitation program for patients with JIA has the potential to induce more conducive improvements in pain, fatigue, and functional performance, but is not effective for improving muscle performance.

Warm-Up Intensity and Time Course Effects on Jump Performance

Article

Full-text available

Nov 2020
J SPORT SCI MED

Jump performance is affected by warm-up intensity and body temperature, but the time course effects have not been thoroughly investigated. The purpose of this study was to investigate time course effects on jump performance after warm-up at different intensities. Nine male athletes (age: 20.9 ± 1.0 years; height: 1.75 ± 0.03 m; weight: 66.4 ± 6.3 kg; mean ± SD) volunteered for this study. The participants performed three warm-ups at different intensities: 15 min at 80% VO2 max, 15 min at 60% VO2 max, and no warm-up (control). After each warm-up, counter movement jump (CMJ) height, vastus lateralis temperature, heart rate and subjective fatigue level were measured at three intervals: immediately after warm-up, 10 min after, and 20 min after, respectively. Significant main effects and interactions were found for muscle temperature (intensity: p < 0.01, η2p = 0.909; time: p < 0.01, η2p = 0.898; interaction: p < 0.01, η2p = 0.917). There was a significant increase of muscle temperature from the baseline after warm-up, which lasted for 20 min after warm-up with 80% VO2 max and 60% VO2 max (p < 0.01). Muscle temperature was significantly higher with warm-up at 80% VO2 max than other conditions (P < 0.01). Significant main effects and interactions for CMJ height were found (intensity: p < 0.01, η2p = 0.762; time: p < 0.01, η2p = 0.810; interaction: p < 0.01, η2p = 0.696). Compared with the control conditions, CMJ height after 80% VO2 max and 60% VO2 max warm-ups were significantly higher (p < 0.01 and p < 0.05, respectively). CMJ height at 20 min after warm-up was significantly higher for 80% VO2 max warm-up than for 60% VO2 max warm-up (p < 0.01). However, CMJ height at 10 min after 60% VO2 max warm-up was not significantly different from the baseline (p < 0.05). These results showed that both high and moderate intensity warm-up can maintain an increase in muscle temperature for 20 min. Jump performance after high-intensity warm-up was increased for 20 min compared to a moderate intensity warm-up.

The Immediate Effect of Spinal Manipulation on Ball Velocity and Neuromuscular Function During an Instep Kick in Former Varsity Soccer Players: A Feasibility Study

Article

Aug 2020

Corso, M, Liang, L, Tran, S, Howitt, S, Srbely, J, and Mior, SA. The immediate effect of spinal manipulation on ball velocity and neuromuscular function during an instep kick in former Varsity soccer players: a feasibility study. J Strength Cond Res XX(X): 000-000, 2020-Spinal manipulation (SM) has been shown to increase ball velocity (BV) in soccer players. Evidence suggests that SM modulates responses at spinal or cortical levels to enhance force production in asymptomatic populations. No studies have explored the underlying neuromuscular mechanisms contributing to changes in BV post-SM in soccer players. We assessed the feasibility of measuring change in BV and neuromuscular function after SM in former Varsity level soccer players with a pre-post study design. Three to 5 maximal instep kicks were performed before and after SM at the L3-5 level. Ball velocity was measured using high-speed camera. Activation of lower limb and trunk musculature was recorded with electromyography. Outcomes included ease of recruitment, scheduling and data capture, as well as expectation and perception of SM effect and adverse events (AE). Fifteen potential subjects were recruited over 1.5 months. Eleven were scheduled (24-31 years; 8 females, 3 males). Two subjects reported mild AE after maximal voluntary isometric contraction testing. A significant increase in BV (mean change: 1.75 m·s [95% confidence interval: 0.5-3.0]) and a trend to increased peak-activation of knee extensors (90.7%) were observed post-SM. Findings suggest that our recruitment strategy and methodology are feasible in a larger trial with some modifications. Our preliminary findings support previous research by suggesting that increased BV may be mediated through increased activation of knee extensors during the kick. Our findings may offer additional insight into the underlying neuromuscular mechanisms contributing to immediate change in BV post-SM.

170270-Texto do artigo-409816-1-10-20200529

Article

Full-text available

Jul 2020

Protocolos de activación y su efecto en la performance deportiva en nadadores recreativos de Viña del Mar Resumen El objetivo del presente estudio fue determinar los efectos de tres protocolos de activación muscular en la fuerza y tiempo en una prueba de 25 metros de estilo libre con salida baja en un grupo de nadadores de nivel recreativo de Viña del Mar, Chile. Participaron del estudio 31 sujetos, con una edad promedio de 21,86 ± 2,38 años. Estos fueron divididos en cuatro grupos de participación en base a un método cruzado aleatorio, los grupos se clasificaron en: grupo control (CON), grupo de ejercicio isométrico (ISO), grupo de ejercicios excéntricos y concéntricos (EX-CON) y grupo de movilidad articular (MA). En todos los protocolos se utilizó una carga de entrenamiento equivalente al peso corporal del sujeto. Las variables evaluadas fueron; tiempo en segundos en 25 metros estilo libre con salida baja y fuerza máxima registrada a través del monitor de fuerza modelo FMON-1 de la marca ART-OFICIO®. Los resultados evidenciaron que la activación con isometría (ISO) tuvo respuesta positiva (p = 0,020) en la variable fuerza (N). Los protocolos de entrada en calor no produjeron disminución del tiempo en la prueba de 25 metros (p > 0,05). Estos resultados llevan a la conclusión que la isometría aumento la fuerza en el agua, pero este aumento en la fuerza no reflejó una disminución del tiempo obtenido en el sprint de natación, los demás protocolos no produjeron variación en el tiempo ni en la fuerza, se sugiere seguir explorando los beneficios de una activación previa a un esfuerzo deportivo, y en particular indagar los beneficios de diferentes protocolos de potenciación post activación como intervención previa a pruebas de sprint en natación. Palabras clave: Natación; Activación; Rendimiento; Fuerza. Introducción Diversos estudios han evidenciado efectos positivos inducidos por la activación previa a la competencia deportiva 1-2 , los profesionales y entrenadores deben considerar el uso de la potenciación con una activación que no produzca efectos negativos en la rigidez del tendón 3 para no perjudicar el rendimiento en el deportista, se ha visto en modelos animales que el entrenamiento disminuye la rigidez del tendón y aumenta el metabolismo del colágeno 4 , es por esto que los deportistas tienen tendones con capacidad para soportar grandes cargas como las producidas por la potenciación post activación (desde ahora PAP), en cambio, sujetos que practican deporte de manera recreativa no presentan esta misma adaptación, esto condicionaría la aplicación de protocolos de PAP sin carga en deportistas de nivel recreativo ya que una activación con una carga elevada puede producir lesión o disminución del rendimiento deportivo 5. El uso de los protocolos de activación muscular en los últimos años se ha popularizado, este interés se

Protocolos de activación y su efecto en la performance deportiva en nadadores recreativos de Viña del Mar

Article

Full-text available

Apr 2019

El objetivo del presente estudio fue determinar los efectos de tres protocolos de activación muscular en la fuerza y tiempo en una prueba de 25 metros de estilo libre con salida baja en un grupo de nadadores de nivel recreativo de Viña del Mar, Chile. Participaron del estudio 31 sujetos, con una edad promedio de 21,86 ± 2,38 años. Estos fueron divididos en cuatro grupos de participación en base a un método cruzado aleatorio, los grupos se clasificaron en: grupo control (CON), grupo de ejercicio isométrico (ISO), grupo de ejercicios excéntricos y concéntricos (EX – CON) y grupo de movilidad articular (MA). En todos los protocolos se utilizó una carga de entrenamiento equivalente al peso corporal del sujeto. Las variables evaluadas fueron; tiempo en segundos en 25 metros estilo libre con salida baja y fuerza máxima registrada a través del monitorde fuerza modelo FMON-1 de la marca ART-OFICIO®. Los resultados evidenciaron que la activación con isometría (ISO) tuvo respuesta positiva (p = 0,020) en la variable fuerza (N). Los protocolos de entrada en calor no produjeron disminución del tiempo en la prueba de 25 metros (p > 0,05). Estos resultados llevan a la conclusión que la isometría aumento la fuerza en el agua, pero este aumento en la fuerza no reflejó una disminución del tiempo obtenido en el sprint de natación, los demás protocolos no produjeron variación en el tiempo ni en la fuerza, se sugiere seguir explorando los beneficios de una activación previa a un esfuerzo deportivo, y en particular indagar los beneficios de diferentes protocolos de potenciación post activación como intervención previa a pruebas de sprint en natación.

