Acute physiological responses to eccentric cycling: a systematic review and meta-analysis

INTRODUCTION

Eccentric cycling (ECCCYC) has attracted considerable interest due to its potential applicability for exercise treatment/training of patients with poor exercise tolerance as well as healthy and trained individuals. Conversely, little is known about the acute physiological responses to this exercise modality, thus challenging its proper prescription. This study aimed to provide precise estimates of the acute physiological responses to ECCCYC in comparison to traditional concentric cycling (CONCYC).

EVIDENCE ACQUISITION

Searches were performed until November 2021 using the PubMed, Embase, and ScienceDirect databases. Studies that examined individuals' cardiorespiratory, metabolic, and perceptual responses to ECCCYC and CONCYC sessions were included. Bayesian multilevel meta-analysis models were used to estimate the population mean difference between acute physiological responses from ECCCYC and CONCYC bouts. Twenty-one studies were included in this review.

EVIDENCE SYNTHESIS

The meta-analyses showed that ECCCYC induced lower cardiorespiratory (i.e., V̇O2, V̇E, and HR), metabolic (i.e., [BLa]), and perceptual (i.e., RPE) responses than CONCYC performed at the same absolute power output, while greater cardiovascular strain (i.e., greater increases in HR, Q, MAP, [norepinephrine], and lower SV) was detected when compared to CONCYC performed at the same V̇O2.

CONCLUSIONS

The prescription of ECCCYC based on workloads used in the CONCYC sessions may be considered safe and, therefore, feasible for the rehabilitation of individuals with poor exercise tolerance. However, the prescription of ECCCYC based on the V̇O2 obtained during CONCYC sessions should be conducted with caution, especially in clinical settings, since there is a high probability of additional cardiovascular overload in this condition.

Association between internal training load and muscle injuries in Brazilian professional soccer players

The training load is associated with injury risk in a variety of sports. This study aimed to evaluate the association between the internal training load and injury risk in Brazilian professional soccer players. The data were collected from 32 soccer players across two full seasons (2017 and 2018). The rating of perceived exertion (RPE) for every training/match session was used as an internal load variable. The cumulative training load from 3 and 4 weeks (C3 and C4) and the acute:chronic workload ratio (ACWR) were calculated. A generalized estimating equation analysis was applied to examine associations of non-contact muscle injuries with C3, C4 and ACWR. A total of 33 injuries were recorded across the two full seasons. A significant association was found between cumulative training load for three (C3, p = 0.003) and four weeks (C4, p = 0.023) and the occurrence of injuries. Players in the "high load" group presented greater injury risk in relation to the "moderate load" group (C4: OR = 4.5; IC 95% 1.5-13.3; C3: OR = 3.7; IC 95% 1.7-8.1). There was no association between ACWR and injury occurrence. The athletes exposed to a high cumulative load in a period of 3 to 4 weeks presented higher injury risk in comparison to those who had moderate cumulative training loads. Besides that, there was no association between ACWR and injury occurrence.

The Impact of Pre-Exercise Carbohydrate Meal on the Effects of Yerba Mate Drink on Metabolism, Performance, and Antioxidant Status in Trained Male Cyclists

Introduction

The consumption of yerba mate (YM), a source of antioxidants, in a fasted state increases fatty acid oxidation (FAT_ox) during low–moderate-intensity exercise and improves performance in high-intensity exercise. However, the impact of a pre-exercise carbohydrate (CHO) meal on YM effects during exercise is unknown.

Objective

We investigated the effects of yerba mate drink (YMD) consumed in the fasted state (YMD-F) or after a CHO meal (YMD-CHO) on measurements of metabolism, performance, and blood oxidative stress markers in cycling exercise.

Methods

In a randomized, repeated-measures, crossover design, eight trained male cyclists ingested (i) YMD-CHO, (ii) YMD-F, or (iii) control-water and CHO meal (Control-CHO). The YMD (an infusion of 5 g of ultrarefined leaves in 250 mL of water) was taken for 7 days and 40 min before exercise. CHO meal (1 g/kg body mass) was consumed 60 min before exercise. The cycling protocol included a 40-min low-intensity (~ 53% V̇O_2peak) constant load test (CLT); a 20-min time trial (TT); and 4 × 10-s all-out sprints. Blood samples and respiratory gases were collected before, during, and/or after tests.

Results

During CLT, YMD-CHO increased FAT_ox ~ 13% vs. YMD-F (P = 0.041) and ~ 27% vs. Control-CHO (P < 0.001). During TT, YMD-CHO increased FAT_ox ~ 160% vs. YMD-F (P < 0.001) and ~ 150% vs. Control-CHO (P < 0.001). Power output during TT improved ~ 3% (P = 0.022) in YMD-CHO vs. Control-CHO and was strongly correlated with changes in serum total antioxidant capacity (r = −0.87) and oxidative stress index (r = 0.76) at post-exercise in YMD-CHO. Performance in sprints was not affected by YMD.

Conclusion

CHO intake did not negate the effect of YMD on FAT_ox or TT performance. Instead, a synergism between the two dietary strategies may be present.

Clinical Trial Registration NCT04642144. November 18, 2020. Retrospectively registered.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40798-022-00482-3.

Physiological and Perceptual Responses in Spinal Cord Injury Handcyclists During an Endurance Interval Training: The Role of Critical Speed

OBJECTIVE

This study sought to determine the physiological (oxygen uptake, heart rate, and blood lactate concentration) and perceptual (rating of perceived exertion) responses during an endurance interval training at the critical speed in elite handcyclists with spinal cord injury.

