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Muscle activity patterns of five muscles from the slowest speed of 3.25 m/s (thin line; mean of 170 contacts) up to the maximal speed (thick line; mean of 34 contacts). Data are the mean rectified electromyogram (EMG) measurements from a representative subject. The dashed lines indicate the respective EMG curves at the three medium running speeds and the vertical lines indicate the beginning of the contact phase. Note the greater EMG activity prior to contact (i.e. preactivation) with higher running speeds (reproduced from Kyrolainen et al., [56] with permission). 

Muscle activity patterns of five muscles from the slowest speed of 3.25 m/s (thin line; mean of 170 contacts) up to the maximal speed (thick line; mean of 34 contacts). Data are the mean rectified electromyogram (EMG) measurements from a representative subject. The dashed lines indicate the respective EMG curves at the three medium running speeds and the vertical lines indicate the beginning of the contact phase. Note the greater EMG activity prior to contact (i.e. preactivation) with higher running speeds (reproduced from Kyrolainen et al., [56] with permission). 

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Article
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Performance in endurance sports such as running, cycling and triathlon has long been investigated from a physiological perspective. A strong relationship between running economy and distance running performance is well established in the literature. From this established base, improvements in running economy have traditionally been achieved through...

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... Triathlon has been shown not to be "the sum of its component sports" since the neuromuscular alterations to cycling interfere with those elicited by running (Bonacci et al., 2009;Millet et al., 2009). Yet little research that can assist the triathlete to train in an optimal, Sprint Distance-specific, manner has been published. ...
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While the sport of short-distance (Sprint) triathlon provides an opportunity to research the effect of the center of mass (CoM) when cycling and running, much remains to be done. The literature has failed to consistently or adequately report how changes to hand position influence subsequent running as inferred by the magnitude of CoM acceleration. The demands of cycle training in a drops and aerodynamic position followed by running remain unquantified in Sprint Distance triathlon. Thus, far data collected indicate that the cycle to run transition (T2) is important for overall race success. While many age-groupers participate in Sprint Distance triathlon, the lack of T2 based research make comparisons between cycle hand position and ensuing running difficult. The motion of the human body when cycling and running in triathlon can be described by the motion of its CoM in a local coordinate system. Unobtrusive wearable sensors have proven to be an informative resource to monitor the magnitude of CoM accelerations in running. However, the extent to which they are used in cycling is unclear. Therefore, the aim of the present study was to analyse the temporal magnitudes of CoM acceleration when cycling position and cadence is changed and to analyse these effects on running after cycling. Ten recreational triathletes completed two 20 km cycling trials at varied cadence in a drops position (parts of the handlebars that curve outward, Cycle Drops) and an aerodynamic position (arms bent, forearms parallel to the ground, Cycle Aero ) immediately followed by a 5 km run at self-selected pace. Torso kinematics by way of CoM acceleration magnitude were captured in a typical training setting using a triaxial accelerometer. CoM acceleration was quantified in m/s ² and variability was measured by the coefficient of variation (CV) and root mean square (RMS). Results from Cycle Aero indicated that acceleration of the CoM in longitudinal (CV = 1%) and mediolateral directions (CV = 3%) was significantly reduced ( p < 0.001) compared to Cycle Drops . As for rate of perceived exertion (RPE), a significant difference was observed with triathletes reporting higher values in Cycle Aero alongside a greater CoM acceleration magnitude in the anteroposterior direction. The CoM varied significantly from Run Aero with less longitudinal (CV = 0.2, p < 0.001) and mediolateral acceleration observed (CV = 7.5%, p < 0.001) compared to Run Drops . Although greater longitudinal acceleration was observed in the initial 1 km epoch of Run Aero , triathletes then seemingly adjusted their CoM trajectory to record lower magnitudes until completion of the 5 km run, completing the run quicker compared to Run Drops (22.56 min ¹ ± 0.2, 23.34 min ¹ ± 0.5, p < 0.001, CV = 1.3%). Coaches may look to use triaxial accelerometers to monitor performance in both cycling and running after cycling.
... Neuromuscular changes correlating with enhanced performance are generally gained rapidly when starting any new exercise. 26 As well as providing proprioceptive challenges to the lower limb, 27 proximal muscles, particularly those of the hip and pelvis, also provide a stabilization role during a variety of singleleg exercises. 28 The runners in the current study welcomed researchbased explanations that clarified hip muscle function, having heard gluteal muscles were important in running. ...
... It is suggested that neuromuscular impairments persist following injury despite the runner having returned to running, 26 and in the current study, 91% of participants had had a previous RRI. They reported becoming more cognizant that their recurrent injuries were possibly associated with other, more proximal and/or distal areas to their site of pain. ...
