Variation in the Correlation Between Heart Rate and Session Rating of Perceived Exertion-Based Estimations of Internal Training Load in Youth Soccer Players.

PURPOSE: When exposed to the same external load, players receive different internal loads, resulting in varied adaptations in fitness. In adult soccer, internal training load is measured using heart rate (HR) and session rating of perceived exertion (sRPE) scales, but these have been underutilized in youth soccer. This study investigated the in-season variation in correlation between HR and sRPE estimations of training load for adolescent soccer players. METHOD: Fifteen male professional adolescent players were monitored for 7 months. Within-participant correlations and Bland-Altman agreement plots for HR and sRPE were calculated for each month to analyze variation over the season and for individual players to analyze the validity of the scale. RESULTS: The monthly correlations ranged from r = .60 to r = .73 (P < .05) and the overall correlation was r = .64 (95% confidence interval, .60-.68; P < .001). Bland-Altman plots showed an agreement of methods. CONCLUSION: Results showed consistently large correlations for all months. sRPE is a consistent method of measure of internal training load for the entire season for youth soccer players. Validity analysis found no bias in sRPE measurements when compared with HR for all players in the study.

Monitoring Postmatch Fatigue During a Competitive Season in Elite Youth Soccer Players.

CONTEXT: Countermovement jump (CMJ) and perceived wellness measures are useful for monitoring fatigue. Fatigue indicators should simultaneously show sensitivity to previous load and demonstrate influence on subsequent physical output; however, these factors have not been examined. OBJECTIVE: To explore the efficacy of CMJ and wellness measures to both detect postmatch fatigue and predict subsequent physical match output in elite youth soccer players. DESIGN: Cross-sectional study. PATIENTS OR OTHER PARTICIPANTS: Sixteen soccer players (18 ± 1 years) from 36 English Football League Youth Alliance League fixtures. MAIN OUTCOME MEASURE(S): Physical match outputs (total distance, high-speed running, very high-speed running, and accelerations and decelerations [AD]) were recorded using a 10-Hz global positioning system and 200-Hz accelerometer device during competitive match play. The CMJ height and perceived wellness were assessed weekly and daily, respectively, as indirect indicators of fatigue. Four subunits of wellness (perceived soreness, energy, general stress, and sleep) were measured using customized psychometric questionnaires. RESULTS: Simple linear regression showed that match AD predicted energy (R2 = 0.08, P = .001), stress (R2 = 0.09, P < .001), and total wellness (R2 = 0.06, P = .002) at 2 days postmatch. The CMJ (R2 = 0.05, P = .002), stress (R2 = 0.08, P < .001), sleep (R2 = 0.03, P = .034), and total wellness (R2 = 0.05, P = .006) measures at 5 days prematch predicted AD during the subsequent match. CONCLUSIONS: The CMJ and wellness measures may be useful for detecting postmatch fatigue. Wellness scores, but not CMJ, at 5 days prematch influenced subsequent match output and therefore may be used to plan and periodize training for the upcoming microcycle.

The effect of elastic therapeutic taping on lumbar extensor isokinetic performance.

OBJECTIVES: To investigate the effects of elastic therapeutic tape when applied overlaying the lumbar extensors on different measures of muscle performance, compared to a placebo taping technique and a no-tape control. DESIGN: A cross-sectional experimental study. SETTING: A biomechanics laboratory. PARTICIPANTS: Twenty one participants received three taping conditions in a randomised order: elastic therapeutic tape, a placebo tape and a no-tape control. Peak torque, the time taken to reach peak torque and peak velocity were measured using an isokinetic dynamometer. MAIN OUTCOME MEASURES: Concentric lumbar extension peak torque at 60°/s, time taken to reach peak torque and peak velocity was measured using an isokinetic dynamometer. Friedman's test and post-hoc Wilcoxon signed-rank test were used to determine the statistical differences between the three taping conditions. Level of signicance was set at 0.05.fi. RESULTS: A statistically significant improvement in peak lumbar extensor torque was observed when comparing elastic therapeutic tape with the no-tape control (p < 0.05). However, there was no significant differences in time taken to reach peak torque and peak velocity (p > 0.05). CONCLUSIONS: Results demonstrate that the application of elastic therapeutic tape overlaying the primary lumbar extensors significantly improves the maximal lumbar extension peak torque in healthy, asymptomatic adults.