Effects of heavy barbell hip thrust vs back squat on subsequent sprint performance in rugby players

Article

Full-text available

Jul 2020

The objective of this research was to compare the effect of Post-Activation Performance Enhancement (PAPE) exerted on the back squat (BS) versus the barbell hip thrust (HT) on the sprint performance (5- and 10-m). 17 male amateur rugby players participated in the study (age 22.14 ± 2.52 years; body mass 81.06 ± 9.6 kg; height 1.78 ± 0.05 m). All participants performed a dynamic maximum strength test (3RM) in BS and HT at maximum speed. Two randomized sessions were performed inducing PAPE using BS or HT trough three series with three repetitions at 85% 1RM eight minutes before the sprint tests. An ANOVA of repeated measurement, found no differences in the time for 5-m (F = 0.398, P = 0.537, η2p = 0.024) or 10-m (F = 2.589, P = 0.127, η2p = 0.139). There were no significant differences in the Protocol effect between HT and BS in 5-m or 10-m (F = 2.963, P = 0.104, η2p = 0.156 and F = 1.472, P = 0.243 η2p = 0.084, respectively). There were also no differences in the Time x Protocol interaction at 5-m (F = 0.001, P = 0.976, η2p

O aquecimento como prática saudável para o exercício

Chapter

Full-text available

Jan 2018

Eccentric flywheel post-activation potentiation influences swimming start performance kinetics

Article

Full-text available

Aug 2018
J SPORT SCI

This study aimed to assess the effects of post-activation potentiation in the strength related variables of a kick start. Thirteen competitive swimmers performed three kick starts after a standardized warm up (denoted USUAL) and another after inducing post-activation through five isotonic repetitions on an eccentric flywheel (denoted PAP). A T-test was used to quantify differences between USUAL and PAP warm up. The best trial of each subject achieved by natural conditions (denoted PEAK) was compared with data obtained after PAP. An instrumented starting block with independent triaxial force plates, collected the strength variables related with the impulse at take off. Improvements in the vertical components of force were observed after PAP compared with USUAL, meanwhile no differences were detected on the horizontal components of it. The velocity at take off was higher after PAP compared with the USUAL (4.32 ± 0.88 vs 3.93 ± 0.60 m*s-1; p = 0.02). No differences in force or velocity were detected comparing PAP with PEAK (4.13 ± 0.62 m*s-1, p = 0.11). The PAP warm-up increased vertical force and it was transferred to a higher resultant velocity at take-off. This improvement would equal the best result possible obtained in natural conditions after some trials. KEY WORDS: Warm-Up; Pre-Activation; YoYo Squat; Force Impulse

The General Adaptation Syndrome: A Foundation for the Concept of Periodization

Article

Full-text available

Apr 2018
SPORTS MED

Recent reviews have attempted to refute the efficacy of applying Selye’s general adaptation syndrome (GAS) as a conceptual framework for the training process. Furthermore, the criticisms involved are regularly used as the basis for arguments against the periodization of training. However, these perspectives fail to consider the entirety of Selye’s work, the evolution of his model, and the broad applications he proposed. While it is reasonable to critically evaluate any paradigm, critics of the GAS have yet to dismantle the link between stress and adaptation. Disturbance to the state of an organism is the driving force for biological adaptation, which is the central thesis of the GAS model and the primary basis for its application to the athlete’s training process. Despite its imprecisions, the GAS has proven to be an instructive framework for understanding the mechanistic process of providing a training stimulus to induce specific adaptations that result in functional enhancements. Pioneers of modern periodization have used the GAS as a framework for the management of stress and fatigue to direct adaptation during sports training. Updates to the periodization concept have retained its founding constructs while explicitly calling for scientifically based, evidence-driven practice suited to the individual. Thus, the purpose of this review is to provide greater clarity on how the GAS serves as an appropriate mechanistic model to conceptualize the periodization of training.

İzometrik Önkondisyonlanma Kontraksiyonunun Sıçrama Performansına Akut Etkileri

Article

Full-text available

Dec 2017

Bir kas grubunun istemli ya da elektriksel uyarılı kontraksiyonlara verdiği yanıt ve performansı, o kas grubunun kontraktil geçmişinden pozitif veya negatif etkilenmektedir. Bir kas grubunun performansı kontraktil geçmişindeki tekrarlı kontraksiyonlar sonucu yorgunluk nedenli düşüş gösterebilir ya da potansiyalizasyon etkili birkaç tekrar maksimal veya maksimale yakın önkondisyonlanma kontraksiyonu sonrası artış gösterebilir. Bu çalışmanın amacı, standart bir ısınma sonrası uygulanan ve izometrik bacak itme egzersizi içeren bir önkondisyonlanma kontraksiyonunun, skuat ve aktif sıçrama performansına akut etkilerini incelemektir. Yirmi (7 kadın, 13 erkek) Spor Bilimleri Fakültesi öğrencisi (yaş; 22,1±2,07 yıl, boy; 173,5±8,7 cm, vücut ağırlığı; 68,9±10,2 kg, vücut yağ yüzdesi; % 16,5±5,84) bu çalışmaya gönüllü olarak katılmıştır. Bu çalışmada öntest-sontest araştırma modeli kullanılmış ve katılımcılar önkondisyonlanma kontraksiyonunundan önce ve sonra skuat ve aktif sıçrama testlerine katılmışlardır. Önkondisyonlanma kontraksiyonu, oturarak bacak itme egzersiz aletinde (135o diz fleksiyon), 5 sn süreli maksimal istemli izometrik kasılma şeklinde ve 90 sn dinlenme aralıklarından oluşan 3 maksimal tekrarlı bir set şeklinde uygulanmıştır. Bu 3 maksimal tekrar sonrası 8 dk pasif dinlenme verilmiş ve ardından sıçrama testleri yapılmıştır. Skuat ve aktif sıçrama öntest-sontest değerleri arasında fark olup olmadığını belirlemek için ise Eşleştirilmiş Örneklem T-testi kullanılmıştır. İstatistiksel analizler, hem skuat (p=0,13), hem de aktif sıçrama (p=0,83) öntest ve sontest değerleri arasında istatistiksel olarak anlamlı fark olmadığını göstermiştir. Sonuçlara göre önkondisyonlanma kontraksiyonundan hemen önce ve önkondisyonlanma kontraksiyonundan 8 dk sonra ölçülen skuat ve aktif sıçrama yükseklikleri arasında bir fark yoktur. Bu çalışmada uygulanan önkondisyonlanma kontraksiyonu sonucunda, skuat ve aktif sıçrama performanslarında akut artış görülmemiştir. Bu sonuçlara göre, bu önkondisyonlanma kontraksiyonu protokolünün sıçrama performansını geliştirmediği anlaşılmıştır. Anahtar Kelimeler: Aktivite öncesi kontraksiyon, ön yükleme, post aktivasyon potansiyalizasyonu, patlayıcı güç, kompleks antrenman ABSTRACT Performance and response of a muscle group to voluntary or electrically induced contraction are positively or negatively affected by its contractile history. The performance of a muscle can decrease after continuous contractions under the exhaustive influence of contractile history or can increase after potentiation-induced a couple of maximal or close to maximal preconditioning contractions. The aim of this study was to investigate acute effects of preconditioning contraction during isometric leg press followed by a standard warm-up on squat and countermovement jump heights. Twenty (7 female, 13 male) sport sciences faculty students (age; 22.1±2.07 years, height; 173.5±8.7 cm, weight; 68.9±10.2 kg, body fat percentage; 16.5±5.84 %) participated in this study. Pretest-posttest study design was used in this study and subjects completed squat and countermovement jump test before and after preconditioning contraction. Preconditioning contraction was performed on a seated leg press machine (knee flexion 135o) maximal isometric voluntary contraction for 5 s. Preconditioning contraction was performed with 3 maximal repetitions and 90 s rest intervals, after this 3 maximum repetitions 8 min passive recovery was given and then jump tests were performed. A paired sample T-test was used to determine differences between pretest and posttest values of squat and countermovement jump. Statistical analysis showed that no statistically significant differences between pre and post test for squat (p=0.13) and countermovement jump (P=0.83). According to the results, there are no differences between squat and countermovement jumping heights measured before preconditioning contraction and 8 min after preconditioning contraction. As a result of the preconditioning contraction applied in this research, acute increase was not found in squat and countermovement jumping performances. According to these results, it was concluded that this preconditioning contraction protocol did not increase jumping performance.

Postactivation Potentiation: Sometimes More Fatigue Than Potentiation

Article

Full-text available

Oct 2012

Lymperis Perry Koziris

Conditioning hops increase triceps surae muscle force and Achilles tendon strain energy in the stretch-shortening cycle

Article

Mar 2017

Post-activation potentiation can improve athletic performance, but the underlying mechanisms are poorly understood. This study investigated the effect of conditioning hops on triceps surae muscle force and tendon strain and its contribution to potentiated stretch-shortening cycle (SSC) performance. Thirty-two subjects participated in two experiments. In both experiments, subjects performed three drop jumps (DJs) after prior conditioning with 10 maximal hops, three unconditioned DJs served as control. Ground reaction forces, kinematics, and triceps surae electromyographic activity were recorded. Ultrasound imaging was used to determine fascicle lengths of the gastrocnemius and soleus muscles (experiment 1) and the length of the Achilles tendon (experiment 2) during the DJs. DJ height after the conditioning hops was significantly higher compared to control DJs (experiment 1: +12% and experiment 2: +19%). A significantly shorter gastrocnemius fascicle length during the DJs performed after the conditioning hops coincided with an increased force acting on the triceps surae muscle. Moreover, the triceps surae muscle-tendon unit (MTU) showed increased energy absorption during the eccentric phase of the DJs, and increased energy release during the concentric phase. The second experiment revealed a higher Achilles tendon strain in DJs performed after the conditioning hops compared to control DJs. No significant differences in muscle activities were observed. The shorter fascicle length in gastrocnemius and the larger Achilles tendon strain facilitated MTU energy transfer from the eccentric to the concentric phase during the DJ. Thereby, conditioning hops improved SSC efficacy and DJ performance. This article is protected by copyright. All rights reserved.