Article
Context: Injury prevention programs are effective when implemented in team sports, but many recreational runners have less access to such focused interventions or peer support and often seek other sources to learn about injury reduction strategies. Objective: This study aimed to explore runners' motivations in attending a prehabilitation (prehab) for runners workshop, establish their comprehension of prehab, and identify barriers to ongoing engagement with injury prevention. Design: Qualitative study using focus groups. Participants and setting: Twenty-two runners participating in prehab for runners workshops took part in one of 4 focus groups, each recorded, transcribed, and analyzed using Grounded Theory to create codes, subthemes, and themes. Results: Four themes emerged: (1) Participation was influenced by experience of previous injury and worry of cessation of running. As the workshop ran weekly for 4 weeks, opportunity to see someone more than once who was also a physiotherapist influenced participation. (2) Runners welcomed clarification for online exercises and advice suggested for runners. They were surprised by the difficulty of single-leg neuromuscular facilitation exercises and reported benefit from most or all information especially non-exercise-based approaches such as load management, pain monitoring, and running cues. (3) Participants were empowered by a structured, holistic, and evidence-based approach that embraced autonomy for exercise self-selection and progression. Confidence to engage in open discussion was due to small group size. (4) Barriers to prehab were personal responsibility, equipment, time, lack of supervision, and peer influence. Conclusion: A composite approach to strategies for injury risk reduction during prehab, combining progressive exercises with educational resources, can address runners' individual needs. Early discussion of motivational tools on commencement of prehab with guidance from runners on how to incorporate prehab independently into running training is recommended. Providing these tools allows runners to self-identify the approach best suited to their personal running profile at that given time.
... As running speed increases, the contribution of VL to force production decreases as a function of speed, allowing the hamstrings to provide more force (Monte et al., 2020). On the other hand, pre-activation before ground contact and a more forceful eccentric action have proven to be critical in regulating leg-spring stiffness (Bonacci et al., 2009;Douglas et al., 2020). Although we did not test the muscle pre-activation profile during initial foot contact, previous research indicated that stronger athletes elicited higher pre-activation of the leg extensor muscles compared to weaker counterparts (Kyröläinen and Komi, 1995). ...
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Neuromuscular characteristics, such as lower-limb joint strength and the ability to rapidly generate force, may play an important role in leg-spring stiffness regulation. This study aimed to investigate the relationship between isokinetic knee and ankle joint peak torque (PT), the force-time characteristics of isometric mid-thigh pull (IMTP), and leg stiffness ( K leg )/vertical stiffness ( K vert ) in recreationally trained runners. Thirty-one male runners were recruited and underwent three separate tests. In the first session, the body composition, K leg , and K vert at running speeds of 12 and 14 km⋅h –1 were measured. In the second session, isokinetic knee and ankle joint PT at 60°⋅s –1 were tested. The force-time characteristics of the IMTP were evaluated in the final session. Pearson’s product-moment correlations, with the Benjamini–Hochberg correction procedure, showed that the knee flexor concentric and eccentric and extensor concentric PT ( r = 0.473–0.654, p < 0.05) were moderate to largely correlated with K leg and K vert at 12 and 14 km⋅h –1 . The knee extensor eccentric PT ( r = 0.440, p = 0.050) was moderately correlated with the 14 km⋅h –1 K vert . The ankle plantar flexor concentric and dorsiflexor eccentric PT ( r = 0.506–0.571, p < 0.05) were largely correlated with K leg at 12 km⋅h –1 . The ankle plantar flexor concentric and eccentric and dorsiflexor eccentric PT ( r = 0.436–0.561, p < 0.05) were moderate to largely correlated with K vert at 12 and 14 km⋅h –1 . For IMTP testing, high correlation was only found between the IMPT peak force (PF) and K vert at 14 km⋅h –1 ( r = 0.510, p = 0.014). Thus, superior leg-spring stiffness in recreational runners may be related to increased knee and ankle joint strength, eccentric muscular capacity, and maximal force production.
... Regarding lower limbs' muscle activity measured with EMG during a treadmill test, no differences were found between elite triathletes and runners, finding differences only with less trained athletes in the percentage of individual variance (RMSD%) [58]. In any case, following Bonacci et al. [59], there are differences in leg muscle recruitment between multidisciplinary training and a single disciple. However, it is unknown whether these specific neuromuscular adaptations are beneficial or detrimental to sport-specific performance. ...
