Comparison of Three Eccentric Overload Training Strategies on Power Output and Interlimb Asymmetry in Youth Soccer Players

Background: The present study compared the effects of performing the lateral squat exercise in three different formats from eccentric overload training on concentric/eccentric peak/mean power and inter-limb asymmetries in young soccer players. Methods: Forty-five young male (U-17) soccer players were distributed into three groups. Two groups performed the same training volume with both legs, beginning with the weaker leg (SVW, n = 15) or with the stronger leg (SVS, n = 15). The third group executed double volume with the weaker leg and also commenced with such leg (DVW, n = 15) in the lateral squat during a 10-week period. Pre- and post-intervention metrics included concentric and eccentric peak/mean power during the lateral squat test and their corresponding asymmetries. Results: All groups improved all power variables. Concentric mean and peak power asymmetry were substantially reduced in the SVW (ES: 0.89), DVW (ES: 0.43), and in SVW (ES: 1.60). Eccentric mean and peak power asymmetry were also substantially decreased in SVW (ES: 0.81) and in DVW (ES: 0.68). Between-group analyses showed substantially better performance in concentric and eccentric variables with stronger and weaker legs in SVW and DVW groups compared with SVS. Conclusions: Those groups which started with the weaker leg showed greater both power enhancements and reductions on inter-limb asymmetries.

Different forms of swimmers’ final weeks pre-competition preparation

The pre-competition training phase is a period that precedes the main competition. Combined training phases of overload training (OT) and taper (TP) create the most popular pattern of final form preparation among the swimmers despite the methodology difficulties faced by coaches. In the IPC, the duration and training load were strictly set. The main purpose of training in the IPC is to cause a substantial supercompensation effect by the high volume and capacity of the training. However, high volume and intensity fluctuations typical of the IPC may cause performance regression due to overtraining and exhaustion. The main aim of the taper phase (TP) is to provide recovery and develop peak racing capability for a particular event. This process relies on gradual reduction of training overload (mainly volume) in order to achieve the peak racing ability, after the planned, already achieved high level of swimming performance and efficiency. The duration of the TP and the form of load reduction are crucial factors affecting improvements in the swimmer’s competition times. The TP strategy was identified as the safest and the most beneficial one. This paper aims at providing characterization of training procedures used in IPC and TP, together with a presentation of the physiological mechanism exploited here and a possible performance improvement.

Muscle fiber typology is associated with the incidence of overreaching in response to overload training

Variability in the performance responses following an overload training period and subsequent taper was associated with the variation in the muscle fiber typology of the gastrocnemius. Runners with an estimated higher proportion of type I fibers (i.e., lower carnosine z-score) were able to maintain performance in response to an overload training period and subsequently achieve a superior performance supercompensation. These findings show that muscle fiber typology contributes to the variability in performance responses following training.

Using Infrared Thermal Imaging to Study the Response of Athletes to Overload Training

Objective: To study the changes of body surface temperature of Taekwondo athletes during overload training, and provide new ideas and means for athletes to evaluate their body response after overload training. Methods: The infrared thermography technique was used to monitor the body surface temperature of the chest and abdomen of the Taekwondo athletes, and the changes of body surface temperature were observed. The experiment used Beckman automatic biochemical analyzer to determine creatine kinase (CK) index. The experiment used the RPE scale to test the self-fatigue sensation. On the training day, the training starts at 9:00 am every day and the training is completed in 2 hours. The training starts at 14:00 in the afternoon and the training is completed in 2 hours. The morning training requires a minimum heart rate of 130 beats/min, and keeps it for more than 30 minutes. The training end time is 11:00; afternoon training requires a minimum heart rate of 170 beats/min, and maintained for more than 30 minutes, the training end time is 16:00. Results: The athletes’ sports injury parts increased significantly after exercise, which can indirectly reflect the athlete’s physical fatigue reaction state after overload training. Body surface temperature has a good consistency with creatine kinase (CK), heart rate, and body function response, indicating that body surface temperature values can replace creatine kinase (CK), heart rate, and self-physiological response, indicating that infrared thermography can be accurate. The physiological response status after overload training was assessed. Conclusion: The thermal imaging camera can accurately identify and analyze the injury and physiological response status of athletes. Infrared thermography studies show that the body surface temperature of athletes has a certain correlation with (CK); the body surface temperature and physiological fatigue response of athletes have certain Correlation law; the body surface temperature of the athlete has a correlation with the heart rate; the body surface temperature of the athlete’s sports injury site after the sports injury is significantly increased, which indirectly reflects the physical fatigue response of the athlete after overload training.

