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Context: Recent research has underpinned the occurrence of nonlocal exercise effects. For instance, self-myofascial release (SMR) of the plantar fascia increases hamstring extensibility. A possible mechanism consists in a mechanical force transmission across myofascial chains. However, as the degree of structural continuity in these chains decreases with age, the magnitude of the above described remote effects might also be reduced throughout a lifespan. Objective: To examine the age dependency of nonlocal exercise effects following plantar fascia SMR. Design: Regression experimental study. Setting: General population. Participants: 168 healthy participants (Mage = 45 [21 ] y, 85 males). Intervention: One 120 s bout of plantar foot SMR, performed in standing position. Main Outcomes Measure: Hamstring extensibility was assessed using sit and reach testing. Relative prepost differences were classified as no improvement, clinically nonrelevant improvement, or clinically relevant improvement according to previously published data. The age dependency of the effects was calculated by means of multinomial stepwise logistic regression. If the latter revealed other factors than age to affect treatment effectivity, their effect was eliminated using partial correlation. Results: SMR increased hamstring extensibility by 10.1% (pre: 24.9 [9.7] cm, post: 27.4 [9.3] cm, P< .001). About 99 participants (58.9%) attained a clinically relevant change. Multinomial logistic regression demonstrated no influence of sex, amount of physical activity, height, body mass index, and time of day, but a significant impact of baseline flexibility and age (Nagelkerke's r² = .32, P< .001). Post hoc partial correlation analysis demonstrated that age, corrected for baseline flexibility, had a small to moderate association with treatment effectivity (r=. 29, P < . 001). Conclusions: Plantar foot SMR increases hamstring extensibility, which is explained by age to a small degree. Additional research is warranted to delineate the substrate of remote exercise effects. Besides mechanical force transmission, cortical adaptations might also represent the driving factor. [ABSTRACT FROM AUTHOR]

We tested if ACL-reconstructed participants show a decreased quadriceps torque, a lower muscle endurance capacity and a higher peak torque variability compared to unimpaired control participants prior to and following local muscle fatigue. Participants (n = 19, 10 women; 25 ± 5yrs.) with unilateral hamstrings autograft ACL-reconstruction and a matched unimpaired control group were recruited. Participants performed two maximal isometric voluntary force (MIVF) contractions of the knee extensors. In between, standardized local muscle fatigue was induced. ACL-reconstructed knees display a lower peak torque of the knee extensors in comparison to the contralateral limb (3.2 ± .3Nm/kg vs. 3.5 ± .3 Nm/kg). Peak torque variability and fatigue resistance were not affected by local muscle fatigue (p > .05). Participants with ACL-reconstructed knees show a persistent quadriceps muscle dysfunction. This dysfunction and lower limb side asymmetries might be risk factors for ACL re-ruptures. [ABSTRACT FROM AUTHOR]

Purpose: A small share of the world's population meets current physical activity guidelines, which recommend regular engagement in endurance, strength, and neuromotor exercise. As lack of time represents a major cause of inactivity, multidimensional training methods with short durations may provide a promising alternative to classical, volume‐oriented approaches focusing on one biomotor ability. This trial examined the effects of a high‐intensity functional circuit training (HIFCT) on motor performance and exercise motivation in untrained adults. Methods: Thirty‐three inactive participants were randomly allocated to two groups exercising for six weeks. The intervention group (HIFCT, n = 20) 3×/week performed functional whole‐body exercises in a circuit. Each 15‐minute workout included repetitive 20s all‐out bouts with 10s breaks. In the comparison group (moderate aerobic exercise, MAE, n = 13), the participants walked 3×/week for 50 minutes at moderate intensity. Measured motor outcomes were cycling endurance capacity (respiratory threshold, maximum workload), maximum strength (leg and chest press), postural control (force plate), and jump capacity (counter‐movement jump, single leg hop for distance); exercise motivation was assessed using the self‐concordance index. Results: In comparison with MAE, HIFCT enhanced maximum leg strength (between‐group difference of relative pre‐ to post‐changes of 5.0%), shoulder strength (7.6%), and endurance workload (5.0%; P < 0.05), while increasing motivation to exercise (+5.5 points, P < 0.05). No between‐group differences occurred for postural control and jump capacity (P > 0.05). Conclusion: Despite considerably shorter training duration, HIFCT enhances motor function and motivation to exercise more effectively than MAE. Further research should investigate the long‐term adherence to the program and its effectiveness in other settings. [ABSTRACT FROM AUTHOR]