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Draft-legal triathlons are the main short-distance races worldwide and are those on which talent-identification programs are usually focused. Performance in these races depends on multiple factors; however, many investigations do not focus on elite triathletes. Therefore, the aim of this narrative review was to carry out a systematic literature search to define the elite female and male triathlete profiles and their competition demands in draft-legal triathlons. This will allow us to summarize the main determinant factors of high-level triathletes as a basis for talent detection. A comprehensive review of Web of Science and Scopus was performed using the search strategy: Triathl* and (performance or competition or profile) and (elite or professional or “high performance” or “high level” or talent). A total of 1325 research documents were obtained, and after screening following the criteria, only 83 articles were selected. After data synthesis, elite triathlete aspects such as age, physiological, anthropometric, and psychosocial profile or competition demands were studied in the scientific literature. Thus, it is essential that when implementing talent identification programs, these factors must be considered. However, constant updating is needed due the continuous regulatory changes and the need of triathletes to adapt to these new competition demands.
... Concluding, the contribution of mechanisms that may affect neuromuscular control and running efficiency, such as the type and age of the athletic shoe, the hardness and the type of surface need further investigation. It is not clear that inadequate recovery from an old injury may be a risk factor for reappearance of a new injury 26 , while the effect of changes in the neuromuscular control, as a result of running injuries, needs to be thoroughly considered 6 . ...
Article
Background: Long distance running is one of the most popular and also one of the most painful sports. As a result of participation in sport is the high incidence of injuries. Most injuries of the long distance runners occur on the lower limb, especially the knee joint. Up to 75% of injuries occur due to overuse by the constant repetition of the same motor pattern. Materials and Methods: This paper is a literature review report concerning the factors leading to lower limb injuries in long distance running. A thorough analysis of relevant literature sources such as articles, studies and books was carried out and is presented. Results: Causative factors associated with injuries to long-distance runners include previous history of injury, lack of experience running and over-week workout. The relationship between injury and risk factors such as warming up, frequency of training, stability of the locomotor pattern running, height of the body, muscle imbalance, limited range of motion, stretching exercises, shoes and quite orthotics devices remains unclear and under investigation. Factors not associated with significant injuries appeared to be age, gender, body mass index, running outdoors or on hard surfaces, participation in other sports, season and time of day. Conclusion: The prevention of sport injuries should focus on changing health behaviors. The health education for injuries should be mainly focused on the importance of full rehabilitation, early recognition of symptoms of overuse and training guidance.
... Beyond the actual movement, it is also apparent that changes in movement patterns have an influence on the subsequent motion kinematics and thus must be highly controlled and regulated by the body and the brain, respectively. Most obvious is the change from a resting situation like sitting to physical activity (Kerr, Durward, & Kerr, 2004;Kerr, Pomeroy, Rowe, Dall, & Rafferty, 2013) or the change between two forms of movement, like from walking to running and back (Diedrich & Warren, 1995;Segers, Aerts, Lenoir, & De Clercq, 2006) or cycling to running in triathlon (Bonacci, Chapman, Blanch, & Vicenzino, 2009;Millet & Vleck, 2000;Weich et al., 2019). Weich et al. (2019) showed in a triathlon study, not only that the transition run after cycling showed deviating behavior over the first minutes of the session, but also from the control condition, an isolated 5000 m run. ...
... However, no study has been found that analyses the efficacy of plyometrics in fatigue conditions. It must be held in mind that the development of resistance is not limited only by the aerobic system but also by characteristics of the neuromuscular system (15)(16)(17). Plyometric training has been shown to generate specific neural adaptations such as an increase in motor unit activation (17)(18)(19). ...
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The transition stage in triathlon effect performance and injury risk. The objective was to determine neuromuscular fatigue induced over 40 km of cycling and the 552 efficacy of plyometric training to combat fatigue and improve performance in the foot race. Twelve triathletes participated, with 5 completing the plyometric training and 7 continuing their normal training. Jump tests were conducted both before and after 40 km of cycling to establish fatigue and pace during the 5 km race was measured. Significant differences were observed in jump height (p<0,05) indicated that 40 km of cycling induces fatigue in the lower extremities. Following plyometric training significant improvements were observed in the Squat Jump test conducted after cycling (p=0.038) and in the pace of the first kilometre (p=0.015). Plyometric training appears to be more efficacious than regular training for reducing neuromuscular fatigue and improving the pace of the first kilometre. RESUMEN Las transiciones en triatlón afectan al rendimiento y riesgo de lesión. El objetivo fue determinar la fatiga neuromuscular inducida por 40 km de ciclismo y la eficacia del entrenamiento pliométrico en la fatiga y rendimiento de la carrera a pie. Participaron doce triatletas, 5 realizaron un entrenamiento pliométrico y 7 continuaron su entrenamiento habitual. Se realizaron tests de salto antes y después de 40 km de ciclismo para determinar la fatiga y se registró el ritmo de 5 km de carrera. Se observaron diferencias significativas en la altura de salto (p<0,05) indicando que 40 km de ciclismo inducen fatiga en la extremidad inferior. Tras el entrenamiento pliométrico se observaron mejoras significativas en el test Squat Jump posterior al ciclismo (p=0,038) y en el ritmo del primer kilómetro (p=0,015). El entrenamiento pliométrico parece ser más eficaz que el entrenamiento habitual para mejorar la fatiga neuromuscular y el ritmo del primer kilómetro.