Potentiation of sprint cycling performance: the effects of a high-inertia ergometer warm-up

Article

Aug 2016

Participant and protocol factors affect post-activation potentiation response. Performance enhancement is more consistent in highly-trained participants following multiple sets of a biomechanically similar conditioning activity. Providing optimal conditions, 6 international-level sprint cyclists executed multiple sets of short maximal conditioning contractions on a high-inertia ergometer before metered sprint performance. Three trial conditions were completed on separate days after a standardised warm-up: dynamic (DYN: 4 × 4 crank-cycles), isometric (ISO: 4 × 5-sec maximal voluntary contraction (MVC)), and control (CON: rest). Performance was measured from standing start to maximum velocity on an inertial-load ergometer at baseline (Pre), 4 (Post4), 8 (Post8) and 16 (Post16) min post-conditioning. Performance and biomechanical measures were assessed across 4 sprint segments, with magnitude-based inferences used to assess the likelihood that any affect was beneficial. Performance time only improved in DYN Post4, a 3.9% reduction during the first crank cycle (92% likely). On the ascending limb of the power-cadence relationship, peak torque and average power increased by 6.2% (94% likely) and 4.0% (87% likely), respectively. In ISOPost16, optimal cadence increased (82% likely) and average power improved over the descending limb (76% likely). DYN and ISO potentiated extremities of the torque-cadence relationship at distinct recovery times post-conditioning. This study suggests merit in including a high-inertia warm-up for sprint cycling.

Postactivation Potentiation: Sometimes More Fatigue Than Potentiation

Article

Full-text available

Dec 2012

Lymperis Perry Koziris

CERTAIN PLYOMETRIC AND ISOMETRIC PROTOCOLS FAILED TO PRODUCE A POSTACTIVATION POTENTIATION IN VERTICAL JUMP AND BENCH PRESS THROW POWER OUTPUT. THE ISOMETRIC PROTOCOL IN PARTICULAR, NEGATIVELY AFFECTED THE STRONGEST MALE FENCERS. NONETHELESS, THE RESULTS CAN BE USEFUL IN GUIDING THE PRACTITIONER TOWARD EXPERIMENTATION WITH POSTACTIVATION POTENTIATION PROTOCOLS FOR OTHER ATHLETES.

The effects of a postactivation potentiation warm-up on subsequent sprint performance

Article

Full-text available

Mar 2014

Purpose Many strength and conditioning professionals propose that postactivation potentiation (PAP) warm-ups enhance power performance although there are few studies conducted in this regard on sprinting. Therefore, the purpose of this study was to determine the effects of a PAP warm-up on sprint performance. Methods Twenty-four men and women completed a 40-yard (yd) sprint pretest on four nonconsecutive days followed by a PAP warm-up that included a sled resistance sprint at either 0%, 10%, 20%, or 30% of their body mass and concluded with a 40-yd dash posttest. Each resistance sprint was recorded for kinematic analysis. Results A 2 × 2 × 4 factorial mixed ANOVA revealed a statistically significant difference between sexes in 40-yd dash times ( p < 0.001). A significant main effect was found in pre- and post-40-yd dash measures regardless of sex ( p < 0.001). The results indicated no significant differences in the post-40-yd dash times between sled loads and the load by time interaction. The participants’ 40-yd dash times improved 1.2% on average after the 10% load. Improvements in dash time for the 0%, 20%, and 30% loads were greater than 2%. Sprint kinematics analysis demonstrated statistically significant differences between lighter and heavier loads. Conclusions Regardless of the significant disruptions in sprint mechanics, there appears to be a potential for heavier sled resistances to affect acute improvements in 40-yd sprint performance. However, it is unclear whether heavier sleds loads may provide greater benefit than warming up with 0% resistance.

A systematic review of the effects of upper body warm-up on performance and injury

Article

Full-text available

Feb 2015

This systematic review was conducted to identify the impact of upper body warm-up on performance and injury prevention outcomes. Web of Science, MEDLINE, SPORTDiscus, PsycINFO and Cochrane databases were searched using terms related to upper extremity warm-up. Inclusion criteria were English language randomised controlled trials from peer-reviewed journals in which investigation of upper body warm-up on performance and injury prevention outcomes was a primary aim. Included studies were assessed for methodological quality using the PEDro scale. A wide variety of warm-up modes and outcomes precluded meta-analysis except for one group of studies. The majority of warm-ups were assessed as having 'positive', 'neutral', 'negative' or 'specific' effects on outcomes. Thirty-one studies met the inclusion criteria with 21 rated as having 'good' methodological quality. The studies investigated a total of 25 warm-up modes and 43 outcome factors that could be grouped into eight mode and performance outcome categories. No studies of upper body warm-up effects on injury prevention were discovered. Strong research-based evidence was found for the following: high-load dynamic warm-ups enhance power and strength performance; warm-up swings with a standard weight baseball bat are most effective for enhancing bat speed; short-duration static stretching warm-up has no effect on power outcomes; and passive heating/cooling is a largely ineffective warm-up mode. A clear knowledge gap in upper body warm-up literature is the lack of investigation of injury prevention outcomes. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Update Your Warm-Up Approach to Training and Competition

Article

Full-text available

Jan 2012

Charilaos Tsolakis

Effects of different isokinetic knee extension warm-up protocols on muscle performance

Article

Full-text available

Jan 2013

Aim: The optimal warm-up protocol for isokinetic strength performance assessment remains unclear. Therefore, the purpose of this study was to analyze the effects of different warm-up routines on strength production in young adults. Methods: Fifteen healthy young men (24.8±3.5 years) were exposed to five different isokinetic warm-up protocols. Isokinetic strength was assessed after each protocol at 60°.s-1. The warm-up protocols were: (1) submaximal, 10 submaximal consecutive repetitions (50% of maximum effort) at 60°.s-1; (2) intermittent, one set of 10 maximal intermittent contractions (30 s between contractions) at 60°.s-1; (3) 180, 10 maximal consecutive repetitions at 180°.s-1; (4) 300, 10 maximal consecutive repetitions at 300°.s-1 and (5) control session (no warm-up). Results: Peak torque was greater (P<0.05) after the intermittent (295.3±53.2 N.m) when compared to 300 (267.5±47.3 N.m) and 180 (275.2±48.6 N.m) warm-up protocols. Also, peak torque was higher (P<0.05) in the control (285.4±48.7 N.m) protocol when compared to 300. Load range was greater (P<0.05) in both no warm-up (121.5±3.5 ms) and intermittent (121.6±2.4 ms) protocols when compared to 300 (118.4±6.7 ms) and submaximum (117.7±5.5 ms) warm-up protocols. Power did not differ among protocols (P=0.31). Conclusion: Warm-up is not necessary before isokinetic tests, however, for those subjects that believe in physiological benefits of warm-up, the intermittent protocol could be an interesting strategy. In addition, subjects should avoid warm-up using velocities higher than the testing velocity.

Post-Activation Potentiation (PAP) in Sports Performance

Article

Full-text available

Dec 2024

The aim of this study is to compile and analyze the existing knowledge on post activation potentiation (PAP). By examining the mechanisms of PAP, its effects on performance, and its role in sports applications in detail, this study seeks to contribute to the sports sciences literature. The relationship between PAP and fatigue, its integration into training protocols, and its effects on individual differences will be addressed. The study aims to lay the groundwork for the development of strategies to enhance athletes' performance. Research indicates that PAP affects performance metrics such as jumping, sprinting, strength, and endurance. The literature highlights that many of these effects vary depending on time. Studies show that PAP effects are more pronounced in stronger individuals. Particularly, plyometric exercises and less deep squat movements have been observed to enhance the PAP effect. This creates favorable conditions for muscle fibers to generate potential more effectively. However, the functional significance of PAP in terms of performance and its long-term effects are not yet fully understood, necessitating further research in this area.

