Wassim Moalla

Passive versus Active Recovery during High-intensity Intermittent Exercises

PURPOSE To compare the effects of passive versus active recovery on muscle oxygenation and on the time to exhaustion for high-intensity intermittent exercises. METHODS Twelve male subjects performed a graded test and two intermittent exercises to exhaustion. The intermittent exercises (15 s) were alternated with recovery periods (15 s), which were either passive or active recovery at 40% of .VO2max. Oxyhemoglobin was evaluated by near-infrared spectroscopy during the two intermittent exercises. RESULTS Time to exhaustion for intermittent exercise alternated with passive recovery (962 +/- 314 s) was significantly longer (P < 0.001) than with active recovery (427 +/- 118 s). The mean metabolic power during intermittent exercise alternated with passive recovery (48.9 +/- 4.9 mL.kg-1.min-1) was significantly lower (P < 0.001) than during intermittent exercise alternated with active recovery (52.6 +/- 4.6 mL.kg-1.min-1). The mean rate of decrease in oxyhemoglobin during intermittent exercises alternated with passive recovery (2.9 +/- 2.4%.s-1) was significantly slower (P < 0.001) than during intermittent exercises alternated with active recovery (7.8 +/- 3.4%.s-1), and both were negatively correlated with the times to exhaustion (r = 0.67, P < 0.05 and r = 0.81, P < 0.05, respectively). CONCLUSION The longer time to exhaustion for intermittent exercise alternated with passive recovery could be linked to lower metabolic power. As intermittent exercise alternated with passive recovery is characterized by a slower decline in oxyhemoglobin than during intermittent exercise alternated with active recovery at 40% of .VO2max, it may also allow a higher reoxygenation of myoglobin and a higher phosphorylcreatine resynthesis, and thus contribute to a longer time to exhaustion.

Yo-Yo intermittent recovery test versus the Université de Montréal Track Test: relation with a high-intensity intermittent exercise.

The first purpose of this study was to determine whether the peak velocity (V(Yo-Yo)) achieved during the Yo-Yo intermittent recovery test (Yo-Yo) and the maximal aerobic velocity (MAV) determined from the Université de Montréal Track Test (UMTT) could be used interchangeably. The second purpose was to check that the V(Yo-Yo) is related to the intermittent exercise performance, which consisted of repeated 90 m distance runs in 15s performed until exhaustion, alternated with 15s of passive recovery (15/15). Fourteen amateur soccer players performed, in a random order, the 15/15 and two incremental field-tests: the Yo-Yo and the UMTT. The results of this study showed that MAV was significantly correlated to the V(Yo-Yo) (r=0.79, p<0.01). However, the error was not constant, when the V(Yo-Yo) and the MAV values were higher than 16.3 km h(-1), the MAV values tends to be higher than the V(Yo-Yo), while when the V(Yo-Yo) and the MAV values were lower than 16.3 km h(-1), the MAV values tends to be lower than the V(Yo-Yo). MAV and V(Yo-Yo) were significantly correlated to the time to exhaustion of the 15/15 (r=0.74 and r=0.72, respectively) and show that both tests are similarly related to the high-intensity intermittent exercise performance.

Correlation of resistin with inflammatory and cardiometabolic markers in obese adolescents with and without metabolic syndrome.

Objective: The link between plasma resistin and obesity-related cardiometabolic disorders in children remains debatable. This study assessed the relationships of plasma resistin with cardiovascular risk factors, pro-inflammatory markers and insulin resistance index (HOMA-IR) in obese (Ob) adolescents and obese adolescents with metabolic syndrome (Ob-MS) compared to healthy controls (CO). Methods: 114 obese adolescents (60 Ob, age 13.6 ± 0.9 years, BMI 28.0 ± 2.2 kg/m2, and 54 Ob-MS, age 13.8 ± 1.0 years, BMI 32.5 ± 4.8 kg/m2) and 37 CO (age 13.7 ± 0.8 years, BMI 22.8 ± 0.8 kg/m2) were studied. Anthropometrics, cardiac variables as well as fasting plasma concentrations of lipids, glucose, insulin, and adipocytokines (resistin, tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), C-reactive protein (CRP)) were measured. HOMA-IR was calculated, and the presence of MS was assessed. Results: Plasma resistin was significantly higher in Ob-MS than in both Ob and CO and was correlated with anthropometric, cardiovascular, pro-inflammatory markers and several components of MS as was HOMA-IR in Ob and Ob-MS. With increasing the number of MS components, plasma resistin, pro-inflammatory markers, and HOMA-IR were also increased. Multiple regression models highlighted significant correlation between resistin and both HOMA-IR (r = 0.40, p < 0.05) and systolic blood pressure (r = 0.63, p < 0.01) in Ob-MS. Conclusion: These results support the hypothesis that there is an association between circulating resistin and childhood obesity-related inflammatory and cardiometabolic events.

Six-minute walking test and the assessment of cardiorespiratory responses during weight-loss programmes in obese children.

