ECSS Paris 2023: CP-BM15
INTRODUCTION: The literature on the effect of fatigue on motor learning is limited and marked by inconsistent findings, likely due to significant variability in methodologies. This scoping review aimed to explore the available knowledge on the effects of fatigue induced by physical and mental exertion on motor learning. Specifically, this review sought to investigate: 1) how fatigue and motor learning were defined, 2) the methods used to induce and quantify fatigue, 3) the methods used to assess motor learning, and 4) the target populations that have been investigated. METHODS: A pre-registered comprehensive search was conducted in 8 databases. The included studies had to apply a fatiguing protocol performed during the same session as the motor learning task and include at least one criterion to verify the successful fatigue induction. Studies were included if they involved practicing a motor learning task. All types of fully published peer-reviewed articles and gray literature were eligible for inclusion. The language was restricted to English and French. RESULTS: The initial database search returned 1887 references, of which 36 full texts met the inclusion criteria. An additional article was identified through forward citation searching. In total, 21 sources were included: 19 primary sources and 2 secondary sources (1 MSc thesis and 1 book chapter). Results from the 19 primary sources revealed that only 1 study included definitions for both fatigue and motor learning. Fatigue induced by physical exertion was the most frequently used method across studies, accounting for 84% of cases. Fatigue induced by mental exertion was employed in only 16% of the studies. No study employed a combined mental and physical exertion method to induce fatigue. Motor acuity was the most frequently used paradigm to infer motor learning, accounting for 53% of the studies. Adaptation and sequence learning paradigms accounted for 26% and 21% of the studies, respectively. No association paradigm was employed to infer motor learning. All participants were aged 19-31 years old. Of all the studies, 47% reported participants sex and 42% reported participants’ gender. None of the studies included information about participants ethnicity. CONCLUSION: This review underscores the critical need for clear, operational definitions of both fatigue and motor learning to enhance measurement consistency and reproducibility. Given the limited research on the effects of fatigue induced by mental and combined exertion, future studies should prioritize using these types of experimental manipulations to induce fatigue. Additionally, exploring adaptation, sequence learning, and association paradigms could provide deeper insights into how fatigue influences motor learning. Future studies should expand their participant pools to include middle-aged and older adults as well. Moreover, reporting key participant characteristics such as sex, gender, and ethnicity should be prioritized.
Read CV Bahram Ghafari GousheECSS Paris 2023: CP-BM15
INTRODUCTION: Prolonged standing can cause neuromuscular fatigue, tissue swelling, and subjective fatigue in the legs (1). However, few studies have investigated recovery strategies for these symptoms. Carbon dioxide (2) and menthol (3) have been shown to improve peripheral circulation when applied transdermally and may serve as promising treatments for fatigue and swelling. We thus aimed to determine individual and combined effects of carbon dioxide and menthol on the recovery from prolonged standing. METHODS: Thirteen healthy adults (7 men and 6 women) participated in this study. The participants first underwent 70 minutes of quiet standing and then rested in a seated position for 30 minutes with a gel sheet (12.5 x 8.5 cm) applied to the posterior aspect of both lower legs. Four types of gel sheets were tested in a randomized order on separate days: placebo (P), carbon dioxide (C), menthol (M), and a combination of carbon dioxide and menthol (CM). Ankle dynamometry combined with tibial nerve stimulation, surface electromyography, near-infrared spectroscopy, bioelectrical impedance analysis, and ultrasonography were used to comprehensively evaluate neuromuscular function and morphology in the lower leg before and after standing and after recovery. Subjective fatigue was assessed using a visual analog scale. One-way ANOVA was performed to test whether changes in each variable differed between conditions. A generalized linear mixed model was used to examine how the change in subjective fatigue was related to those in selected physiological variables. RESULTS: No significant differences between gel sheets were observed for changes in heart rate, lower leg skin temperature, volume, extracellular water ratio, electromyographic activity of soleus (Sol) and medial gastrocnemius (MG) during maximum voluntary contraction, or subjective fatigue. CM more effectively reduced electromechanical delay, deoxygenated hemoglobin, circumference, and muscle hardness than did P, while increasing twitch force, maximum isometric torque production, voluntary activation, rate of torque development, and Sol and MG activity at 0-200 ms (p < 0.05, Tukey HSD test). C more effectively reduced muscle hardness and increased MG activity than P. M had no significant effect compared with P. The recovery of subjective fatigue was linked to the recovery of lower leg circumference, rate of torque development, and Sol activity. CONCLUSION: Our results provide the first evidence that compared with the individual application, the simultaneous application of carbon dioxide and menthol markedly restores leg muscle function impaired by prolonged standing. The recovery of subjective fatigue was apparent even with the placebo application but may be partly attributed to improvements in peripheral circulation and neuromuscular function. REFERENCES: 1) Wall et al., Ergonomics, 2020 2) Ogoh et al., Physiol Rep, 2016 3) Craighead et al., Microvasc Res, 2016
Read CV Shohei KimuraECSS Paris 2023: CP-BM15
INTRODUCTION: Resistance training is hardly recommended for postmenopausal women to counteract negative effects of hormonal changes (1). Furthermore, OMS guidelines include the recommendation of different levels of strength training depending on age. It has been demonstrated that set configuration can modulate velocity and power loss causing different levels of fatigue (2), but this topic has been mainly investigated in healthy and young people. The objective of this study was to compare de effects of set configuration on mechanical performance in leg press exercise of postmenopausal women. METHODS: 50 physically active postmenopausal women participated in this study funded by the Spanish Ministry of Science, Innovation and University (PID2021-124277OB). After a medical exam and familiarization, women completed in a randomized order 3 experimental sessions differing in set configuration: 9 sets of 4 reps with 45s of inter-set rest; 6 sets of 6 reps with 72s of inter-set rest and 4 sets of 9 reps with 120s inter-set rest. They completed a total of 36 reps per exercise with 12RM load (i.e., leg press, bench press, prone leg curl and lat pull-down). Resting time between exercises was 4 min. Throughout leg press performance mechanical data (i.e. velocity and power loss) was collected. Blood lactate concentration samples (La) were obtained before and 1min after session. Explosive performance was also evaluated before and after each session by 2 reps at maximum intended velocity with 70% of 12RM in leg press exercise. RESULTS: Regarding the percentage of velocity and power loss, a main effect of session (p<0.001) was found with significant greater losses in 6S and 9S compared with 4S for both variables. La after session was significantly higher than before for all sessions, with greater values in 9S compared to 6S and 4S (9S>6S>4S) (p>0.001). For neuromuscular test, main effect of session (p=0.035) and time (p<0.001) with no interaction (p=0.266) was found, suggesting the same velocity reductions in the explosive test for all set configurations. CONCLUSION: Set configuration modulated the mechanical performance of postmenopausal women in leg press exercise in terms of mechanical performance. Short configurations (i.e.,4S) allow to reduce the loss of velocity and power in leg press during training sessions with low lactate values, which helps preserve movement quality and may increase exercise adherence by reducing the effects of delayed onset muscle soreness. References 1. Hulteen RM, Int J Sports Med, 2023 2. Rial-Vázquez J, Sport Biomech. 2020
Read CV Juan FariñasECSS Paris 2023: CP-BM15