Alain-Steve Comtois

Assessment of gross motor skills and phenotype profile in children 9–11 years of age in survivors of acute lymphoblastic leukemia

The purpose of this study was to evaluate the usefulness of a new gross motor skill test battery in acute lymphoblastic leukemia (ALL) children who have been off therapy for at least 1 year and to assess its discriminatory power (discriminant analysis) from healthy children.

Immersible ergocycle prescription as a function of relative exercise intensity

Purpose The purpose of this study was to establish the relationship between various expressions of relative exercise intensity percentage of maximal oxygen uptake (%VO2max), percentage of maximal heart rate (%HRmax), %VO2 reserve (%VO2R), and %HR reserve (%HRR)) in order to obtain the more appropriate method for exercise intensity prescription when using an immersible ergocycle (IE) and to propose a prediction equation to estimate oxygen consumption (VO2) based on IE pedaling rate (rpm) for an individualized exercise training prescription. Methods Thirty-three healthy participants performed incremental exercise tests on IE and dryland ergocycle (DE) at equal external power output (Pext). Exercise on IE began at 40 rpm and was increased by 10 rpm until exhaustion. Exercise on DE began with an initial load of 25 W and increased by 25 W/min until exhaustion. VO2 was measured with a portable gas analyzer (COSMED K4b2) during both incremental tests. On IE and DE, %VO2R, %HRmax, and %HRR at equal Pext did not differ (p > 0.05). Results The %HRR vs. %VO2R regression for both IE and DE did not differ from the identity line %VO2R IE = 0.99 × HRR IE (%) + 0.01 (r2 = 0.91, SEE = 11%); %VO2R DE = 0.94 × HRR DE (%) + 0.01 (r2 = 0.94, SEE = 8%). Similar mean values for %HRmax, %VO2R, and %HRR at equal Pext were observed on IE and DE. Predicted VO2 obtained according to rpm on IE is represented by: VO2 (L/min) = 0.000542 × rpm2 − 0.026 × rpm + 0.739 (r = 0.91, SEE = 0.319 L/min). Conclusion The %HRR–%VO2R relationship appears to be the most accurate for exercise training prescription on IE. This study offers new tools to better prescribe, control, and individualize exercise intensity on IE.

XP-Antarctik Expedition: The Effect of a Month-Long Expedition in Antarctica on Physiological Performance

Antarctica is a challenging habitat for humans. A group of 6 explorers (3 women and 3 men) participated in an expedition in Antarctica. The objective was to observe the physiological acclimatization of the explorers using the following strategies: physical preparation, highcaloric nutritional intake, and the latest physiological monitoring and outdoor equipment. Anthropometric measures (dual x-ray absorptiometry), specific maximal aerobic test, maximal aerobic running speed test, submaximal aerobic cold testing, strength tests (grip strength, leg press and chin up), and endurance tests (bar suspension and chair position) were conducted preand post-expedition. Due to the sample size, a paired t-test was used for normally distributed data and non-parametric (Wilcoxon) to compare values preand post-expedition. Effect sizes are presented as Cohen’s d. The lean mass for the women was significantly higher after the expedition (45.4 ¡ 4.4 vs. 47.1 ¡ 4.1 kg; p 5 0.040, d 5 1.86); however, no significant difference was observed for the men (66.7 ¡ 7.3 vs. 66.0 ¡ 5.7 kg; p 5 0.581, d 5 0.11). Preand post-expedition values were significantly different for the specific maximal aerobic test, where the VO2peak was 40.8 ¡ 4.2 vs. 46.9 ¡ 7.4 ml/kg/min, respectively (p 5 0.027, d 5 1.01), but no significant difference was observed for the other aerobic tests. The muscular testing did not change significantly, except for the left leg one maximal repetition (295 ¡ 110 vs. 364 ¡ 135 lb, preand post-expedition respectively, p 5 0.031, d 5 20.56). The overall preparation for the expedition appears to be a key aspect in order to countermeasure the physical ability decay during an Antarctica expedition. However, further studies will need to be developed to discern the importance of the preparation components.

Aquatic Exercise Training Outcomes on Functional Capacity, Quality of Life, and Lower Limb Lymphedema: Pilot Study

OBJECTIVE To investigate whether patients with lower limb lymphedema (LLL) can benefit from water immersion exercise training to improve functional capacity, quality of life (QOL), and help control/diminish limb volume. DESIGN A before-after trial. SETTING A community University Sports Center. SUBJECTS Eleven participants were recruited to participate and four declined to pursue the study for personal reasons. A convenient sample of seven female affected by either bilateral or unilateral LLL volunteered for this pilot study. Patients had primary or secondary lymphedema as complications of melanoma or gynecologic cancers. INTERVENTIONS An aquatic training exercise intervention of moderate to vigorous intensity was conducted for a 6-week period (12 sessions of 45 min). This innovative circuit training program consisted of yoga exercises, aqua-jogging, pedaling on a water bike, and muscular training on an aquastep and a trampoline. OUTCOME MEASURES The physical characteristics of water could be used to overcome the physical and medical limitations encountered on dry land for patients with LLL to exercise and reach training benefits. Outcome measures were the 6-min walk test (6MWT), handgrip strength test, QOL for limb lymphedema questionnaire (LYMQOL), bioelectrical impedance spectroscopy, and limb circumference. RESULTS The distance covered in the 6MWT and the handgrip strength were significantly improved. A trend toward an increase in the overall QOL score was noticeable, whereas a significantly improved emotions score was observed with the LYMQOL questionnaire. Limb circumferential volume was significantly lower and impedance was increased, denoting a decrease in lymphatic fluid. CONCLUSIONS Innovative aquatic exercise training program allows moderate and vigorous intensity activities for patients with LLL, increases functional capacity and QOL. Thus, immersion exercise does not appear to exacerbate LLL and a randomized clinical trial with larger numbers is essential to consolidate the results of this study.

