Effects of soccer training on health-related physical fitness measures in male adolescents

Purpose: The aims of this study were to(1) investigate the health-related physical fitness profile of untrained adolescent boys in comparison to adolescent soccer players,(2) determine the intensity and enjoyment of 6 v 6 and 4 v 4 small-sided games, and(3) evaluate the health-related effects of a short-period of soccer training in the untrained group.Methods: Forty-one adolescent boys(untrained, n = 24: age = 15.9 ± 0.6 years; trained, n = 17: age = 15.7 ± 0.7 years) were recruited. For Purpose 1,the players(n = 17) and the untrained(n = 24) boys were tested for speed, jumping power, postural balance, flexibility, and aerobic capacity. After baseline testing, Purposes 2 and 3 were addressed by randomly assigning the untrained boys to either a soccer-training group(small-sided games,2 sessions per week for 8 weeks) or to a control group, followed by identical retesting.Results: At baseline, physical fitness was higher(p < 0.001) in trained players than in untrained for aerobic fitness, sprinting, jumping power, and postural balance. Small-sided games using 6 v 6 or 4 v 4 elicited similar heart rate(HR)(mean: ~ 85% peak heart rate, HR_(peak)), rate of perceived exertion, and enjoyment responses. Over 8 weeks, the between-group analysis revealed that soccer training had a large beneficial effect on postural balance(45%) when compared with control group with unclear effects on other fitness parameters.Conclusion: Adolescent soccer players had markedly higher physical fitness compared with untrained adolescents. Small-sided soccer games practiced by untrained adolescents elicited high exercise intensity. While 8 weeks of twice-weekly soccer training sessions induced significant improvement in postural balance, the short duration of the study was not sufficient to result in between-group differences in sprint and jump performance or aerobic fitness.

Training session intensity affects plasma redox status in amateur rhythmic gymnasts

Purpose:The aim of this study was to examine systemic responses of oxidant/antioxidant status following 2 training sessions of different intensity in amateur rhythmic gymnasts.Methods:Before the experimental training,10 female gymnasts performed a gradually increased exercise test to assess maximal heart rate,maximal oxygen consumption,and anaerobic threshold.They executed 2 intermittent training sessions separated by 48 h of recovery(48 h-post R):the first was performed at low-moderate intensity(LMI)and the second at high intensity(HI).Blood samples were collected immediately preand post-training and 48 h-post R.Hydroperoxide level(OxL)and total antioxidant capacity(TAC)were photometrically measured.Results:OxL was significantly higher in post-training and 48 h-post R following HI than the same conditions after an LMI session(HI vs.LMI post-training:381.10±46.17(mean±SD)vs.344.18±27.94 Units Carratelli(U.CARR);48 h-post R:412.21±26.61 vs.373.80±36.08 U.CARR).There was no change in TAC between the 2 training sessions investigated.In LMI training,OxL significantly decreased in post-training and increased to reach the baseline at 48 h-post R,whereas TAC increased only at 48 h-post R.In HI training,OxL significantly increased to reach a high oxidative stress 48 h-post R,whereas TAC was lower in post-training than pre-training.Conclusion:The pattern of OxL and TAC levels implies different regulation mechanisms by HI and LMI training sessions.High oxidative stress induced by an HI protocol might be associated with both insufficient TAC and recovery time at 48 h necessary to restore redox balance.

The Influence of Biological Maturity on Dynamic Force-Time Variables and Vaulting Performance in Young Female Gymnasts

Purpose This cross-sectional study investigated dynamic force-time variables and vaulting performance in young female gymnasts of different maturity status.Methods 120 gymnasts aged 5-14 years were sub-divided into maturity groupings using percent of predicted adult height(%PAH)attained.Participants performed three jumping protocols,the squat jump(SJ),countermovement jump(CMJ)and drop jump(DJ),before completing straight jump vaults that were recorded using two-dimensional video.Results Jumping performance improved with biological maturity evidenced by the most mature gymnasts’producing sig-nificantly more absolute force(P<0.05;all d>0.78),impulse(P<0.05;all d>0.75)and power(P<0.05;all d>0.91)than the least mature group,resulting in the greater jump heights(P<0.05;all d>0.70).While,no significant differences were observed in relative peak force across multiple tests,measures of relative peak power did significantly increase with maturity.Based upon regression analyses,maturation was found to influence vertical take-off velocity during vaulting,explaining 41%of the variance in each jumping protocol.Across all tests,the DJ was found to have the highest predictive ability of vaulting vertical take-off velocity,explaining 55%of the total variance.Conclusion Biological maturation impacts jump height and underpinning mechanical variables in young female gymnasts.Vaulting vertical take-off velocity appears to be influenced by maturation and various dynamic force-time variables,par-ticularly those during DJ,which had the highest explained total variance.