Background: The obesity epidemic among adolescents significantly impacts not only their physical health but also various psychological factors, including their perception of body image. Thus, this study pursued three main objectives: (1) to update the reference standard values for all the physical fitness tests performed; (2) to examine the impact of overweight and obesity on factors influencing physical fitness in adolescents; and (3) to determine the relationship between the physical fitness level and the body image dissatisfaction among a population of French-Canadian adolescents. Methods: A total of 1862 adolescents aged 12 to 17 (1008 boys and 854 girls) participated in this study. Data were collected from 12 French-language high-schools from different socioeconomic backgrounds and spread across four regions of the province of Québec, Canada. Anthropometric measures (body mass, body height, body mass index (BMI), waist circumference, waist-to-height ratio) and fitness tests (aerobic power, anaerobic power, muscle endurance, muscular power, flexibility) were conducted. To assess adolescents’ body perception, a silhouette scale was used. Results: Standardized normative values were established for each fitness test (Lambda Mu Sigma; LMS method). In boys, performance generally improved with age, except for the V-test and sit-ups, which remained stable, and VO2peak, which declined during adolescence in both genders (unpaired t-test and Cohen’s d effect size). In girls, only the vertical jump and 30 m sprint improved with age, while the other tests stabilized by age 13. Fitness level was significantly influenced by obesity status. Boys and girls with a normal BMI performed better than those who were overweight or obese (ANOVA = p < 0.001 and effect size F). Girls appeared to be less affected by obesity status, with differences between overweight and obese groups rarely being significant (p > 0.05). Fitness level was also linked to body satisfaction, with satisfied adolescents generally achieving better scores than dissatisfied ones, even among those with a typical BMI. Socioeconomic status did not impact body image perception in boys (p = 0.351). In contrast, girls from lower socioeconomic backgrounds exhibited significantly more negative perceptions (p = 0.002) than their peers from more affluent families. Conclusions: Obesity status is strongly associated with poorer performance on fitness tests. Conversely, higher levels of physical fitness are linked to improved body image satisfaction. This positive relationship between fitness and body image holds true even for individuals with a healthy body weight (typical BMI).

The lack of specific on-ice tests to predict maximum lactate concentration limits the ability of coaches to better track and develop their ice hockey players. Thus, this study aimed to develop an equation for indirectly assessing the maximum lactate concentration produced from an all-out on-ice skating effort in elite adolescent ice hockey players. Twenty elite male ice hockey players participated in this study (age = 15.7 ± 1.0 year). The lactate anaerobic skating test (LAST) consisted of skating back and forth on an 18.2 m course at maximal speed with abrupt stops at each end for a total of 6 shuttles (total distance = 218.2 m; average time = 52.0 ± 2.0 s). The oxygen uptake was measured using a portable metabolic analyzer (Cosmed K4b 2) and the maximum post-exercise lactate concentration with a Lactate Pro analyzer. The variables used to estimate lactate concentration were time, heart rate, number of skating strides in the last shuffle (6 th) and the skating stride index. The average maximum lactate concentration was 14.4 mmol· L −1 , which is expected in elite players. The analysis of explained common variance using T-test (r² = 0.759) and linear regression (r² = 0.863) demonstrates the validity of the model. Additionally, the root mean square error (RMSE = 0.60 mmol· L −1), the mean absolute error (MAE = 0.45mmol· L −1) and the standard error of estimate (SEE = 0.69 mmol· L −1) values further confirm the accuracy of the model. Thus, using simple and easy-to-measure variables (i.e., time and skating stride), coaches will be able to monitor more effectively their players' progress in an effort to optimize their individual on-ice performance.