DESIGN

Eight handcyclists performed an incremental test, three tests to exhaustion at a constant speed to determine critical speed, and the endurance interval training. The endurance interval training consisted of 6 × 5 mins at the individualized critical speed, with passive recovery of 50 secs. All testing was performed using their own handcycles on an oversized motorized treadmill. Physiological and perceptual responses were assessed during the incremental and endurance interval training tests.

RESULTS

There was no significant difference in average oxygen uptake from the first to the sixth repetition. The mean ∆[La-]10_last between the 10th to the 30th minute of the exercise was -0.36 mmol·l-1, and no difference was detected from the first to the sixth repetition. The heart rate also remained stable during endurance interval training, whereas rating of perceived exertion increased significantly throughout the session.

CONCLUSIONS

Repetitions of 5 mins at the critical speed in elite handcyclists are associated with cardiorespiratory and lactate steady state, whereas the perceived exertion increased systematically.

Jiu-Jitsu-Specific Performance Test: Reliability Analysis and Construct Validity in Competitive Athletes

ABSTRACT

da Silva Junior, JN, Kons, RL, de Lucas, RD, and Detanico, D. Jiu-jitsu-specific performance test: Reliability analysis and construct validity in competitive athletes. J Strength Cond Res 36(1): 174-179, 2022-The aim of this study was twofold: to analyze the test-retest reliability and sensitivity of Jiu-Jitsu "anaerobic" performance test (JJAPT) variables, and to determine the construct validity of JJAPT by comparing groups of athletes with different levels and technical profiles. Sixty Brazilian Jiu-Jitsu (BJJ) athletes participated in this study. The reliability analysis was performed with all athletes and the construct validity was tested in the group comparisons-novice vs. advanced level and guard versus pass fighters. From the JJAPT, the number of repetitions, rate of perceived exertion (RPE) and average heart rate were assessed over the 5 sets. The test-retest reliability was assessed by absolute and relative analysis for each variable. The construct validity was tested by comparison means and the receiving operator characteristic (ROC) curve was used with the level of significance set at 5%. The main results demonstrated excellent test-retest reliability for all but the RPE in the first sets, with good sensitivity and agreement. The maximal number of repetitions in the JJAPT showed good construct validity, as it showed sensitivity to discriminate the performance between the advanced and novice BJJ athletes (p < 0.001, ROC curve area of 0.95). However, no significant difference was found between the technical profile groups (p > 0.05). We concluded that the JJAPT presents excellent performance reliability as a specific-sport test. In addition, the test presented evidence of construct validity, because it discriminated the performance between the advanced and novice BJJ athletes.

Intermittent versus Continuous Incremental Field Tests: Are Maximal Variables Interchangeable?

The aim of the present study was to compare physiological responses derived from an incremental progressive field test with a constant speed test i.e. intermittent versus continuous protocol. Two progressive maximum tests (Carminatti`s test (T-CAR) and the Vameval test (T-VAM)), characterized by increasing speed were used. T-CAR is an intermittent incremental test, performed as shuttle runs; while T-VAM is a continuous incremental test performed on an athletic track. Eighteen physically active, healthy young subjects (21.9 ± 2.0 years; 76.5 ± 8.6 kg, 1.78 ± 0.08 m, 11.2 ± 5.4% body fat), volunteered for this study. Subjects performed four different maximum test sessions conducted in the field: two incremental tests and two time to exhaustion tests (TTE) at peak test velocities (PV). No significant differences were found for PV (T-CAR = 15.6 ± 1.2; T-VAM = 15.5 ± 1.3 km·h(-1)) and maximal HR (T-CAR = 195 ± 11; T- VAM = 194 ± 14 bpm). During TTE, there were no significant differences for HR (TTET-CAR and TTET-VAM = 192 ± 12 bpm). However, there was a significant difference in TTE (p = 0.04) (TTET-CAR = 379 ± 84, TTET-VAM = 338 ± 58 s) with a low correlation (r = 0.41). The blood lactate concentration measured at the end of the TTE tests, showed no significant difference (TTET-CAR = 13.2 ± 2.4 vs. TTET-VAM = 12.9 ± 2.4 mmol·l(-1)). Based on the present findings, it is suggested that the maximal variables derived from T-CAR and T-VAM can be interchangeable in the design of training programs. Key pointsT-CAR is an intermittent shuttle run test that predicts the maximal aerobic speed with accuracy, hence, test results could be interchangeable with continuous straight-line tests.T-CAR provides valid field data for evaluating aerobic fitness.In comparison with T-VAM, T-CAR may be a more favourable way to prescribe intermittent training using a shuttle-running protocol.

Is the critical running speed related to the intermittent maximal lactate steady state?

The purpose of the present study was to compare the critical speed (CS) with the speed at the maximal lactate steady state (vMLSS) determined by a continuous and an intermittent model in trained runners. Eight male endurance runners (30.3 ± 10.6 years; 65.0 ± 8.5 kg; 1.73 ± 0.6 m; 11.3 ± 4.0% body fat) volunteered for this investigation and performed an incremental treadmill test, as well as 2-5 30-min constant speed tests to determine the MLSS continuous and MLSS intermittent (5 min of running, interspaced by 1 min of passive rest). The CS was determined by 2 maximal running efforts of 1500 and 3000 m performed on a 400 m running track. The CS was calculated as the slope of the linear regression of distance versus time. Statistical analysis revealed no significant difference between CS and MLSS determined by intermittent running (15.2 ± 1.0 km·h(-1) vs. 15.3 ± 0.7 km·h(-1), respectively), however, both were significantly higher than continuous MLSS (14.4 ± 0.6 km·h(-1)). There was also a significant correlation between CS and MLSS intermittent (r = 0.84, p = 0.008). On the basis of the present results, we conclude that for practical reasons (low cost, non-invasive) the CS is an interesting and alternative method to prescribe endurance interval training at maximal lactate steady state intensity, in preference to a continuous protocol.