Search

This study aimed to investigate the effect of maturity status on force-velocity relationships in a ballistic lower limb (BLL) test in high-level soccer adolescents and young adults. The population was 61 adolescents (13.0–17.9 years) and 23 young adults (18.0–26.2 years). Subjects completed the BLL test on a ballistic ergometer equipped with two force plates and a linear encoder. Following Samozino's method, maximal power output (Pmax), force (F0) and velocity (v0) were determined. An allometric model was applied to Pmax and F0 with body mass (BM) and fat-free mass (FFM). Significant effects of maturity status were found for absolute Pmax, F0, relative Pmax to BM and FFM, relative F0 to FFM and F0 allometrically scaled to BM and FFM (p = 0.02 to p < 0.001; $\eta $ η = 0.10 to $\eta $ η = 0.49). There was no significant effect for Pmax allometrically scaled to BM and FFM, F0 relative to BM and v0. Body dimensions explain group differences in Pmax whereas for F0, qualitative factors explain the differences between the groups. As maturity status and body dimensions influence Pmax, these factors should be considered when assessing explosive short efforts. This could help to better identify potential athletic talent and adapt training content. [ABSTRACT FROM AUTHOR]

Purpose: Delayed structural and functional recovery after a 20 km graded running race was analyzed with respect to the sex effect. Method s : Thirteen female and 14 male recreational runners completed the race and three test sessions: one before (PRE) and two after, once on Day 1 or 2 (D1‐2) and then on Day 3 or 4 (D3‐4). Muscle damage was assessed indirectly using ultrasonography to quantify changes in cross‐sectional area (CSA) of 10 lower‐limb muscles. Delayed onset of muscle soreness (DOMS) was assessed for three muscle groups. Functional recovery was quantified by kinetic analysis of a squat jump (SJ) and a drop jump (DJ) test performed on a sledge ergometer. Linear mixed models were used to assess control group reproducibility and recovery patterns according to sex. Results: Regardless of sex, DOMS peaked at D1‐2 for all muscle groups and resolved at D3‐4. CSA was increased in each muscle group until D3‐4, especially in the semimembranosus muscle. A specific increase was found in the short head of the biceps femoris in women. Regardless of sex, SJ and DJ performances declined up to D3‐4. Depending on the muscle, positive and/or negative correlations were found between structural and functional changes. Some of these were sex‐specific. Conclusion: Structural and functional recovery was incomplete in both sexes up to D3‐4, although DOMS had disappeared. More emphasis should be placed on hamstring muscle recovery. Highlighting the intermuscular compensations that can occur during multi‐joint testing tasks, the structural‐functional relationships were either positive or negative, muscle‐ and sex‐dependent. [ABSTRACT FROM AUTHOR]