The Effects of Different Types of Eccentric Overload Training on Strength, Speed, Power and Change of Direction in Female Basketball Players

The aim of this study was to investigate the effect of two types of eccentric (ECC) overload training on strength, speed, power and change of direction in female basketball players. Twenty amateur basketball players (mean ± SD: age: 23.67 ± 6.05 years; height: 1.73 ± 0.05 m; body mass: 80.28 ± 17.67 kg) participated in a randomized trial. The players performed either flywheel inertial training (FIT) (n = 11) or tempo ECC training (TET) (n = 9) for 4 weeks, performing two sessions weekly. Performance characteristics, one repetition back squat (1RM), counter-movement jump (CMJ), squat jump (SJ), 10-metre sprint (10 m), change of direction (COD) and sit and reach flexibility (S&R) were tested pre and post intervention. Post-hoc testing revealed significant improvements in the FIT group for 1RM (p ≤ 0.001; ES = 0.59), 10 m (p = 0.003; ES = −0.54) and CMJ (p ≤ 0.001; ES = 1.04), while significant improvements were revealed in the TET group for 1RM (p = 0.007; ES = 0.71) and S&R (p ≤ 0.001; ES = 0.58). In conclusion, both FIT and TET groups demonstrated a positive training stimulus for increasing muscular strength. FIT may produce superior adaptions in CMJ and 10-m sprint, while TET may produce superior adaptions in S&R. Neither group achieved increases in either SJ or COD.

Effects of Different In-Season Strength Training Methods on Strength Gains and Water Polo Performance

Purpose: This study aimed to compare the effects of 5 different 18-week in-season strength training programs on strength gains and specific water polo performance. Methods: A total of 56 young male water polo players were randomly assigned to the following 5 training groups: dry-land strength training, in-water-specific strength training, combined (dry-land and in-water) strength training, ballistic training, and eccentric-overload training. Physical performance was assessed before (Pre) and after (Post) the training period using the following battery of tests: in-water boost and countermovement jump, muscle strength in bench-press and full-squat, throwing speed (ThS), in-water agility, and 20-m maximal sprint swim. Results: Significant group × time interactions were observed for countermovement jump and in-water boost. Eccentric-overload training showed significantly higher gains in ThS and bench-press and full-squat strength than the rest of the training groups. In addition, all training groups (except in-water-specific strength training) induced significant improvements (P ≤ .05) in countermovement jump, in-water boost, and bench-press and full-squat strength. All training groups significantly increased (P ≤ .001) ThS. Moreover, all training groups improved (P ≤ .05) in-water agility (except dry-land strength training) and swimming sprint performance (except in-water-specific strength training and ballistic training). Conclusion: The findings indicate that the 18-week in-season strength training programs induced improvements in strength and specific water polo skills. The eccentric-overload training resulted in greater improvements in muscle strength (in both upper and lower body) and ThS than the other training methods examined in the study.

A Comparison of 3 Different Unilateral Strength Training Strategies to Enhance Jumping Performance and Decrease Interlimb Asymmetries in Soccer Players

Purpose:To compare the effects of performing different unilateral strength training interventions on unilateral and bilateral jumping performance and their related asymmetries in young soccer players.Methods:Forty-five young (U-17) male soccer players were randomly assigned to 3 eccentric overload training programs. The first group executed the same volume with both legs starting with the weaker leg (SVW, n = 15); the second group carried out double volume with the weaker leg and also starting with the weaker leg (DVW, n = 15); and the third group performed the same volume with both legs starting with the stronger leg (SVS, n = 15). Jumping-performance assessment included a single-leg horizontal jump test, a triple single-leg horizontal jump test, a bilateral countermovement jump (CMJ) test, and a unilateral CMJ test. Asymmetries were also analyzed in the unilateral jumping tests.Results:CMJ was improved (effect size [ES]: 0.27–0.48) and CMJ asymmetry was possibly reduced (ES: 0.08–0.24) in all groups. Substantial improvements were found in triple hop (ES: 0.52–0.71) in SVW and DVW, and triple-hop asymmetry was substantially decreased (ES: 0.88) in DVW. Between-groups analysis showed a substantially better performance in triple hop and horizontal hop with right leg in SVW and DVW compared with SVS.Conclusions:Unilateral strength training programs were shown to substantially improve bilateral jumping performance, while unilateral jumping was substantially enhanced in the groups that started the training session with the weaker leg. Finally, between-limbs asymmetries in the triple hop were mainly reduced through performing double volume with the weaker leg.