Richard J. Winsley

Prevalence of Nonfunctional Overreaching/Overtraining in Young English Athletes

PURPOSE Nonfunctional overreaching and overtraining (NFOR/OT) in adults can lead to significant decrements in performance, combined with physical and psychological health problems. Little is known about this condition in young athletes by comparison; thus, the aim of the study was to assess the incidence and symptomatology of NFOR/OT in young English athletes. METHODS Three hundred seventy-six athletes (131 girls and 245 boys, age=15.1±2.0 yr) completed a 92-item survey about NFOR/OT. The sample included athletes competing at club to international standards across 19 different sports. Athletes were classified as NFOR/OT if they reported persistent daily fatigue and a significant decrement in performance that lasted for long periods of time (i.e., weeks to months). Data were analyzed using the Mann-Whitney U and the Kolmogorov-Smirnov nonparametric tests. Significant predictors of NFOR/OT were identified using logistic regression analysis. RESULTS One hundred ten athletes (29%) reported having been NFOR/OT at least once. The incidence was significantly higher in individual sports (P<0.01), low-physical demand sports (P<0.01), females (P<0.01), and at the elite level (P<0.01). Training load was not a significant predictor of NFOR/OT; however, competitive level and gender accounted for a small (4.7% and 1.7%, respectively) but significant explanatory variance of NFOR/OT (P<0.05). CONCLUSIONS Approximately one-third of young athletes have experienced NFOR/OT, making this an issue for parents and coaches to recognize. OT is not solely a training load-related problem with both physical and psychosocial factors identified as important contributors.

Overtraining and elite young athletes.

In comparison to adults, our knowledge of the overtraining syndrome in elite young athletes is lacking. The evidence indicates an incidence rate of ∼20-30%, with a relatively higher occurrence seen in individual sport athletes, females and those competing at the highest representative levels. The most commonly reported symptoms are similar to those observed in over trained adult athletes: increased perception of effort during exercise, frequent upper respiratory tract infections, muscle soreness, sleep disturbances, loss of appetite, mood disturbances, shortness of temper, decreased interest in training and competition, decreased self-confidence, inability to concentrate. The association between training load and overtraining is unclear, and underlines the importance of taking a holistic approach when trying to treat or prevent overtraining in the young athlete so that both training and non-training stressors are considered. Of particular relevance to the issue of overtraining in the elite young athlete are the development of a unidimensional identity, the lack of autonomy, disempowerment, perfectionist traits, conditional love, and unrealistic expectations. Overtraining syndrome is a complex phenomenon with unique and multiple antecedents for each individual; therefore, an open-minded and comprehensive perspective is needed to successfully treat/prevent this in the young athlete.

Reliability of heart rate variability measures at rest and during light exercise in children

Objectives: To investigate the reliability of heart rate variability (HRV) measures at rest and during light exercise in children. Methods: Short term (five minute) HRV was assessed in 12 children (11–12 years of age). HRV measures were collected at rest with the children supine, breathing at 12 breaths/min, and during exercise on a cycle ergometer while exercising at 25% of peak oxygen uptake. Both resting and exercise data were collected twice from each child. Results: Intraclass correlation coefficients were low to moderate for most measures with wide confidence intervals for each variable in both resting and exercise conditions. Random variation (typical error) within repeated measurements ranged from 31% to 187%. Conclusions: These preliminary findings suggest that HRV measures are unreliable at rest and during light exercise in children aged 11–12 years. Tighter control of extraneous influences is recommended.

Exercise performance and magnetic resonance imaging-determined thigh muscle volume in children

Abstract This study examined the relationships between thigh muscle volume (TMV) and aerobic and anaerobic performance in children. A total of 32 children, 16 boys and 16 girls, aged 9.9 (0.3) years completed a treadmill running test to exhaustion for the determination of peak oxygen uptake (peak V˙O2) and a Wingate Anaerobic Test (WAnT) for the determination of peak power (PP) and mean power (MP). The volume of the right thigh muscle was determined using magnetic resonance imaging. TMV was not significantly different in boys and girls [2.39 (0.29) l vs 2.18 (0.38) l, P > 0.05]. Peak V˙O2 and MP were significantly higher in boys than girls (P < 0.01) whether expressed in absolute, mass-related or allometrically scaled terms. Absolute PP was not significantly different in boys and girls but mass-related and allometrically scaled values were higher in boys (P < 0.01). TMV was correlated with absolute peak V˙O2, PP and MP in both sexes (r = 0.52–0.89, P < 0.01). In boys, mass-related PP was correlated with TMV (r =0.53, P < 0.01), and in girls mass-related peak V˙O2 was correlated with TMV (r = −0.61, P < 0.01). However, in neither sex were allometrically scaled peak V˙O2, PP or MP correlated with TMV (P > 0.05). There were no significant differences between boys and girls in terms of peak V˙O2, PP or MP when expressed in a ratio to TMV or allometrically scaled TMV. In conclusion, this study has demonstrated that, when body size is appropriately accounted for using allometric scaling, TMV is unrelated to indices of aerobic and anaerobic power in 10-year-old children. Furthermore, there appear to be no qualitative differences in the muscle function of boys and girls in respect of aerobic and anaerobic function.

Aerobic fitness and visceral adipose tissue in children

Aim: To determine the relationship between aerobic fitness (peak [image omitted] ) and the volume of visceral adipose tissue (VAT) in children. Methods: Participants were 30 males (13.7±0.5 y) and 22 females (13.5±0.5 y). Peak [image omitted] was determined using a continuous, incremental treadmill protocol to exhaustion. Abdominal VAT volume was measured by magnetic resonance imaging using multiple slices from vertebral levels L1–L5. Subcutaneous body fat measure was calculated as the sum of seven skinfolds (σ7SKF). Results: Females had significantly (p≤0.05) more VAT than males (1035±717.3 vs 678.6±361.5 cm3); however, male peak [image omitted] was higher (215±34 vs 182±20 ml/kg0.61/min). VAT was significantly (p≤0.05) negatively correlated with peak [image omitted] in both males (r= ‐ 0.43) and females (r= ‐ 0.45). Subcutaneous body fatness was significantly correlated with VAT in both males (r=0.74) and females (r=0.72), and was the single strongest determinant of VAT.

Prevalence of non-functional overreaching in elite male and female youth academy football players

ABSTRACT Purpose: The purpose of this study was to examine the prevalence of non-functional overreaching (NFOR) and overtraining (OT) in elite male and female youth football players. Methods: Two-hundred and forty-two youth football players (n = 138 boys and n = 104 girls) aged between 12 and 17 years completed a questionnaire to identify the occurrence of NFOR/OT and associated symptoms. Results: No players experienced OT. Significant sex differences for NFOR were found between girls 9% compared to boys 27% (P < 0.05). For players that experienced NFOR, 33% of girls and 60% of boys experienced multiple bouts. Compared to girls, boys completed higher volumes of football training (16.3 ± 4.5 versus 12.7 ± 5.7 h per week, P < 0.05), but training load was not a significant predictor of NFOR for either sex. In both sexes, NFOR was associated with tiredness, a lack of appetite, sore or heavy muscles, feeling in a bad mood, and feeling apathetic. Conclusion: Male and female elite youth football players engaged in high training volumes and experienced similar NFOR symptoms. However, there is a much higher prevalence of NFOR in boys and in those who have suffered previous bouts of NFOR.