Test-retest reliability of knee extensors endurance test with elastic resistance

Background

Reliable clinical tests capable of measuring resistance are important tools for rehabilitation. One alternative that has recently increased in popularity is the use of elastic tubes, which stand out for being easy to handle, low cost, practical, and feasible.

Objective

Analyze the test-retest reliability of the knee extensors muscle fatigue resistance test (FRT) with elastic tubes.

Methods

A total of 116 healthy young males, aged between 18 and 30 years old, participated in the study. Participants performed three pre-test stages: orientation, load presentation, and familiarization with equipment, lasting two weeks. Subsequently, they performed the FRT on two occasions (test and retest), with an interval of seven days. The reliability analyzes were performed using the intraclass correlation coefficient (ICC) with 95% confidence interval and typical measurement error (TME), also expressed as coefficient of variation (CV%).

Results

The findings regarding the reliability of the test demonstrated satisfactory values (time: ICC = 0.66; 95%CI [0.50; 0.76]; CV(%) = 9.34; repetition: ICC = 0.61; 95%CI [0.46; 0.73], CV(%) = 13.66; rhythm: ICC = 0.52; 95%CI [0.35; 0.67], CV(%) = 10.29.

Conclusion

From the findings presented, it is concluded that the proposed clinical test with elastic tubes demonstrates evidence of acceptable values.

Effect of low-level laser therapy (LLLT) and light-emitting diodes (LEDT) applied during combined training on performance and post-exercise recovery: protocol for a randomized placebo-controlled trial

BACKGROUND

Previous studies have shown positive results of phototherapy for improving performance and accelerating recovery; however, the effects of phototherapy during training and after a primary adaptation remain unclear. The aim of this randomized controlled trial is to analyze the effects of phototherapy and combined training on clinical, functional, and psychological outcomes and on vascular endothelial growth factor.

METHODS

This randomized placebo-controlled trial by stratified sample will involve 45 healthy male participants. In phase 1, the participants will undergo six weeks of combined training (sprints and squats). In phase 2, participants will be allocated through stratified randomization (based on adaptation capacity) into three groups: active phototherapy group (AG), placebo group (PG), and non-treatment control group (CG). A new six-week training program will then start and the participants will receive the recovery strategy between sprints and squats. The primary outcome will be maximal isometric contraction. The secondary outcomes include strength and power testing, maximal incremental test, squat jump, sprint test, muscle soreness, pain threshold, perceptions of exertion and recovery, psychological questionnaire, and vascular endothelial growth factor.

CONCLUSIONS

This will be the first trial to include phototherapy during training. We believe that this strategy will combine the ergogenic and prophylactic effects in the same session. Furthermore, an application protocol performed after primary adaptation may reflect the real effect of the technique.

Can Water Temperature and Immersion Time Influence the Effect of Cold Water Immersion on Muscle Soreness? A Systematic Review and Meta-Analysis

Background

Cold water immersion (CWI) is a technique commonly used in post-exercise recovery. However, the procedures involved in the technique may vary, particularly in terms of water temperature and immersion time, and the most effective approach remains unclear.

Objectives

The objective of this systematic review was to determine the efficacy of CWI in muscle soreness management compared with passive recovery. We also aimed to identify which water temperature and immersion time provides the best results.

Methods

The MEDLINE, EMBASE, SPORTDiscus, PEDro [Physiotherapy Evidence Database], and CENTRAL (Cochrane Central Register of Controlled Trials) databases were searched up to January 2015. Only randomized controlled trials that compared CWI to passive recovery were included in this review. Data were pooled in a meta-analysis and described as weighted mean differences (MDs) with 95 % confidence intervals (CIs).

Results

Nine studies were included for review and meta-analysis. The results of the meta-analysis revealed that CWI has a more positive effect than passive recovery in terms of immediate (MD = 0.290, 95 % CI 0.037, 0.543; p = 0.025) and delayed effects (MD = 0.315, 95 % CI 0.048, 0.581; p = 0.021). Water temperature of between 10 and 15 °C demonstrated the best results for immediate (MD = 0.273, 95 % CI 0.107, 0.440; p = 0.001) and delayed effects (MD = 0.317, 95 % CI 0.102, 0.532; p = 0.004). In terms of immersion time, immersion of between 10 and 15 min had the best results for immediate (MD = 0.227, 95 % 0.139, 0.314; p < 0.001) and delayed effects (MD = 0.317, 95 % 0.102, 0.532, p = 0.004).

Conclusions

The available evidence suggests that CWI can be slightly better than passive recovery in the management of muscle soreness. The results also demonstrated the presence of a dose–response relationship, indicating that CWI with a water temperature of between 11 and 15 °C and an immersion time of 11–15 min can provide the best results.

Electronic supplementary material

The online version of this article (doi:10.1007/s40279-015-0431-7) contains supplementary material, which is available to authorized users.

Effects of cold water immersion and active recovery on post-exercise heart rate variability

The aim of the present study was to investigate the potential benefits of cold water immersion (CWI) and active recovery (AR) on blood lactate concentration ([Lac]) and heart rate variability (HRV) indices following high-intensity exercise. 20 male subjects were recruited. On the first visit, an incremental test was performed to determine maximal oxygen consumption and the associated speed (MAS). The remaining 3 visits for the performance of constant velocity exhaustive tests at MAS and different recovery methods (6 min) were separated by 7-day intervals [randomized: CWI, AR or passive recovery (PR)]. The CWI and AR lowered [Lac] (p<0.05) at 11, 13 and 15 min after exercise cessation in comparison to PR. There was a 'time' and 'recovery mode' interaction for 2 HRV indices: standard deviation of normal R-R intervals (SDNN) (partial eta squared=0.114) and natural log of low-frequency power density (lnLF) (partial eta squared=0.090). CWI presented significantly higher SDNN compared to PR at 15 min of recovery (p<0.05). In addition, greater SDNN values were found in CWI vs. AR during the application of recovery interventions, and at 30 and 75 min post-exercise (p<0.05 for all differences). The lnLF during the recovery interventions and at 75 min post-exercise was greater using CWI compared with AR (p<0.05). For square root of the mean of the sum of the squares of differences between adjacent R-R intervals (RMSSD) and natural log of high-frequency power density (lnHF), a moderate effect size was found between CWI and PR during the recovery interventions and at 15 min post-exercise. Our findings show that AR and CWI offer benefits regarding the removal of [Lac] following high-intensity exercise. While limited, CWI results in some improvement in post-exercise cardiac autonomic regulation compared to AR and PR. Further, AR is not recommended if the aim is to accelerate the parasympathetic reactivation.