Influence of Competition Day on Cognitive Control and HRV in Young Male Gymnasts

Young Artistic Gymnasts Drink Ad Libitum Only Half of Their Fluid Lost during Training, but More Fluid Intake Does Not Influence Performance

To examine the effect of the fluid balance on and performance in young artistic gymnasts during training under ad libitum and prescribed fluid intake conditions, eleven males (12.3 ± 2.6 years, mean ± SD) performed two 3 h identical training sessions. Participants ingested, in a random order, water equivalent to either 50% (LV) or 150% (HV) of their fluid loss. After the 3 h training, the gymnasts performed program routines on three apparatuses. The pre-exercise urine specific gravity (USG) was similar between conditions (LV: 1.018 ± 0.007 vs. HV: 1.015 ± 0.007; p = 0.09), while the post-exercise USG was lower in the HV condition (LV: 1.017 ± 0.006 vs. HV: 1.002 ± 0.003; p < 0.001). Fluid loss corresponding to percentage of body mass was higher in the LV condition (1.2 ± 0.5%) compared to the HV condition (0.4 ± 0.8%) (p = 0.02); however, the sums of the score performances were not different (LV: 26.17 ± 2.04 vs. HV: 26.05 ± 2.00; p = 0.57). Ingesting fluid equivalent to about 50% of the fluid lost, which was the amount that was drunk ad libitum during training, maintained short-term hydration levels and avoided excessive dehydration in artistic preadolescent and adolescent gymnasts. A higher amount of fluid, equivalent to about 1.5 times the fluid loss, did not provide an additional performance benefit.

Relationships between Heart Rate Variability, Sleep Duration, Cortisol and Physical Training in Young Athletes

The aims of the current study were to examine the relationships between heart rate variability (HRV), salivary cortisol, sleep duration and training in young athletes. Eight athletes (16 ± 1 years) were monitored for 7 weeks during training and competition seasons. Subjects were training for endurance-based winter sports (cross-country skiing and biathlon). Training was divided into two zones (K1, easy training and K2, hard training). Heart rate and blood lactate during submaximal running tests (SRT), as well as cortisol, sleep duration and nocturnal HRV (RMSSD), were determined every other week. HRV and cortisol levels were correlated throughout the 7-week period (r = -0.552, P = 0.01), with the strongest correlation during week 7 (r = -0.879, P = 0.01). The relative changes in K1 and HRV showed a positive correlation from weeks 1-3 (r = 0.863, P = 0.006) and a negative correlation during weeks 3-5 (r = -0.760, P = 0.029). The relative change in sleep during weeks 1-3 were negatively correlated with cortisol (r = -0.762, P = 0.028) and K2 (r = -0.762, P = 0.028). In conclusion, HRV appears to reflect the recovery of young athletes during high loads of physical and/or physiological stress. Cortisol levels also reflected this recovery, but significant change required a longer period than HRV, suggesting that cortisol may be less sensitive to stress than HRV. Moreover, our results indicated that during the competition season, recovery for young endurance athletes increased in duration and additional sleep may be beneficial.

Sleep quality monitoring in individual sports athletes: parameters and definitions by systematic review

In the present review, we identify which instruments and parameters are used for sleep quality monitoring in individual sport athletes and which definitions were used for sleep quality parameters in this literature field. Systematic searches for articles reporting the qualitative markers related to sleep in team sport athletes were conducted in PubMed, Scopus and Web of Science online databases. The systematic review followed the Preferred Reporting Items for Systematic Reviews. The initial search returned 3316 articles. After the removal of duplicate articles, eligibility assessment, 75 studies were included in this systematic review. Our main findings were that the most widely used measurement instruments were Actigraphy (25%), Rating Likert Scales (16%) and Sleep Diary (13%). On sleep quality parameters (Sleep duration = 14%; Wake after sleep onset = 14%; Sleep Quality = 12%; Sleep Effciency = 11% and Sleep Latency = 9%), the main point is that there are different definitions for the same parameters in many cases reported in the literature. We conclude that the most widely used instruments for monitoring sleep quality were Actigraphy, Likert scales and Sleep diary. Moreover, the definitions of sleep parameters are inconsistent in the literature, hindering the understanding of the sleep-sport performance relationship.