The Acute Effect Of Warm-Up (General And Post-Activation Potentiation) On Vertical Jump And Jump-Landing Technique Of Handball Players With Trunk Dysfunction

Article

Full-text available

Dec 2023

How to activate the glutes best? Peak muscle activity of acceleration-specific pre-activation and traditional strength training exercises

Article

Full-text available

Jan 2024
EUR J APPL PHYSIOL

Purpose Isometric training and pre-activation are proven to enhance acceleration performance. However, traditional strength training exercises do not mirror the acceleration-specific activation patterns of the gluteal muscles, characterized by ipsilateral hip extension during contralateral hip flexion. Therefore, the aim of the study was to determine gluteal muscle activity of acceleration-specific exercises compared to traditional strength training exercises. Methods In a cross-sectional study design, the peak electromyographic activity of two acceleration-specific exercises was investigated and compared to two traditional strength training exercises each for the gluteus maximus and medius. Twenty-four participants from various athletic backgrounds (13 males, 11 females, 26 years, 178 cm, 77 kg) performed four gluteus maximus [half-kneeling glute squeeze (HKGS), resisted knee split (RKS), hip thrust (HT), split squat (SS)] and four gluteus medius [resisted prone hip abduction (RPHA), isometric clam (IC), side-plank with leg abduction (SP), resisted side-stepping (RSS)] exercises in a randomized order. Results The RKS (p = 0.011, d = 0.96) and the HKGS (p = 0.064, d = 0.68) elicited higher peak gluteus maximus activity than the SS with large and moderate effects, respectively. No significant differences (p > 0.05) were found between the HT, RKS and HKGS. The RPHA elicited significantly higher gluteus medius activity with a large effect compared to RSS (p < 0.001, d = 1.41) and a moderate effect relative to the SP (p = 0.002, d = 0.78). Conclusion The acceleration-specific exercises effectively activate the gluteal muscles for pre-activation and strength training purposes and might help improve horizontal acceleration due to their direct coordinative transfer.

Post-Eccentric Flywheel Underwater Undulatory Swimming Potentiation in Competitive Swimmers

Article

Full-text available

Apr 2021
J HUM KINET

Underwater undulatory swimming (UUS) influences overall swimming performance, therefore swimmers should try to maximize it. This research aimed to: 1) assess the effects of an activation protocol based on post-activation performance enhancements upon UUS; and 2) evaluate the differences between males and females. Seventeen competitive swimmers (male = 10; female = 7) participated in a cross-sectional study designed to test performance in UUS at 10 m after a traditional swimming warm-up (TRA) and after adding to the TRA 4 maximal half-squat repetitions on an inertial flywheel device (PAPE). A speedometer and an electronic timing system were used to obtain kinematic variables such as time, frequency and velocity at 10-m, which were processed with MATLAB ®. A paired sample t test was applied to determine the differences of the kinematic variables between the TRA and PAPE. An independent sample t test was used to determine the effects of the PAPE in males and females. Participants reduced the time to cover 10 m after PAPE compared to the TRA (males: 5.77 ± 0.44 to 5.64 ± 0.46; females 6.34 ± 0.80 to 6.09 ± 0.66; p < 0.05). In addition, trends towards improvements in UUS velocity were obtained for males and females. However, push-off velocity and frequency showed a different tendency between genders (p < 0.05). In conclusion, the warm-up including repetitions on the flywheel device improved UUS performance. Some differences were obtained between genders after PAPE. Further research should confirm if the benefits obtained after the eccentric overload would depend either on gender or on other components such as fiber type composition.

A Comparison of Different Prerace Warm-Up Strategies on 1-km Cycling Time-Trial Performance

Article

Jan 2019

Purpose: Ischemic preconditioning (IPC) and postactivation potentiation (PAP) are warm-up strategies proposed to improve high-intensity sporting performance. However, only few studies have investigated the benefits of these strategies compared with an appropriate control (CON) or an athlete-selected (SELF) warm-up protocol. Therefore, this study examined the effects of 4 different warm-up routines on 1-km time-trial (TT) performance with competitive cyclists. Methods: In a randomized crossover study, 12 well-trained cyclists (age 32 [10] y, mass 77.7 [4.6] kg, peak power output 1141 [61] W) performed 4 different warm-up strategies-(CON) 17 minutes CON only, (SELF) a self-determined warm-up, (IPC) IPC + CON, or (PAP) CON + PAP-prior to completing a maximal-effort 1-km TT. Performance time and power, quadriceps electromyograms, muscle oxygen saturation (SmO2), and blood lactate were measured to determine differences between trials. Results: There were no significant differences (P > .05) in 1-km performance time between CON (76.9 [5.2] s), SELF (77.3 [6.0] s), IPC (77.0 [5.5] s), or PAP (77.3 [5.9] s) protocols. Furthermore, there were no significant differences in mean or peak power output between trials. Finally, electromyogram activity, SmO2, and recovery blood lactate concentration were not different between conditions. Conclusions: Adding IPC or PAP protocols to a short CON warm-up appears to provide no additional benefit to 1-km TT performance with well-trained cyclists and is therefore not recommended. Furthermore, additional IPC and PAP protocols had no effect on electromyograms and SmO2 values during the TT or peak lactate concentration during recovery.

Protocolización de la post-activación potenciación estimulada (PAPE) en natación y su relación con la fuerza relativa

Article

Full-text available

Feb 2020

Objective: This study tried a post-activation performance enhancements protocol in 16 competitive swimmers. Method: First, maximal conditioning exercises for upper and lower limbs were applied and tested after 5, 8, 12 and 20 minutes of rest through maximal voluntary contractions’ test (3 reps of vertical jump and 3 reps of flying push-up). On a subsequent session, specific conditioning exercises were applied again in both limbs and its effects were assessed on a 50-m swimming race after providing the same rest time in what the best performance was detected (8 min). Finally, the relative strength index was obtained in all the participants to study the relationship with the swimming performance variables. Results: All the variables related to swimming start performance improved. The velocity during flight was higher due to an increase of the forces produced against the block. The swimming time to 50-m was similar to obtained after the standard condition although swimming velocities were higher at the beginning of the race. Conclusions: The subjects with higher relative strength index obtained better results and reacted better to post-activation performance enhancements, possibly because its effects are larger in type II fibers and they are more frequent in trained subjects.

Effects of a functional lower extremity fatigue protocol and a 5-minute recovery period on the performance of a single leg hop test for distance in healthy participants

Article

Sep 2018
J SPORT MED PHYS FIT

Background: Hop tests evaluate lower extremity sport-specific performance after various interventions and as predictors of injury. The purpose of this study was to investigate the effect of a functional low-cost fatigue protocol and a 5-min post fatigue recovery on the single-leg hop test for distance (SLHD) in healthy young adult college students, including a between-gender comparison. Methods: 60 young healthy adults (37 male-23 female), without any musculosketal complaints or previous injury or surgery in any of their lower limbs, participated in the experiment. Three practice trials were initially performed, followed by three pre-fatigue formal trials of the SLHD. After the fatigue protocol, three more trials were conducted prior to a 5-min recovery period, followed by another 3 trials. The reliability of the non-fatigued SLHD was also tested in a random sample of the cohort. Results: Test-retest reliability was high (ICC2,3=0.91, SEM=7.9 cms). Mean decrease in performance between pre-fatigue and post-fatigue values was statistically significant for the whole group (-6.4%) and the male (-7.1%), however not the female participants. Mean increase between post-fatigue and 5-min recovery trials, however, was significant for all (14.7%), as well as for the male (17.5%) and female (10.2%) participants. The 5-min recovery trials were significantly increased even compared to the pre-fatigue trials for the whole group (6.6%) and the male participants (8.5%). Conclusions: The particular fatigue protocol moderately affected SLHD values, mostly for the male participants of the population recruited. Mean increase between pre-fatigue and 5-min post-fatigue recovery data can be accounted mainly by post-activation potentiation.

A study of kinesthetic after-effects on shot-put performance

Article

Dec 2014

The purpose of this study was to examine kinesthetic after-effects on shot-put performance. In experiment 1, involving 22 male university students, it was examined whether any kinesthetic after-effects would be evident in terms of throwing distance when shots of different weights were thrown. The results demonstrated a kinesthetic after-effect: the participants felt that it was easier to throw a standard-weight shot (4.0 kg) after throwing a heavier shot (5.45 kg), and they performed better in terms of throwing distance. However, no difference in throwing distance was evident when the standard-weight shot was thrown after throwing a lighter one (2.72 kg), although a kinesthetic after-effect was observed. In experiment 2, involving 16 male university students, it was examined whether any kinesthetic after-effect or improvement of throwing distance would result from throwing different weights of heavier shots (5.0 kg and 6.0 kg) before throwing the standard-weight shot (4.0 kg) 5 times. Kinesthetic after-effects and improvements in throwing distance were observed. However, there was no difference in the distances of the five throws corresponding to the weights of the shots. In experiment 3, involving 27 male university students, it was examined whether any kinesthetic after-effect or improvement in throwing distance would be evident when there was a difference in time interval after throwing a heavier shot (6.0 kg). Although kinesthetic after-effects and improvements in throwing distance were observed, there was no difference according to time interval. The above results suggest that shot-put performance would improve due to after-effects caused by throwing heavier shots. This improvement in performance might be explained by ‘post-activation potentiation’ and ‘perceptional illusion’ resulting from throwing heavier shots.

Complex of contrast training? Deel 2: Praktische richtlijnen

Article

Full-text available

Dec 2014

In het eerste deel van dit tweeluik (zie Sportgericht 3/2014) is het verschil tussen de complexmethode, complextraining en contrasttraining toegelicht. Bij deze trainingsvormen staat meestal staat het bewerkstelligen van ‘post activation potentiation’ (PAP) centraal bij deze trainingsvormen. Dit tweede artikel gaat in op de extrinsieke en intrinsieke factoren die van invloed zijn op de mate van PAP, de opbouw en het herstel van vermoeidheid en hierdoor ook op de uiteindelijke prestatie. Waar mogelijk zal hierbij een onderscheid worden gemaakt tussen complex- en contrasttraining.