PURPOSE  We assessed the exercise tolerance and cardiorespiratory responses during 2-month weight-loss programmes using the 6-minute walking test (6MWT) in obese children.  METHODS  Twenty-eight male obese children were randomly assigned to either a control group (C), an energy restriction group (R), an exercise training at maximum lipid-oxidation (LIPOXmax) group (E), or an energy restriction/training group (RE). The body composition, the submaximal incremental cycling exercise, and the 6MWT were performed before and after the 2-month programme.  RESULTS . After the programme, RE group showed a significant improvement of body composition (body weight reduced by 6.3 ± 1.5 kg, p < 0.01), and an increase of 6-minute walking distance (6MWD) (+13.7%, p < 0.01). Similarly, maximum oxygen uptake calculated according to the American College of Science Medicine guideline (VO(2max) ACSM) and VO(2max) predicted from 6MWD were respectively higher (+12.9% and +10.0%, p < 0.01) than the R or E groups. Bland-Altman analysis highlighted an agreement of these two methods of VO(2max) measurement. Moreover, in all participants the 6MWD was significantly correlated with VO(2max) ACSM and LIPOXmax (r = 0.77, p < 0.001 and r = 0.67, p < 0.01; respectively) before the programme as well as their changes in percentage over the programme (r = 0.85 and r = 0.86, p < 0.0001; respectively).  CONCLUSIONS  We concluded that a 2-month weight-loss programme including energy restriction and exercise training targeted at LIPOXmax improved body composition and cardiorespiratory tolerance in obese children. Furthermore, the 6MWT could be considered as a useful and reliable tool for the assessment and the follow-up of cardiorespiratory responses during weight-loss programme in obese children.

The acute effect of whole body vibration on repeated shuttle-running in young soccer players.

The aim of this study was to investigate the acute effects of whole-body vibration (WBV) on Repeated Sprint Ability (RSA). Seventeen male soccer players (16.71±0.47 y) performed three RSA tests (Randomized crossover study design). The second RSA test was done with WBV (RSA2) to assess the effect of WBV. The studied variables were: best time (BT), worst time (WT), total time (TT), the fatigue index (FI) of RSA, and post-test blood lactate (BLa). ANOVA with repeated measures showed no differences between RSA1 and RSA3, while there were significant differences in all variables studied. TT= [RSA2 0.93% and 1.68% lower than RSA1 and RSA3 respectively; p<0.05], BLa= [RSA2 16.97% and 14.73% greater than RSA1 and RSA3 respectively; p<0.001], WT= [RSA2 1.90% and 2.93% lower than RSA1 and RSA3 respectively; p<0.01], and FI = [RSA2 30.64% and 40.15% lower than RSA1 and RSA3 respectively; p<0.0001]. When comparing individual sprints, WBV showed a significant effect at the 5th sprint: RSA2 2.29% and 2.95% lower than RSA1 and RSA3 respectively (p<0.005), while at the 6th sprint: RSA2 2.75% and 4.09% lower than RSA1 and RSA3 respectively; p<0.005. In conclusion, when applying WBV during the recovery periods of Repeated Sprint Ability efforts, most of the performance variables improved.

Training effects on peripheral muscle oxygenation and performance in children with congenital heart diseases.

We investigated the effect of training on peripheral muscular performance and oxygenation during exercise and recovery in children with congenital heart diseases (CHD). Eighteen patients with CHD aged 12 to 15 years were randomly assigned into either an individualized 12-week aerobic cycling training group (TG) or a control group (CG). Maximal voluntary contraction (MVC) and endurance at 50% MVC (time to exhaustion, T(lim)) of the knee extensors were measured before and after training. During the 50% MVC exercise and recovery, near-infrared spectroscopy (NIRS) was used to assess the fall in muscle oxygenation, i.e., deoxygenation ([Formula: see text]) of the vastus lateralis, the mean rate of decrease in muscle oxygenation, the half time of recovery (T(1/2R)), and the recovery speed to maximal oxygenation (R(S)). There was no effect of time on any parameter in the CG. After training, significant improvements were observed in TG for MVC (101.6 ± 14.0 vs. 120.2 ± 19.4 N·m, p < 0.01) and T(lim) (66.2 ± 22.6 vs. 86.0 ± 23.0 s, p< 0.01). Increased oxygenation (0.20 ± 0.13 vs. 0.15 ± 0.07 a.u., p < 0.01) and faster mean rate of decrease in muscle oxygenation were also shown after training in TG (1.22 ± 0.45 vs. 1.71 ± 0.78%·s(-1), p < 0.001). Moreover, a shorter recovery time was observed in TG after training for T(1/2R) (27.2 ± 6.1 vs. 20.8 ± 4.2 s, p < 0.01) and R(S) (63.1 ± 18.4 vs. 50.3 ± 11.4 s, p < 0.01). A significant relationship between the change in [Formula: see text] and both MVC (r = 0.95, p < 0.001) and T(lim) (r = 0.90, p < 0.001) in TG was observed. We concluded that exercise training improves peripheral muscular function by enhancing strength and endurance performance in children with CHD. This improvement was associated with increased oxygenation of peripheral muscles and faster recovery.

