Peak oxygen uptake (V̇O2peak) is routinely expressed in litres per minute and by unit of body mass (mL·kg(-1)·min(-1)) despite the theoretical and statistical limitations of using ratios. Allometric modeling is an effective approach for partitioning body-size effects in a performance variable. The current study examined the relationships among chronological age (CA), skeletal age (SA), total body and appendicular size descriptors, and V̇O2peak in male adolescent roller hockey players. Seventy-three Portuguese, highly trained male athletes (CA, 15.4 ± 0.6 years; SA, 16.4 ± 1.5 years; stature, 169.9 ± 6.9 cm; body mass, 63.7 ± 10.7 kg; thigh volume, 4.8 ± 1.0 L) performed an incremental maximal test on a motorized treadmill. Exponents for body size descriptors were 2.15 for stature (R(2) = 0.30, p < 0.01) and 0.55 for thigh volume (R(2) = 0.46, p < 0.01). The combination of stature or thigh volume and CA or SA, and CA(2) or SA(2), increased the explained variance in V̇O2peak (R(2) ranged from 0.30 to 0.55). The findings of the allometric model combining more than 1 body size descriptor (i.e., stature and thigh volume) in addition to SA and CA(2) were not significant. Results suggest that thigh volume and SA are the main contributors to interindividual variability in aerobic fitness.

29Aristides Machado-Rodrigues [rodriguesari@hotmail.com] The study was aimed to investigate the reproducibility of performance parameters obtained 4 from 10-s sprints against different braking forces in young adult athletes. The sample (n=48) 5 included male athletes aged 18.9-29.9 years (175.5±6.9 cm, 76.2±10.1 kg). The 10-s 6 maximal exercise was performed in a cycle-ergometer against a random braking force (4% to 7 11% of body mass). Intra-individual variation was examined from repeated tests within one 8 week. Descriptive statistics were computed and differences between sessions tested using

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The use of saliva to monitor immune and hormonal responses in training, competitions, and during recovery is an easy and non-invasive alternative means of collecting samples compared to serum collection. Saliva can provide insight into a number of interesting biomarkers such as cortisol, testosterone, immunoglobulins, alpha-amylase, and melatonin, among others. High-intensity and exhaustive exercises, such as training or competition, provide variations in immune, protein and hormonal markers. An adequate recovery period, calming down, and recovery methods can contribute to a fast normalization of these markers, decreasing illness, as well as the likelihood of overtraining and injuries, but their effectiveness is still inconclusive. The aim of this review was to investigate the evidence of salivary markers in post-exhaustive exercise during the recovery period. This study is a systematic review from three electronic databases with studies from 2011 to 2021 within healthy humans. The search found 213 studies, and after applying the inclusion and exclusion criteria, while excluding duplicated studies, 14 studies were included in this review. The most cited salivary markers were cortisol and testosterone, as well as their ratio, alpha-amylase and IgA. Half of the studies applied a variety of recovery methods that showed controversial results over salivary markers’ impact. However, they showed an impact on the markers from the exercise, which was still dependent on exercise intensity, methodology, and duration.

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Canoe paddling requires an asymmetric muscular work that predisposes athletes to musculoskeletal imbalances. Ten elite athletes were analyzed in three phases: 1) assessment of the postural and anthropometric corporal profile through the biophotogrammetry technique; 2) simulation of parameterized ergometer tests to determine the effectiveness of a suggested innovative active recovery method in body rebalancing and 3) thermographic analysis of the musculoskeletal profile. Canoe practice demonstrated leading to important corporal changes and, since there is no decrease in performance with the suggested recovery method, it was concluded that would be useful to implement the paradoxical paddling as a practice of the canoeists daily training, making a healthy symbiosis between recovery and postural compensation at sportive and medical level

In recent years, there has been an exponential increase in the number of devices developed to measure or estimate physical exercise. However, before these devices can be used in a practical and research environment, it is necessary to determine their validity and reliability. The purpose of this study is to test the validity and reliability of a load cell sensor-based device (LC) for measuring the peak force (PFr) and the rate of force development (RFD) during the isometric mid-thigh pull (IMTP) test, using a force plate (FP) as the gold standard. Forty-two undergraduate sport science students (male and female) participated in this study. In a single session, they performed three repetitions of the IMTP test, being tested simultaneously with an LC device and a Kistler force platform (FP). The PFr and RFD data were obtained from the force-time curve of the FP and compared with the LC data, provided automatically by the software of the device (Smart Traction device©). The mean difference between the results obtained by the LC device and the gold-standard equipment (FP) was not significantly different (p > 0.05), for both PFr and RFD, which suggests the validity of the ST results. Bland–Altman analysis showed a small mean difference in PFr = 1.69 N, upper bound = 47.88 N, and lower bound = −51.27 N. RFD showed that the mean difference was −5.27 N/s, upper limit = 44.36 N/s, and lower limit = −54.91 N/s. Our results suggest that the LC device can be used in the assessment of the isometric-mid-thigh-pull test as a valid and reliable tool. It is recommended that this device’s users consider these research results before putting the ST into clinical practice.

OBJECTIVES:The aim of this study was to examine the concurrent contributions of body size, estimates of whole-body composition, and appendicular volume in addition to participation in competitive basketball to explain inter-individual variance in anaerobic peak power output during late adolescence. The study also tested non-participation versus participation in basketball as an independent predictor of peak power output. METHODS: The sample of this cross-sectional study was composed of 63 male participants (basketball: n=32, 17.0±0.9 years; school: n=31, 17.4±1.0 years). Anthropometry included stature, body mass, circumferences, lengths, and skinfolds. Fat-free mass was estimated from skinfolds and lower limbs volume predicted from circumferences and lengths. Participants completed the force-velocity test using a cycle ergometer to determine peak power output. RESULTS: For the total sample, optimal peak power was correlated to body size (body mass: r=0.634; fat-free mass: r=0.719, lower limbs volume: r=0.577). The best model was given by fat-free mass and explained 51% of the inter-individual variance in force-velocity test. The preceding was independent of participating in sports (i.e., the dummy variable basketball vs. school did not add significant explained variance). CONCLUSION: Adolescent basketball players were taller and heavier than school boys. The groups also differed in fat-free mass (school: 53.8±4.8 kg; basketball: 60.4±6.7 kg), which was the most prominent predictor of inter-individual variance in peak power output. Briefly, compared to school boys, participation in basketball was not associated with optimal differential braking force. Higher values in peak power output for basketball players were explained by a larger amount of fat-free mass.