Complex training of contrast training? Twee varianten van de complex methode om post activatie potentiatie uit te lokken.

Article

Full-text available

Jun 2014

In dit eerste van twee artikelen wordt het verschil tussen de begrippen complexmethode, contrasttraining en complextraining uitgelegd in relatie tot het verschijnsel ‘post activation potentiation’ (PAP). In deel twee zullen intrinsieke en extrinsieke factoren van PAP worden besproken in combinatie met bevindingen uit een lopend onderzoek bij Nederlandse topsporters.

Volume, intensity, and timing of muscle power potentiation are variable

Article

Full-text available

Oct 2011

Whereas muscle potentiation is consistently demonstrated with evoked contractile properties, the potentiation of functional and physiological measures is inconsistent. The objective was to compare a variety of conditioning stimuli volumes and intensities over a 15-min recovery period. Twelve volleyball players were subjected to conditioning stimuli that included 10 repetitions of half squats with 70% of 1-repetition maximum (RM) (10 × 70), 5 × 70, 5 × 85, 3 × 85, 3 × 90, 1 × 90, and control. Jump height, power, velocity, and force were measured at baseline, 1, 3, 5, 10, and 15 min. Data were analysed with a 2-way repeated measure ANOVA and magnitude-based inferences. The ANOVA indicated significant decreases in jump height, power, and velocity during recovery. This should not be interpreted that no potentiation occurred. Each dependent variable reached a peak at a slightly different time: peak jump height (2.8 ± 2.3 min), mean power (3.6 ± 3.01 min), peak power (2.5 ± 1.8 min), and peak velocity (2.5 ± 1.8 min). Magnitude-based inference revealed that both the 5 × 70 and 3 × 85 protocol elicited changes that exceeded 75% likelihood of exceeding the smallest worthwhile change (SWC) for peak power and velocity. The 10 × 70 and the 5 × 70 had a substantial likelihood of potentiating peak velocity and mean power above the SWC, respectively. Magnitude-based inferences revealed that while no protocol had a substantial likelihood of potentiating the peak vertical jump, the 5 × 70 had the most consistent substantial likelihood of increasing the peak of most dependent variables. We were unable to consistently predict if these peaks occurred at 1, 3, or 5 min poststimulation, though declines after 5 min seems probable.

Post-Activation Potentiation

Article

Full-text available

Jul 2005

The response of muscle to volitional or electrically induced stimuli is affected by its contractile history. Fatigue is the most obvious effect of contractile history reflected by the inability of a muscle to generate an expected level of force. However, fatigue can coexist with post-activation potentiation (PAP), which serves to improve muscular performance, especially in endurance exercise and activities involving speed and power. The measured response of muscular performance following some form of contractile activity is the net balance between processes that cause fatigue and the simultaneous processes that result in potentiation. Optimal performance occurs when fatigue has subsided but the potentiated effect still exists. PAP has been demonstrated using electrically induced twitch contractions and attributed to phosphorylation of myosin regulatory light chains, which makes actin and myosin more sensitive to Ca2+. The potentiated state has also been attributed to an increase in α-motoneuron excitability as reflected by changes in the H-reflex. However, the significance of PAP to functional performance has not been well established. A number of recent studies have applied the principles of PAP to short-term motor performance as well as using it as a rationale for producing long-term neuromuscular changes through complex training. Complex training is a training strategy that involves the execution of a heavy resistance exercise (HRE) prior to performing an explosive movement with similar biomechanical characteristics, referred to as a complex pair. The complex pair is then repeated for a number of sets and postulated that over time will produce long-term changes in the ability of a muscle to generate power. The results of these studies are equivocal at this time and, in fact, no training studies have actually been undertaken. The discrepancies among the results of the various studies is due in part to differences in methodology and design, with particular reference to the mode and intensity of the HRE, the length of the rest interval within and between the complex pairs, the type of explosive activity, the training history of the participants, and the nature of the dependent variables. In addition, few of the applied studies have actually included measures of twitch response or H-reflex to determine if the muscles of interest are potentiated. There is clearly more research required in order to clarify the functional significance of PAP and, in particular, the efficacy of complex training in producing long-term neuromuscular adaptations.

MVC-induced short-term potentiation of explosiv force

Article

Full-text available

Jan 1996

PQ] © by IAAF 11:4:67-81,1996 % ^ /n numerous sports and sport events performance is, to a great extent, determined by the level of speed-strength. An optimal preparation (worm-up) is necessary to achieve the highest possible realization of speed-strength in training and competition. Some top international athletes ore said to have produced the highest speed and speed-strength performances immediately after having performed a few Maximal Voluntary Contractions (MVCs). However, os yet no target-oriented and systematic studies of MVCs. as an element of warm-up programmes, have been conducted. Therefore the focus of the following study is on the following questions: (1) To what extent can the short-term potentia-tion of speed-strength induced by MVCs be considered us a general effect? (2) Can effects of post-tetanic potentiation be triggered in human beings by MVCs? (3) To what extent Is there a connection between possible short-term increases in speed-strength and neuronal effects of post-tetanic potentiation? The results of two complex training experiments show that MVCs carried out during the warm-up can really lead to a considerable increase In speed-strength performances of the lower extremities in alt athletics sprint and jumping events and of the upper extremities in the shot put and the throws, m ^ Dr Arne Gütlich was. from 1992 to 1996.

Relationship between strength qualities and sprinting performance

Article

Full-text available

Apr 1995

The purpose of this study was to investigate the relationship between strength measures and sprinting performance, and to determine if these relationships varied for different phases of sprint running. Twenty (11 males and 9 females) elite junior track and field athletes served as subjects. Athletes performed maximum sprints to 50 m from a block start and time to 2.5, 5, 10, 20, 30, 40 and 50 m were recorded by electronic timing gates. The resultant forces applied to the blocks were obtained from two force platforms. Twenty-seven measures of strength and speed-strength (absolute and relative to bodyweight) were collected from the height jumped and the force-time curve recorded from the takeoff phase of vertical jumping movements utilizing pure concentric, stretch shortening cycle (SSC) and isometric muscular contractions. Pearson correlation analysis revealed that the single best predictor of starting performance (2.5 m time) was the peak force (relative to bodyweight) generated during a jump from a 120 degree knee angle (concentric contraction) (r = 0.86, p = 0.0001). The single best correlate of maximum sprinting speed was the force applied at 100 ms (relative to bodyweight) from the start of a loaded jumping action (concentric contraction) (r = 0.80, p = 0.0001). SSC measures and maximum absolute strength were more related to maximum sprinting speed than starting ability. It was concluded that strength qualities were related to sprinting performance and these relationships differed for starting and maximum speed sprinting.

Threshold for force potentiation associated with skeletal myosin phosphorylation

Article

Full-text available

Dec 1993
Am J Physiol

Phosphate incorporation by the phosphorylatable light chains (P-LC) of myosin is associated with isometric twitch force potentiation in intact fast-twitch muscle. The purpose of this study was to examine the association between myosin P-LC phosphorylation and force potentiation at higher stimulation frequencies (1-150 Hz) using mouse extensor digitorum longus (EDL) muscles at 25 degrees C. Peak isometric force and the peak rate of isometric force development (+dF/dtmax) were measured at selected test frequencies before and after the application of a 5-Hz 20-s conditioning stimulation known to increase P-LC phosphate content. Associated with a ninefold elevation in myosin P-LC phosphate content (to 0.72 mol phosphate/mol P-LC), +dF/dtmax was increased at all test frequencies (mean 27%, range 20-37%). After the conditioning stimulus, peak isometric force was increased by approximately 15% for frequencies 1-15 Hz. However, at 20-150 Hz, the increase in +dF/dtmax was not associated with force potentiation, since peak force was diminished by 5-40%. These data reveal that the stimulation frequency limit for the potentiation of peak force production associated with myosin P-LC phosphorylation is < 20 Hz in mouse EDL at 25 degrees C. Furthermore, the data suggest that increases in the rate constant describing the rate of cross-bridge transition from a non-force-generating to a force-generating state mediated by myosin P-LC phosphorylation may be responsible for the general increase in +dF/dtmax and for the force potentiation at 1-15 Hz.