Relationship between daily training load and psychometric status of professional soccer players

ABSTRACT We studied the relationship between daily training load (TL) experienced by professional soccer players and the Hooper questionnaire reflecting their perceived quality of sleep, fatigue, stress and delayed onset muscle soreness. During a 16-week training period, the rating of perceived exertion and duration were collected after each training session, and daily TL was calculated from 14 professional soccer players. The Hooper questionnaire was completed every day before the first training session and the Hooper’s score (HS) was then calculated. The daily TL and HS were 379.9 ± 198.3 AU and 16.2 ± 5.1, respectively. Pearson correlation showed significant relationships (p < 0.01) between TL and perceived fatigue, muscle soreness, sleep and stress. Our findings revealed that the perceived sleep, stress, fatigue and muscle soreness are moderately related to the daily TL in professional soccer players. The Hooper questionnaire is both a simple and useful tool for monitoring perceived wellness and psychometric players’ status of professional soccer players.

Changes of the psychophysical state and feeling of wellness of professional soccer players during pre-season and in-season periods.

ABSTRACT Perceived changes due to training monotony, strain, sleep, stress, fatigue, muscle soreness and the influence of specific training sessions on the affective valence were explored in professional soccer players. Seventeen players completed the Hooper questionnaire, the ratings of perceived exertion and feeling scale (FS) every training/match day before and during the soccer season. Higher players’ training loads were recorded during pre-season when compared with in-season period (2558.1 ± 262.4 vs. 1642.8 ± 169.3 a.u., p < 0.01; respectively). The ratings of sleep, stress, fatigue and muscle soreness in pre-season were higher than those observed during in-season (p < 0.01) whereas the feeling score was lower (p < 0.01). Furthermore, training sessions, including technical/tactical work, induced an improved feeling score but linked with a lower training load when compared with sessions focus on physical emphasis (p < 0.01). Pre-season period of training induces a significantly more strenuous and exhausting demands on professional soccer players compared with the in-season period at the elite level.

The effects of 8 weeks of motor skill training on cardiorespiratory fitness and endurance performance in children with developmental coordination disorder

Interventions based on everyday motor skills have been developed to be effective in children with developmental coordination disorder (DCD). The purpose of the present study was to examine the effects of motor skill training on exercise tolerance and cardiorespiratory fitness in children with DCD. Children were assigned to 3 groups: an experimental training group comprising 14 children with DCD, a control nontraining group comprising 13 children with DCD, and a control nontraining group comprising 14 typically developed children. All participants were tested twice with an interval of 8-weeks on a cardiopulmonary exercise test, pulmonary function testing, and a 6-min walk test. After the training program the maximal power output was significantly increased for DCD group at anaerobic threshold (p < 0.05) and at peak level (maximal oxygen uptake, p < 0.001). Improvement in power output was more pronounced at the anaerobic threshold (t (13) = -5.21, p < 0.001) than at the maximal intensity (maximal oxygen uptake, t (13) = -3.08, p < 0.01) in the DCD training group. Children with DCD that participated in the training program improved their walking distance (t (13) = -9.08, p < 0.001), had a higher maximum heart rate (t (13) = -3.41, p < 0.01), and reduced perceived exertion (t (13) = 2.75, p < 0.05). The DCD nontraining group and the typically developed group did not change on any of the measures. In conclusion, training delayed reaching the anaerobic threshold and improved aerobic endurance and exercise tolerance in children with DCD.

The effect of a motor skills training program in the improvement of practiced and non-practiced tasks performance in children with developmental coordination disorder (DCD)

The purpose of the present study was to examine the effect of a group-based task oriented skills training program on motor and physical ability for children with DCD. It was also investigated if there was an effect on fine motor and handwriting tasks that were not specifically practiced during the training program. Forty-one children aged 6-10years took part in this study. Children were assigned to three groups: an experimental training group consisting of 14 children with DCD, a control non-training group consisted of 13 children with DCD and a control non-training group consisting of 14 typically developed children. The measurements included were, the Movement Assessment Battery for Children (MABC), the Modified Agility Test (MAT), the Triple Hop Distance (THD), the 5 Jump-test (5JT) and the Handwriting Performance Test. All measures were administered pre and post an 8-week training program. The results showed that 10 children of the DCD training-group improved their performance in MABC test, attaining a score above the 15th percentile after their participation in the training program. DCD training-group showed a significant improvement on all cluster scores (manual dexterity (t (13)=5.3, p<.001), ball skills (t (13)=2.73, p<.05) and balance (t (13)=5.13, p<.001). Significant performance improvements were also found in MAT, THD, 5JT (t (13)=-4.55; p<.01), handwriting quality (t (12)=-2.73; p<.05) and speed (t (12)=-4.2; p<.01) after the training program. In conclusion, improvement in both practiced and non-practiced skills, in the training program, may reflect improvement in motor skill but also transfer to other skills.