Altered Lipid Metabolism Impairs Skeletal Muscle Force in Young Rats Submitted to a Short-Term High-Fat Diet

Obesity and ensuing disorders are increasingly prevalent in young populations. Prolonged exposure to high-fat diets (HFD) and excessive lipid accumulation were recently suggested to impair skeletal muscle functions in rodents. We aimed to determine the effects of a short-term HFD on skeletal muscle function in young rats. Young male Wistar rats (100–125 g) were fed HFD or a regular chow diet (RCD) for 14 days. Specific force, resistance to fatigue and recovery were tested in extensor digitorum longus (EDL; glycolytic) and soleus (SOL; oxidative) muscles using an ex vivo muscle contractility system. Muscle fiber typing and insulin signaling were analyzed while intramyocellular lipid droplets (LD) were characterized. Expression of key markers of lipid metabolism was also measured. Weight gain was similar for both groups. Specific force was decreased in SOL, but not in EDL of HFD rats. Muscle resistance to fatigue and force recovery were not altered in response to the diets. Similarly, muscle fiber type distribution and insulin signaling were not influenced by HFD. On the other hand, percent area and average size of intramyocellular LDs were significantly increased in the SOL of HFD rats. These effects were consistent with the increased expression of several mediators of lipid metabolism in the SOL muscle. A short-term HFD impairs specific force and alters lipid metabolism in SOL, but not EDL muscles of young rats. This indicates the importance of clarifying the early mechanisms through which lipid metabolism affects skeletal muscle functions in response to obesogenic diets in young populations.

Pilot project: Physiologic responses to a high-intensity active video game with COPD patients-Tools for home rehabilitation

Chronic obstructive pulmonary disease (COPD) is a respiratory condition that causes a significant deterioration of the quality of life. However, exercise can improve the quality of life for COPD patients and it is for this reason previous study observed the effects of active video games to increase exercise. Using motion capture devices with short bursts of exercise never been tried with COPD patients.

Acute effects of water immersion on heart rate variability in participants with heart disease

Water immersion and aquatic exercise can be an important therapeutic tool in patients suffering from heart disease (HD). However, the effects of water immersion on heart rate variability (HRV) in HD participants remain unknown.

Acute cardiorespiratory responses in participants with heart disease during cycling at different immersion levels.

Physical activity is often avoided or practised at a low‐intensity level because of the limited ability of patients with heart disease (HD) to provide sustained effort. Immersible training has been suggested as a possible alternative as hydrostatic pressure can modify some hemodynamic parameters in healthy patients and potentially increase the exercise capacity in patients with HD. The purpose of this study was to examine the acute cardiorespiratory adaptations at different levels of immersion using an immersible ergometer (IE) in patients with HD. Twenty‐one patients and 13 healthy controls (HC) participated in this study. Several cardiorespiratory parameters were assessed at two levels of immersion (hips and xiphoid) for five different pedalling rates (40, 50, 60, 70 and peak rpm). At submaximal intensity, HD and HC participants did not differ significantly for most variables. However, for nearly and/or maximal workload, HD participants showed significantly lower values for VO2 and higher values for VE/VO2 and VE/VCO2 for both immersion levels. The increase in immersion level from hips to xiphoid resulted in a significant decrease in VO2 in both HC and HD groups at the same exercise intensity. In addition, the increase in the effects of size values based on the exercise workload indicates that group differences are accentuated with the highest pedalling rates. Our data suggest that participants with HD may benefit from the hydrostatic effect during IE cycling by allowing them to alleviate their submaximal efforts and increasing their maximal cardiorespiratory capacity during hip immersion.

Morphological, Physiological and Skating Performance Profiles of Male Age-Group Elite Ice Hockey Players

Abstract The purpose of this study was to describe the evolution of morphological, physiological and skating performance profiles of elite age-group ice hockey players based on repeated measures spread over one season. In addition, the results of fitness tests and training programs performed in off-ice conditions and their relationship with skating performance were analyzed. Eighteen high level age-group ice hockey players (13.1 ± 0.6 years) were assessed off and on-ice at the beginning and at the end of the hockey season. A third evaluation was also conducted at the beginning of the following hockey season. The players were taller, heavier, and showed bone breadths and muscle girths above the reference population of the same age. Muscular variables improved significantly during and between the two hockey seasons (p < 0.05). However, maximal aerobic power improved only during the off-season. All skating performance tests exhibited significant enhancements during the hockey season, but not during the off-season where some degradation was observed. Finally, weak observed variances (generally <20% of the explained variance) between physiological variables measured off-ice and on-ice skating performance tests indicated important gaps, both in the choice of the off-ice assessment tools as well as in training methods conventionally used. The reflection on the best way to assess and train hockey players certainly deserves to be continued.