Potentiation of in vitro concentric work in mouse fast muscle

Article

Full-text available

Jan 1998

Phosphorylation of myosin regulatory light chain (R-LC) is associated with potentiated work and power during twitch afterloaded contractions in mouse extensor digitorum longus muscle [R. W. Grange, C. R. Cory, R. Vandenboom, and M. E. Houston. Am. J. Physiol. 269 (Cell Physiol. 38): C713-C724, 1995]. We now describe the association between R-LC phosphorylation and potentiated concentric work when the extensor digitorum longus muscle is rhythmically shortened and lengthened to simulate contractions in vivo. Work output (at 25 degrees C) was characterized at sine frequencies of 3, 5, 7, 10, and 15 Hz at excursions of 0.6, 1.2, and 1.6 mm (approximately 5, 9, and 13% optimal muscle length) at a low level of R-LC phosphorylation. Muscles stimulated during the sine function with a single twitch at specific times before or after the longest muscle length yielded maximal concentric work near the longest muscle length at a sine frequency of 7 Hz (e.g., excursion approximately 9% optimal muscle length = 1.6 J/kg). Power increased linearly between sine frequencies of 3 and 15 Hz at all excursions (maximum approximately 29 W). After a 5-Hz 20-s conditioning stimulus and coincident with a 3.7-fold increase in R-LC phosphate content (e.g., from 0.19 to 0.70 mol phosphate/mol R-LC), work at the three excursions and a sine frequency of 7 Hz was potentiated a mean of 25, 44, and 50% (P < 0.05), respectively. The potentiated work during rhythmic contractions is consistent with enhanced interaction between actin and myosin in the force-generating states. On the basis of observations in skinned skeletal muscle fibers (H. L. Sweeney and J. T. Stull. Proc. Natl. Acad. Sci. USA 87:414-418, 1990), this enhancement could result from increased phosphate incorporation by the myosin R-LC. Under the assumption that the predominant effect of the conditioning stimulus was to increase R-LC phosphate content, our data suggest that a similar mechanism may be evident in intact muscle.

Postexercise potentiation of the H-reflex in humans

Article

Full-text available

Jul 1998

Post-muscle activation effects on segmental reflexes reveal divergent results dependent upon the manner in which the muscle is activated. Electrically activating triceps surae invokes a potentiation of the Achilles' tendon reflex and the soleus (S) H-reflex termed posttetanic potentiation. In contrast, brief volitional activation produces a subsequent potentiation of tendon reflexes, whereas H-reflexes become depressed. The present investigation explored the effect of an intense bout of volitional resistance exercise on the S and lateral gastrocnemius (LG) H-reflexes to determine if a potentiation of the H-reflex could be induced with physiological stimuli. LG and S H-reflexes were obtained from 10 college age men and women before and after a vigorous bout (eight sets of 10 repetitions) of concentric-eccentric triceps surae exercise. Every subject displayed an initial depression of the LG (P < 0.01) and S H-reflex (P < 0.05) immediately postexercise, consistent with postactivation depression. As a group, there was a significant (P > 0.01) potentiation of the LG H/M ratio following the depression. Five of 10 subjects demonstrated this potentiation, which often lasted 10 min postexercise. The other five subjects displayed a longer and more profound early depression followed by a return to control levels. The data suggest that at least two overlapping processes are occurring, a brief depression followed by or superimposed over a longer lasting potentiation. Possible neural mechanisms and implications to strength training are discussed.

Coexistence of potentiation and fatigue in skeletal muscle

Article

Full-text available

Jun 2000
BRAZ J MED BIOL RES

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 Effects of High-Intensity Exercise on a 10-Second Sprint Cycle Test

Article

Full-text available

Sep 2001

Nine men (25.11 +/- 1.16 years) performed 3 different test sessions. In the control session, subjects performed a 10-second sprint cycle test and 1 repetition maximum (1RM) in the back squat. The 5-minute test session consisted of 10 x 1 repetition in the parallel back squat exercise at 90% of their 1RM, 5 minutes of rest, and then a 10-second sprint cycle test. The 20-minute test session consisted of the same test protocol as the 5-minute test session except that the subjects rested for 20-minutes prior to the sprint cycle test. Significant differences were found in average power and average power relative to body weight (F = 5.684, p = 0.014, and F = 1.258, p = 0.006, respectively) for the 5-minute test session. The authors conclude that this particular squat protocol could have a potential carry-over effect into improvements in 100-m sprint times when performing the squats 5-minutes prior to performance.

What Is Fatigue?

Article

Full-text available

Mar 2002

Fatigue and potentiation are two forms of force modulation. A general definition of fatigue is "a circumstance where less than the anticipated contractile response is obtained." Fatigue is associated with depressed Ca2+ release and possibly decreased Ca2+ sensitivity. Potentiation results from increased Ca2+ sensitivity due to regulatory light chain phosphorylation. Muscle fatigue and potentiation can coexist, making it difficult to quantify these processes. With repetitive 10Hz stimulation, the developed tension first increases, then decreases. Is fatigue present when developed tension first begins to decrease or when it falls below the developed tension of the first response? Intermittent incompletely fused tetanic contractions for which peak developed tension first decreases, then increases, is another unusual example of fatigue. A third example is when twitch contractions following a tetanic contraction decrease to a level below the pretetanic twitch amplitude, indicating that fatigue may have been coexistent with posttetanic potentiation. These observations illustrate the complexity of detecting fatigue, based on the simple, but commonly accepted definition presented above. Care must be taken in interpreting "before vs. after" contractile responses. Even when the contraction amplitude is greater than the initial response, there is no guarantee that mechanisms associated with fatigue are not present.

Effect of a Submaximal Half-Squats Warm-up Program on Vertical Jumping Ability

Article

Full-text available

Jun 2003

The purpose of the current research was to study the effect of a warm-up program including submaximal half-squats on vertical jumping ability. Twenty physically active men participated in the study. Each subject performed 5 sets of half-squats with 2 repetitions at each of the following intensities: 20, 40, 60, 80, and 90% of the 1 repetition maximum (1RM) load. Prior to the first set and immediately after the end of the last set, the subjects performed 2 countermovement jumps on a Kistler force platform; the primary goal was to jump as high as possible. The results showed that mean vertical jumping ability improved by 2.39% after the warm-up period. Subjects were then divided into 2 groups according to their 1RM values for the half-squat. Subjects with greater maximal strength ability improved their vertical jumping ability (4.01%) more than did subjects with lower maximal strength (0.42%). A warm-up protocol including half-squats with submaximal loads and explosive execution can be used for short-term improvements of vertical jumping performance, and this effect is greater in athletes with a relatively high strength ability.

Postactivation Potentiation Response in Athletic and Recreationally Trained Individuals

Article

Full-text available

Nov 2003

To determine if training status directly impacted the response to postactivation potentiation, athletes in sports requiring explosive strength (ATH; n = 7) were compared to recreationally trained (RT; n = 17) individuals. Over the course of 4 sessions, subjects performed rebound and concentric-only jump squats with 30%, 50%, and 70% 1 RM loads. Jump squats were performed 5 minutes and 18.5 minutes following control or heavy load warm-ups. Heavy load warm-up consisted of 5 sets of 1 repetition at 90% 1 RM back squat. Jump squat performance was assessed with a force platform and position transducer. Heavy load warm-up did not have an effect on the subjects as a single sample. However, when percent potentiation was compared between ATH and RT groups, force and power parameters were significantly greater for ATH (p < 0.05). Postactivation potentiation may be a viable method of acutely enhancing explosive strength performance in athletic but not recreationally trained individuals. Reference Data: Chiu, L.Z.F., A.C. Fry, L.W. Weiss, B.K. Schilling, L.E. Brown, and S.L. Smith. Postactivation potentiation response in athletic and recreationally trained individuals.

Acute Effects of Heavy Preloading on Vertical and Horizontal Jump Performance

Article

Full-text available

Jun 2004

The purpose of this study was to investigate the acute effects of a heavy dynamic preload, consisting of 1 set of 5 repetition maximum (5RM) back squats, on countermovement vertical jump (VJ) and horizontal jump (HJ) performance. The study also investigated the ability of subjects to learn to apply the effects of the preload over subsequent training sessions. Nineteen (N = 19) resistance-trained men (age = 25.0 +/- 4.8 years; weight = 79.3 +/- 6.6 kg) participated in the study. Each subject took part in 4 practice and 4 testing sessions. The 4 practice sessions were included to allow for any learning effects of VJ and HJ to stabilize and to establish a true 5RM back squat. The 4 testing sessions were included to see if subjects were able to capitalize on the repeat exposure to the protocol. One practice session consisted of a 10-minute warm-up (5 minutes of cycling and 5 minutes of stretching), 2 sets of VJ and HJ (each set of VJ and HJ consisted of 4 jump repetitions) with a 5-minute rest between sets, progressive 5RM back squat evaluation, and 2 final sets of VJ and HJ. Both VJ and HJ increased approximately 2% over the 4 practice sessions, and 5RM back squat strength improved from 164.2 +/- 25.1 kg to 196.9 +/- 23.0 kg (p < or = 0.05). The 4 testing sessions each consisted of the standardized warm-up, 1 set of 4 VJs and HJs, a 5-minute rest, 5RM back squat, a 5-minute rest, and the final set of VJs and HJs. Pre- and post-5RM VJ and HJ order was randomly assigned. The results indicated no significant differences occurred between the mean or maximal values for either VJ or HJ as a consequence of the dynamic preload exercise. In addition, the results reflected an inability of subjects to benefit from the repeated exposure to the heavy dynamic preload exercise protocol.