Objectives: To identify relevant physiological, mechanical, and strength indices to improve the evaluation of elite mountain bike riders competing in the current Cross-Country Olympic (XCO) format. Methods: Considering the evolution of the XCO race format over the last decade, the present testing protocol adopted a battery of complementary laboratory cycling tests: a maximal aerobic consumption, a force–velocity test, and a multi-short-sprint test. A group of 33 elite-level XCO riders completed the entire testing protocol and at least 5 international competitions. Results: Very large correlations were found between the XCO performance and maximal aerobic power output (r =.78; P <.05), power at the second ventilation threshold (r =.83; P <.05), maximal pedaling force (r =.77; P <.05), and maximum power in the sixth sprint (r =.87; P <.05) of the multi-short-sprint test. A multiple regression model revealed that the normalized XCO performance was predicted at 89.2% (F3,29 = 89.507; r =.95; P <.001) by maximum power in the sixth sprint (β = 0.602; P <.001), maximal pedaling rate (β = 0.309; P <.001), and relative maximal aerobic power output (β = 0.329; P <.001). Discussion: Confirming our expectations, the current XCO performance was highly correlated with a series of physiological and mechanical parameters reflecting the high level of acyclic and intermittent solicitation of both aerobic and anaerobic metabolic pathways and the required qualities of maximal force and velocity. Conclusion: The combination of physiological, mechanical, and strength characteristics may thus improve the prediction of elite XCO cyclists' performance. It seems of interest to evaluate the ability to repeatedly produce brief intensive efforts with short active recovery periods. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the effect of ingesting carbohydrate (CHO), caffeine (CAF), and a guarana complex (GUAc) during a running exercise on cognitive performance, rating of perceived exertion (RPE), and shooting performance in high-level modern pentathlon athletes. Methods: A total of 10 athletes completed 4 counterbalanced sessions within a 2-wk period, corresponding to ingestions of CHO (30 g), GUAc (300 mg), CAF (200 mg), or placebo. The exercise involved a 40-min run on a treadmill at a steady speed, previously determined as a "somewhat hard" exercise (RPE 13). Shooting and cognitive performance (Simon task) were assessed in 3 phases: before exercise and ingestion, before exercise and after half ingestion, and after exercise and full ingestion. Drinks were consumed 40 min (250 mL) and 5 min (125 mL) prior to exercise and after 20 min of running (125 mL). RPE was assessed at 10-min intervals during exercise. Results: There was an interaction between drink and exercise on mean reaction time (P =.01, η p 2 =.41) and a drink effect on RPE (P =.01, η p 2 =.15). CHO, CAF, and GUAc enhanced the speed of information processing after exercise (P =.003, P =.004, and P =.04, respectively), but only CAF and GUAc decreased RPE (P =.002 and P =.02, respectively). Conclusion: The results highlight a beneficial effect of nutritional supplements on information processing and RPE. This finding is particularly interesting as decision-making processes are crucial in the performance of many sports. [ABSTRACT FROM AUTHOR]

PURPOSE: To assess the impact of between-training-sessions recovery strategies (passive [PAS], active [ACT], cold-water immersion [CWI], and ingestion of a recovery drink [NUTR]) on maximal cycling performance, perceptions of delayed-onset muscle soreness (DOMS), and fatigue in world-class BMX riders. METHODS: Eleven elite BMX athletes, members of the French national team (top country in the 2011 international ranking, 4 medals at the 2012 World Championships, top European country), participated in the study, which involved standardized training periods. Athletes performed 3 maximal-sprint power tests: the first day of the week before the training session and before and after training on the third day of the week (D3). The recovery strategy was randomly assigned to each participant on day 2 immediately after the last training period of the day. Perceptions of DOMS and general fatigue were recorded on D3. RESULTS: After training on D3, the decrease in maximal-sprint power (Pmax) was significantly greater for PAS than with CWI (P = .02) and NUTR (P = .018). Similar results were found with ACT (vs CWI P = .044, and vs NUTR P = .042). Self-reported DOMS and fatigue were significantly greater after PAS than after other strategies. CONCLUSIONS: For elite BMX riders, between training days, nutritional and/or CWI recovery strategies appear to be best for reducing muscle fatigue and increasing the capacity to withstand the training schedule. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the influence of serial mouth rinsing (MR) with nutritional supplements on cognitive performance (i.e., cognitive control and time perception) during a 40-min submaximal exercise. Twenty-four participants completed 4 counterbalanced experimental sessions, during which they performed MR with either placebo (PL), carbohydrate (CHO: 1.6 g/25 mL), guarana complex (GUAc: 0.4 g/25 mL) or caffeine (CAF: 67 mg/25 mL) before and twice during exercise. The present study provided some important new insights regarding the specific changes in cognitive performance induced by nutritional supplements. The main results were: (1) CHO, CAF and GUA MR likely led participants to improve temporal performance; (2) CAF MR likely improved cognitive control; and (3) CHO MR led to a likely decrease in subjective perception of effort at the end of the exercise compared to PL, GUA and CAF. Moreover, results have shown that performing 40-min submaximal exercise enhances information processing in terms of both speed and accuracy, improves temporal performance and does not alter cognitive control. The present study opens up new perspectives regarding the use of MR to optimize cognitive performance during physical exercise. [ABSTRACT FROM AUTHOR]