... Beyond the actual movement, it is also apparent that changes in movement patterns have an influence on the subsequent motion kinematics and thus must be highly controlled and regulated by the body and the brain, respectively. Most obvious is the change from a resting situation like sitting to physical activity [5,6] or the change between two forms of movement, like from walking to running and back [7,8] or cycling to running in triathlon [9][10][11]. Weich et al. [5] showed in a triathlon study, not only that the transition run after cycling showed deviating behavior over the first minutes of the session, but also from the control condition, an isolated 5000 m run. ...
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While training and competing as a runner, athletes often sense an unsteady feeling during the first meters on the road. This sensation, termed as transient effect, disappears after a short period as the runners approach their individual running rhythm. The foundation of this work focuses on the detection and quantification of this phenomenon. Thirty athletes ran two sessions over 60 min on a treadmill at moderate speed. Three-dimensional acceleration data were collected using two MEMS sensors attached to the lower limbs. By using the attractor method and Fourier transforms, the transient effect was isolated from noise and further components of human cyclic motion. A substantial transient effect was detected in 81% of all measured runs. On average, the transient effect lasted 5.25 min with a range of less than one minute to a maximum of 31 min. A link to performance data such as running level, experience and weekly training hours could not be found. The presented work provides the methodological basis to detect and quantify the transient effect at moderate running speeds. The acquisition of further physical or metabolic performance data could provide more detailed information about the impact of the transient effect on athletic performance.
... Regarding aerobic fitness, MAV and EE/session increased in both groups from pre-to post-intervention, evidencing that there was an improvement in physical performance. This could be explained by a neuromuscular adaptation, since repeated practice of exercise is able to increase the control of movement and muscle recruitment patterns 25 . ...
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The purpose of this study was to test if different intensities of aerobic exercise could influence abdominal fat, isoforms of BDNF and executive function. Twenty obese men (30.0 ± 5.4 years old; 34.4 ± 3.5 kg/m²) were randomized to moderate-intensity continuous training (MICT, n = 10) and high-intensity intermittent training (HIIT, n = 10) three times a week for 6 weeks, with isoenergetic energetic expenditure for each exercise session (~ 300 kcal) between conditions. Abdominal fat was assessed pre- and post-intervention; executive function (Coding subtest from BETA-III non-verbal intelligence test and Stroop Color and Word Test), concentrations of mBDNF and proBDNF were assessed in response to acute exercise pre- and post-intervention. Abdominal fat did not change in either group. There was a significant increase in mBDNF immediately after acute exercise in both groups before and after intervention. proBDNF did not present changes acutely nor after 6 weeks. Executive function presented a main effect of time at pre- and post-intervention time-points Stroop Word and Stroop Color and Coding subtest presented improved performance from pre- to post-acute exercise session, in both groups. In conclusion, executive function improvements and acute exercise session-induced increases in mBDNF concentration were found from pre- to post-exercise intervention similarly between MICT and HIIT in obese men.
... The triceps surae contracted and the AT was lengthened at this moment [30]. The repeated "extension-contraction" cycle stimulated the tendon's mechanical properties to improve its ability to load [12,31]. The above theories could be verified by the increased plantarflexion moment and AT force in the study, which indicated that 12-week running with minimalist shoes was an effective way to improve the mechanical properties of AT, i.e., AT force. ...
Article
This study aimed to investigate the effect of a 12-week running program using minimalist shoes on ultrasound-based mechanical adaptation of Achilles tendon (AT). Fifteen male recreational runners accustomed to run in standard cushioned shoes with rearfoot strike pattern were recruited. They were required to wear minimalist shoes without a compulsory transition in foot strike pattern, and be involved in a 12-week running program. Before and after the intervention, the cross-sectional area of AT was collected in the prone position via an ultrasound device. The ankle plantarflexion moment, recorded on an isokinetic dynamometer, was synchronized to the image changes in vivo AT length. Intraclass correlation coefficient was determined to evaluate the intra-and interobserver variabilities. Paired t-test was used to quantify the effects of training program (pre-and post-training) on each variable of the cross-sectional area, AT force, AT stress, and AT strain during an isometric contraction. Seven participants dropped out after the intervention. The results showed that the intraclass correlation coefficients for the intra-and interobserver reliabilities were good to excellent (intraclass correlation coefficients = 0.895-0.996) for the cross-sectional area and elongation. After 12-week running with minimalist shoes, plantarflexion moment, AT force, AT stress, and AT strain significantly increased during an isometric contraction (P < 0.05). The mechanical adaptation of AT improved after 12-week running with minimalist shoes by more efficient energy storage and release, which could prevent or reduce the risk of injury potentially.