Short-Term Effects of Selected Exercise and Load in Contrast Training on Vertical Jump Performance

Article

Full-text available

Mar 2005

The present study examined the short-term effects of loaded half squats (HSs) and loaded jump squats (JSs) with low and moderate loads on the squat jump (SJ) and the countermovement jump (CMJ) performance using a contrast training approach. Ten men (mean +/- SD age, 23 +/- 1.8 years) performed the HS and JS exercises twice with loads of 30% of 1 repetition maximum (1RM) (HS30% and JS30%, respectively) and 60% of 1RM (HS60% and JS60%, respectively). On each occasion, 3 sets of 5 repetitions with 3 minutes of rest were performed as fast as possible. Vertical jump performance was measured before exercise, 1 minute after each set, and at the fifth and 10th minutes of recovery. The CMJ increased significantly after the first and second set (3.9%; p < 0.05) compared with preexercise values following the JS30% protocol and 3.3% after the second and third sets of the JS60% protocol. Following the HS60% protocol, CMJ increased after the first and the second sets (3.6%; p < 0.05) compared with preexercise values, whereas SQ increased only after the first set (4.9%; p < 0.05) in this condition. These data show that contrast loading with the use of low and moderate loads can cause a short-term increase in CMJ performance. The applied loads do not seem to present different short-term effects after loaded JSs. When the classic form of dynamic HS exercise is performed, however, at least a moderate load (60% of 1RM) needs to be applied.

Post-activation potentiation: underlying physiology and implications for motor performance

Article

Full-text available

Feb 2005

The response of muscle to volitional or electrically induced stimuli is affected by its contractile history. Fatigue is the most obvious effect of contractile history reflected by the inability of a muscle to generate an expected level of force. However, fatigue can coexist with post-activation potentiation (PAP), which serves to improve muscular performance, especially in endurance exercise and activities involving speed and power. The measured response of muscular performance following some form of contractile activity is the net balance between processes that cause fatigue and the simultaneous processes that result in potentiation. Optimal performance occurs when fatigue has subsided but the potentiated effect still exists. PAP has been demonstrated using electrically induced twitch contractions and attributed to phosphorylation of myosin regulatory light chains, which makes actin and myosin more sensitive to Ca(2+). The potentiated state has also been attributed to an increase in alpha-motoneuron excitability as reflected by changes in the H-reflex. However, the significance of PAP to functional performance has not been well established. A number of recent studies have applied the principles of PAP to short-term motor performance as well as using it as a rationale for producing long-term neuromuscular changes through complex training. Complex training is a training strategy that involves the execution of a heavy resistance exercise (HRE) prior to performing an explosive movement with similar biomechanical characteristics, referred to as a complex pair. The complex pair is then repeated for a number of sets and postulated that over time will produce long-term changes in the ability of a muscle to generate power. The results of these studies are equivocal at this time and, in fact, no training studies have actually been undertaken. The discrepancies among the results of the various studies is due in part to differences in methodology and design, with particular reference to the mode and intensity of the HRE, the length of the rest interval within and between the complex pairs, the type of explosive activity, the training history of the participants, and the nature of the dependent variables. In addition, few of the applied studies have actually included measures of twitch response or H-reflex to determine if the muscles of interest are potentiated. There is clearly more research required in order to clarify the functional significance of PAP and, in particular, the efficacy of complex training in producing long-term neuromuscular adaptations.

The Best Warm-Up for the Vertical Jump in College-Age Athletic Men

Article

Full-text available

Aug 2005

The purpose of this study was to determine the effectiveness of specific and nonspecific warm-ups on the vertical jump test performed by athletic men. Twenty-nine men (18-23 years) in athletics (speed positions in football) performed vertical jump tests on 4 separate days after completing 4 different warm-up protocols. The 4 warm-up protocols were (a) submaximal jump warm-up, (b) weighted jump warm-up, (c) stretching warm-up, and (d) no warm-up. The weighted jump warm-up protocol required 5 countermovement jumps onto a box, with the athletes holding dumbbells equaling 10% of their body weight. The submaximal jump warm-up protocol required the athletes to perform 5 countermovement jumps at 75% intensity of their past maximum vertical jump score. The stretching warm-up protocol required the athletes to perform 14 different stretches, each held for 20 seconds. The no warm-up protocol required the athletes to perform no activity prior to being tested. Three vertical jumps were measured following each warm-up; the score for analysis was the best jump. The data were analyzed with a repeated measures analysis of variance and Bonferroni post hoc tests. The Bonferroni post hoc tests showed a significant difference (p < 0.001) between the weighted jump warm-up and all other warm-ups. The effect size was 0.380 and the power was 1.00 for the statistical analyses. We concluded that utilizing a weighted resistance warm-up would produce the greatest benefit when performing the vertical jump test.

Effect of Loading on Enhancement of Power Performance Over Three Consecutive Trials

Article

Full-text available

Nov 2005

The acute effects of maximal voluntary isometric contractions (MVICs) in the squat position on subsequent measures of power output over 3 consecutive sets were investigated. Sixteen trained men experienced with back squats participated in the study. A 7-second MVIC was performed 4 minutes before the execution of 5 maximal countermovement jumps (CMJs) and was repeated for 3 consecutive sets (protocol 1). The results were compared to power output performance in a similar protocol (protocol 2) that excluded the 7-second MVICs. No significant differences occurred in any of the power output measurements between protocol 1 and protocol 2, nor did significance occur linearly across the 4 sets of CMJ, with the exception of a decrease in peak power in protocol 2 (p < or = 0.05). Using both mean and maximal values only one significant correlation between either relative strength and performance enhancement or absolute strength and performance enhancement was present at p < or = 0.01. At p < or = 0.05, significant correlations were found between absolute strength and mean peak power (PP), mean peak acceleration (PA), mean peak force (PF), max PP, max PA, max PF, and max peak velocity. These data indicate that the execution of an MVIC performed before a power exercise was inadequate to acutely enhance power output over any of 3 consecutive trials.

Effects of General, Special, and Specific Resistance Training on Throwing Velocity in Baseball

Article

Feb 2001

Throwing velocity is a necessary requirement for success in baseball. All position players, including pitchers, may increase their defensive performance if their throwing velocity is improved. A review of the literature suggests that throwing velocity can be increased by resistance training and/or biomechanical improvement of the throwing motion. This paper reviews the 3 broad categories of resistance-training methods by which throwing velocity is increased. The results of research using general, special, and specific throwing resistance-training exercises are presented. The role and applications of these different exercises for baseball players of different ages are discussed.

The Acute Effects of a Resistance Training Warmup on Sprint Performance

Article

Aug 2010

Twenty male rugby union players were tested to determine the acute effect of a resistance training warmup on subsequent 20-m sprint performance. The study consisted of a repeated measures design with two experimental conditions. During the control (C) condition, the participants performed a 20-m sprint, rested for 10min, and then repeated the 20-m sprint. During the experimental (E) condition, the second sprint was preceded by five repetitions of a back-squat with a load equal to each participant's five repetition maximum (5RM). Sprint times were recorded using New Test digital recording equipment. The results showed a mean improvement of 0.098s (p<0.0001) when the second sprint was preceded by the back squats. This amounted to a 3.3% improvement on the precondition time. During the control condition, no improvement was observed between the first and second sprint. The improved sprint times observed during the E condition probably were due to a temporary increase in the efficiency of neuromuscular activation following the performance of heavy-load back squats.

Acute Enhancement of Power Performance From Heavy Load Squats

Article

May 1998

The purpose of this research was to determine whether a loaded countermovement jump (LCMJ) could be enhanced if preceded by a set of half-squats with a 5-RM load. Ten subjects experienced with the squat exercise performed 2 sets of 5 LCMJ, 1 set of 5 squat reps with a 5-RM load, and 1 set of 5 LCMJ with 4 min rest between all sets. There was no significant difference between the first 2 sets of LCMJ, and the repeatability between these sets was high. However, the jump height for the set of LCMJ after the squat set was significantly greater (2.8%) than for the LCMJ set immediately preceding the squats. It was concluded that squats with a 5-RM load produce dramatic improvements in power performance. In addition, there was a significant correlation between performance enhancement from the squats and the 5-RM load. This suggests that stronger individuals may benefit more from resistance training exercises that utilize contrasting loads. (C) 1998 National Strength and Conditioning Association

Postactivation Potentiation Response in Athletic and Recreationally Trained Individuals

Conference Paper

Jul 2003

To determine if training status directly impacted the response to postactivation potentiation, athletes in sports requiring explosive strength (ATH; n = 7) were compared to recreationally trained (RT; n = 17) individuals. Over the course of 4 sessions, subjects performed rebound and concentric-only jump squats with 30%, 50%, and 70% 1 RM loads. Jump squats were performed 5 minutes and 18.5 minutes following control or heavy load warm-ups. Heavy load warm-up consisted of 5 sets of 1 repetition at 90% 1 RM back squat. Jump squat performance was assessed with a force platform and position transducer. Heavy load warm-up did not have an effect on the subjects as a single sample. However, when percent potentiation was compared between ATH and RT groups, force and power parameters were significantly greater for ATH (p < 0.05). Postactivation potentiation may be a viable method of acutely enhancing explosive strength performance in athletic but not recreationally trained individuals. (C) 2003 National Strength and Conditioning Association