Heart rate variability as a possible predictor of sport performance in junior rhythmic gymnastics

BACKGROUND: Heart rate variability may reveal sensitive information about the athletes’ physiological adaptation when exercising for sport performance. OBJECTIVE: The aim of this study was to demonstrate whether heart rate variability (HRV) measurements were able to predict sport results and determine which type of measurements, at rest or during routines, were relevant in anticipating the performance. METHOD: Ten female gymnasts, aged 11–14 years old, and 16 age-matched non-active adolescents participated in this study. HRV was measured at rest for 10 minutes and throughout the training routines one week prior to competition. Correlations and multivariate analysis determined the parameters predicting performance. Significance was set at p⩽ 0.05. Results: At rest, the gymnasts displayed higher HRV values than controls. At rest, sympathetic parameters correlated with sport results whereas no correlation was observed during routines. The magnitude of the predictive factors highlighted the importance of Ln SD2 (coefficient =-117, 95CI -130 to -106), Ln RMSSD (coefficient =-24.5, 95CI -29.2 to -19.8), Ln pNN50 (coefficient =-10.7, 95CI -11.5 to -9.9), and Ln Total power (coefficient =-2.5, 95CI -13.4 to -11.5). CONCLUSIONS: HRV at rest may predict results in competition, being a complementary tool for coaches.

Sleep duration, body composition, dietary profile and eating behaviours among children and adolescents: a comparison between Portuguese acrobatic gymnasts

Sleep, body composition and dietary intake are crucial for athletes' health and performance but have never been investigated in acrobatic gymnasts. Thus, this study aimed to evaluate sleep, body composition, dietary intake and eating behaviours of acrobatic gymnasts. Using a cross-sectional study, 82 Portuguese acrobatic gymnasts (12.8 ± 3.1 years, 61 females and 21 males) were evaluated during the competitive period to collect training data, sleep duration, body composition, dietary intake and eating behaviours before, during and after practices. Most of the gymnasts (91.5%) slept less than 8 h/night. Female adolescents slept significantly less on weekdays than female children (P = 0.024). Female adolescents' mean body mass was below the normal and 60.0% showed menstrual irregularities; 4.9% of females bases were overweight and 2.4% obese. Male adolescents slept significantly less on weekdays than male children (P = 0.001); significant differences were shown for fat-free mass (P = 0.014); however, 3.7% were overweight. All daily energy and macronutrient intakes were significantly different according to age and gender, with exception for fibre and energy intake in females (P = 0.057 and P = 0.052, respectively), and for protein in males (P = 0.068). Female and male adolescents demonstrated significant lower energy availability (32.8 ± 9.4 kcal/kg FFM/day and 45.1 ± 14.7 kcal/kg FFM/day) than children (45.8 ± 8.7 kcal/kg FFM/day and 53.8 ± 9.1 kcal/kg FFM/day), respectively. Significant low intakes of important vitamins and minerals were reported. Most of the participants did not eat or drink during or immediately after training sessions.

CONCLUSION

Acrobatic gymnasts revealed low BF, short sleep duration and macro- and micronutrients inadequate intakes. The Female Athlete Triad was demonstrated by female adolescent gymnasts. What is Known: • Adequate dietary intake is an important resource for athletes' short and long-term health and performance. • There are no published studies in acrobatic gymnasts' sleep, body composition or dietary intake. What is New: • This study provides the first data on significant differences in energy intake and availability between acrobatic gymnasts; overweight and obesity were present in females. • Macro and micronutrients were inappropriate. Female Athlete Triad was observed in female adolescent acrobatic gymnasts.