Due to drawbacks of the percentage-based approach, velocity-based training was proposed as a method to better and more accurately prescribe training loads to increase general and specific performance. The purpose of this study was to perform a systematic review of the studies that show effects of velocity-based resistance training on strength and power performance in elite athletes. Electronic searches of computerized databases were performed according to a protocol that was agreed by all co-authors. Four databases—SportDiscus with Full Text and MEDLINE via EBSCO, SCOPUS, and Web of Science—were searched. Seven studies were found which researched the effects of velocity-based resistance training on athletes after a given training period. The analyzed studies suggest that applying velocity losses of 10–20% can help induce neuromuscular adaptations and reduce neuromuscular fatigue. Using velocity zones as part of a separate or combined (e.g., plyometric) training program can elicit adaptations in body composition and performance parameters. Moreover, velocity zones can be programmed using a periodized or non-periodized fixed velocity zones protocol. Lastly, obtaining instantaneous feedback during training is a more effective tool for increasing performance in sport-specific parameters, and should be used by sport practitioners to help keep athletes accountable for their performance.

Background. The aim of the study was to evaluate differences in body image across different types of sports in highly trained female athletes. Methods. 242 female individuals, aged 13–30 years (M=20.0, SD = 4.5), representing aesthetic sports (n=56) and nonaesthetic sports (n=186), were recruited from different sports clubs in Poland. Body image, BMI, age, the level of competition attained, and the training background of participants were recorded. Results. One-way ANOVA showed differences in the body image of athletes engaged in different types of sport (F(11,230)=4.10, p<0.001, and η2=0.16). The model predicting the body image of female athletes was significant (F(5,236)=10.40, p<0.001); the adjusted R2=0.163. Type of sport explained 7.1% (β=–0.263, p<0.001), age explained 4.5% (β=0.341,p<0.001), BMI explained 3.6% (β=–0.230,p<0.001), and level of competition explained 0.9% (β=0.153, p<0.05) of variance in body image. Conclusions. The findings provide vital new knowledge which can be used by researchers and practitioners in designing educational programs on weight-related behaviors in female athletes. Such programs should be implemented especially in young female athletes participating in high-level sporting activities at an early stage.

The aim of the study was to investigate the relationship between body image and prevalence of underweight, normal weight, and overweight in adolescents. The study included 1702 girls and 1547 boys, aged 14–16 years, who completed questionnaire assessing body satisfaction. The participants’ BMI status: underweight, normal weight or overweight was determined on the basis of BMI cut-off values. Results revealed that more girls (p < .001) showed low body satisfaction (44.8%) and fewer girls (p < .001) had high body satisfaction (17.6%) compared to boys (28.5% and 29.0%, respectively). A two-way ANOVA revealed a significant interaction between BMI status and gender on body satisfaction F(2, 3243) = 4.10, p = .017, η² = .003. In boys, body satisfaction was higher in normal weight and underweight in comparison to overweight individuals (p < .001). Underweight girls presented higher body satisfaction than those who were normal weight and overweight (p < .001). Our findings indicated that, in relation to gender, BMI status can be associated with different body satisfaction in adolescents. This should be taken into consideration when designing programs aimed at obesity and disordered eating prevention and body image improvement. Due to the fact that underweight girls and boys have high body satisfaction, this can lead to behaviors that maintain low body weight in adolescents and in turn this may have negative health consequences.

Reduced nicotinamide adenine dinucleotide (NADH) is synthesized in the cellular nucleus, cytoplasm and mitochondria but oxidized into NAD⁺ almost exclusively in mitochondria. Activation of human skin by the 340 nm ultraviolet light triggers natural fluorescence at the light length of 460 nm, which intensity is proportional to the skin NADH content. This phenomenon is used by the Flow Mediated Skin Fluorescence (FMSF) which measures changes in the skin NADH content during transient ischemia and reperfusion. We examined the effects of exercise to exhaustion on the skin changes of NADH in response to 200 s forearm ischemia and reperfusion in 121 highly trained athletes (94 men and 27 women, long-distance running, triathlon, taekwondo, rowing, futsal, sprint running, fencing, and tennis). We found that exercise until exhaustion changes the skin content of NADH, modifies NADH turnover at rest, during ischemia and reperfusion in the most superficial living skin cells. Compared to the pre-exercise, there were significant increases in: mean fluorescence recorded during rest as the baseline value (B_mean) (p < 0.001), the maximal fluorescence that increased above the baseline during controlled forearm ischemia (FI_max) (p < 0.001, only in men), the minimal fluorescence after decreasing below the baseline during reperfusion (FR_min) (p < 0.001 men; p < 0.01 women) and the difference between B_mean and FR_min (R_min) (p < 0.01), and reductions in the difference between FI_max and B_mean (I_max) (p < 0.001) and I_max/IR_ampl ratio (CI_max) (p < 0.001) after the incremental exercise test. There was no statistical difference between pre- and post-exercise the maximal range of the fluorescence change during ischemia and reperfusion (IR_ampl)_. In conclusion, exercise to exhaustion modifies the skin NADH content at rest, during ischemia and reperfusion as well as the magnitude of changes in the NADH caused by ischemia and reperfusion. Our findings suggest that metabolic changes in the skin NADH accompanying exercise extend beyond muscles and affect other cells and organs.