Acute Stretching Exercises and Vertical Jump Stored Elastic Energy927

Article

May 1996

Effects of Different Warm-Up Protocols on Peak Power Output During A Single Response Jump Task 1127

Article

May 1996

Effects of Warm Up With Various Weighted Implements On Baseball Bat Swing Velocity

Article

Nov 1992

The purpose of this study was to determine which of 13 weighted batting warm-up implements would produce the greatest bat velocity in subsequent trials. Sixty male high school varsity baseball players participated in a standardized warm up with one of 13 weighted implements on separate days. Bat swing velocity was determined using a photosensing computer-timer immediately after warm up. Warm up with an implement that was weighted within approximately +/-10 percent of the standard 30 oz. bat weight produced the greatest bat velocity, P < 0.05. Mean bat velocities ranged from 24.5 to 27.1 m * s-1. It was also noted that there was a trend of decreasing velocity following warm up the more the weight of the bat deviated from the standard weight bat. Additionally, the commonly used donut ring consistently resulted in the lowest bat velocity. It was concluded that to achieve the greatest bat velocity, warm up should be performed with a bat near the standard weight. (C) 1992 National Strength and Conditioning Association

Electromyographic and Kinetic Analysis of Complex Training Variables

Article

Apr 2000

The use of complex training as a method of combining weight and plyometric exercises during the same training session is growing in popularity, despite limited scientific support for its efficacy. The purpose of this study was to examine the effect of a set of high-load bench press exercises (BP) on a subsequent set of medicine ball power drop exer-cises (MBPD) via mean ground reaction force, maximum ground reaction force, and mean electromyography (EMG int). Ten male (19 1.4 years) NCAA Division 1 basketball play-ers with experience in weight and plyometric training per-formed plyometric exercises under 2 randomly determined conditions. One condition included a BP followed immedi-ately by a MBPD. The other condition included only the MBPD. Mean ground reaction force, maximum ground re-action force, and EMG int were recorded during the MBPD for both conditions. Results indicated that no significant differ-ences exist for mean ground reaction force, maximum ground reaction force, and EMG int for the pectoralis major and triceps muscles between the MBPD and the BP plus MBPD conditions. These results indicate there is no height-ened excitability of the central nervous system. However, there also appears to be no disadvantage of performing high-load weight training and plyometric exercises in com-plex pairs. Therefore, complex training may be a useful train-ing strategy because of the organizational advantages of per-forming weight and plyometric exercises in the same train-ing session.

Effects of fatigue and recovery on electromyographic and isometric force- and relasation time characteristics of human muscle

Article

Nov 1986
Eur J Appl Physiol Occup Physiol

Effects of fatigue produced by a maintained 60% isometric loading on electromyographic and isometric force-time and relaxation-time characteristics of human skeletal muscle were studied in 21 males accustomed to strength training. Fatigue loading resulted in a slight but not significant change in the maximal integrated EMG of a maximal isometric contraction, and a large decrease (20.46.3%, p<0.001) in maximal force. Fatigue loading increased (p<0.05–0.01) neural activation of the muscles during rapidly produced submaximal isometric forces, but had a considerable adverse effect (p<0.001) on the corresponding force-time characteristics. Correlations between the relative changes after fatigue in the IEMG/force ratio at the maximal force level, and in the IEMG/force ratios of the early phases of the force-time curve were not significant, but gradually became significant (p<0.01) at higher force levels. The average IEMG of the muscles in the relaxation phase of contraction remained unaltered by fatigue, while a marked deleterious change in the relaxation-time variables (p<0.001) occurred concomitantly. During the subsequent 3 min rest period considerable (12.17.0%, p<0.001) recovery was noted in the maximal force, with smaller (insignificant or p<0.05–0.01) changes in the force-time and relaxation-time variables, while the average IEMG of force production decreased (p<0.01–0.001). The present findings suggest that fatigue leading to a worsening in force-time, in maximal force and in the relaxation-time parts of a maximal isometric contraction might take place primarily in the contractile processes.

Effects of Preload 4 Repetition Maximum on 100-m Sprint Times in Collegiate Women

Article

Apr 2010
J STRENGTH COND RES

The purpose of this study was to determine the effects of postactivation potentiation (PAP) on track-sprint performance after a preload set of 4 repetition maximum (4RM) parallel back half-squat exercises in collegiate women. All subjects (n = 12) participated in 2 testing sessions over a 3-week period. During the first testing session, subjects performed the Controlled protocol consisting of a 4-minute standardized warm-up, followed by a 4-minute active rest, a 100-m track sprint, a second 4-minute active rest, finalized with a second 100-m sprint. The second testing session, the Treatment protocol, consisted of a 4-minute standardized warm-up, followed by 4-minute active rest, sprint, a second 4-minute active rest, a warm-up of 4RM parallel back half-squat, a third 9-minute active rest, finalized with a second sprint. The results indicated that there was a significant improvement of 0.19 seconds (p < 0.05), when the second sprint was preceded by a 4RM back-squat protocol during Treatment. The standardized effect size, d, was 0.82, indicating a large effect size. Additionally, the results indicated that it would be expected that mean sprint times would increase 0.04-0.34 seconds (p < 0.05), when using a preload 4RM squat protocol. There were no significant differences between Control pre and posttests (p > 0.05). The findings suggest that performing a 4RM parallel back half-squat warm-up before a track sprint will have a positive PAP affect on decreased track-sprint times. Track coaches, looking for the "competitive edge" (PAP effect) may re-warm up their sprinters during meets.

The Effects of Postactivation Potentiation on Sprint and Jump Performance of Male Academy Soccer Players

Article

Oct 2009
J STRENGTH COND RES

The purpose of this investigation was to evaluate the postactivation potentiation (PAP) effects of both dynamic and isometric maximum voluntary contractions (MVCs) on sprint and jump performance and establish whether PAP methods could be used effectively in warm up protocols for soccer players. Twelve male soccer players performed 4 warm up protocols in a cross-over, randomized, and counterbalanced design. In addition to a control warm up, subjects performed deadlift (5 repetitions at 5 repetitions maximum), tuck jump (5 repetitions), and isometric MVC knee extensions (3 repetitions for 3 s) as PAP treatments in an otherwise identical warm up protocol. After each treatment, the subjects underwent 3 10 m and 20 m sprints 4, 5, and 6 minutes post-warm up and 3 vertical jumps (VJ) at 7, 8, and 9 minutes post-warm up. Repeated measures analysis of variance showed no significant differences in the first 10 m (p = 0.258) and 20 m (p = 0.253) sprint and VJ (p = 0.703) performance and the average 10 m (p = 0.215), 20 m (p = 0.388), and VJ (p = 0.529) performance between conditions. There were also no significant differences in performance responses between the strongest and weakest subjects, but large variations in individual responses were found between the subjects. The findings suggest that there was no significant group PAP effect on sprint and jump performance after dynamic and isometric MVCs compared with a control warm up protocol. However, the large variation in individual responses (-7.1% to +8.2%) suggests PAP should be considered on an individual basis. Factors such as method, volume, load, recovery, and interindividual variability of PAP must be considered in the practical application of PAP and the rigorous research design of future studies to evaluate the potential for performance enhancement.

Muscle hypertrophy and fast fiber type conversions in heavy resistance-trained women

Article

Feb 1990
Eur J Appl Physiol Occup Physiol

Twenty-four women completed a 20-week heavy-resistance weight training program for the lower extremity. Workouts were twice a week and consisted of warm-up exercises followed by three sets each of full squats, vertical leg presses, leg extensions, and leg curls. All exercises were performed to failure using 6-8 RM (repetition maximum). Weight training caused a significant increase in maximal isotonic strength (1 RM) for each exercise. After training, there was a decrease in body fat percentage (p less than 0.05), and an increase in lean body mass (p less than 0.05) with no overall change in thigh girth. Biopsies were obtained before and after training from the superficial portion of the vastus lateralis muscle. Sections were prepared for histological and histochemical examination. Six fiber types (I, IC, IIC, IIA, IIAB, and IIB) were distinguished following routine myofibrillar adenosine triphosphatase histochemistry. Areas were determined for fiber types I, IIA, and IIAB + IIB. The heavy-resistance training resulted in significant hypertrophy of all three groups: I (15%), IIA (45%), and IIAB + IIB (57%). These data are similar to those in men and suggest considerable hypertrophy of all major fiber types is also possible in women if exercise intensity and duration are sufficient. In addition, the training resulted in a significant decrease in the percentage of IIB with a concomitant increase in IIA fibers, suggesting that strength training may lead to fiber conversions.

Influence of exercise and training on motor unit activation

Article

Feb 1987

Digby G. Sale

Human MUs vary considerably in twitch force, contractile speed, axonal conduction velocity, fatigue resistance, recruitment thresholds, firing rates, and firing patterns. These functional properties, together with the corresponding morphological characteristics such as soma size, axon diameter, and muscle fiber size, are interrelated. The smallest (soma size, axon diameter, muscle fiber size) MUs have the smallest twitch force, the slowest contraction speed, the slowest conduction velocity, the greatest resistance to fatigue, the lowest recruitme

Effects of Postactivation Potentiation Warm-up in Male and Female Sport Performances: A Brief Review

Abstract

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