Objective: The main objective of this study was to examine secular trends in body mass, body height and body mass index (BMI) from measured rather than self-reported values between 1972 and 2017. Methods: A total of 4500 students (males = 51%) were selected from a stratified sampling. The age range varied between 6.0 and 17.9 years. The sample came from 24 elementary schools and 12 high schools located in six urban cities from the province of Québec. All the tests selected were based on standardized procedures that are recognized as valid and reliable. Standardization and modeling of smoothed percentile curves for each variable for both sexes were produced. Results: Regional variations between youth from the province of Québec and those from all other Canadian provinces confirm the relevance of using data specific to the target population. Comparisons with the 1972 and 1982 data show an important increase in body mass (~ 7 kg, i.e. 16.4%) and BMI (~ 1.4 kg·m-2, i.e. 19.9%) with minor change in body height (~ 1.8 cm, i.e. 3.9%). Youth from low-income backgrounds (p = 0.001) as well as those living in large urban cities (p = 0.002) see their probability of developing overweight or obesity greatly increase (low-income = 2.1 times; large urban cities = 1.3 times). However, overweight and obesity rates seem to have stabilized at around 21% since 2004. Conclusion: This study provides up-to-date data on factors that contribute to the prevalence of overweight and obesity in youth in urban settings of Québec, and will be instrumental in guiding public health strategies designed to optimize growth outcomes.

Background In the context of concerns regarding the cardiorespiratory fitness (CRF) of youth populations, the aims of this study were: (1) to update reference values for the VO2max for school-aged Canadians and (2) to document secular trends in CRF after a 35-year interval. Methods Between September 2014 and April 2017, the CRF of 3725 students (53.2% boys; 6.0 to 17.9 yrs) was determined using the 20-m shuttle run test. The sample was collected in 36 different schools from six cities of Québec (Canada). Results Median values of VO2max decreased with age in both sexes (p ≤ 0.05). By the age of 10, more than 20% of boys showed VO2max values below the recommended value (42 ml·kg⁻¹·min⁻¹). At the age of 17, that proportion reached 56.8%. A similar proportion of 12 yrs girls (20%) were under the recommended minimal value (37 ml·kg⁻¹·min⁻¹) and that value reached 69.9% at the age of 17. Compared to 1982, the VO2max at age 17 has declined by 18% for boys and 12% for girls. The situation is worse in terms of functional capacity (number of stages completed) with an overall decrease of more than 30%. Conclusion This study demonstrates that, compared to data obtained using the same methodology 35 years ago, the CRF and functional capacity of children and adolescents has declined to levels that should raise concerns from a public health perspective. Thus, the development of strategies to promote a physically active lifestyle in youth is more relevant than ever.

This study compared the absolute (kg) and relative (Wilks pts) maximal strength (MS) gains between the accommodated resistance (AR) and the classic plate loaded (CPL) training methods. Seventeen (17) powerlifters were separated into two groups [experimental (EG; n=9) and control (CG; n=8)]. Both followed the same 9-week, 4 times a week, 2 hour, wave-like percentage-based training program with pre and post MS powerlifting testing measures except that the EG trained with a 25% added AR (elastic bands or chains) and 80% of the CPL bar weight. Elastic band resistance relative to bar height for all powerlifting movements was measured with a stadiometer. A two-way repeated measure ANOVA was performed. Effect sizes (ES) were calculated with Morris’ estimate effect size. The EG significantly (p<0.05) improved more in the Deadlift Wilks pts and Total Wilks pts (+6.3±3.9% vs 0.1.±5.9%; ES=0.55 and 6.3±5.1% vs 2.1±2.3%; ES=0.24 respectively), that the EG trended (p>0.05) towards improving more in the Squat Kg (+6.5±9.7% vs 2.8±3.0%; ES= 0.04), Squat Wilks pts (+9.5±11.6% vs 2.9±3.2 %; ES=0.21), Deadlift Kg (3.5±3.7% vs 0.0±5.4%; ES=0.19) and Total Kg (3.4±3.5% vs 2.0±2.4%; ES=0.03). In contrast, the CG trended (p>0.05) towards improving more in the Bench Kg (4.3±3.5% vs -0.1±6.9%; ES=-0.16) and Bench Wilks pts (4.3 ± 4.0 % vs 2.6±7.5%; ES=0.1). Thus, the present AR technique produces significantly greater relative MS gains when prescribing deadlifts twice a week, non-significant greater MS gains when prescribing squats twice a week, but CPL produces non-significant greater MS gains when prescribing presses four times a week.