Time of VO(2)max plateau and post-exercise oxygen consumption during incremental exercise testing in young mountain bike and road cyclists

Relationship between body composition and anaerobic power with inter-limb difference dependence in Czech elite ice hockey players

BACKGROUND

Ice hockey includes symmetrical as well as asymmetrical movements. As such, possible difference in mass and strength, as well as performance variables, may be observed between limbs.

METHODS

We examined the relation between body composition and lower extremity anaerobic power in Czech elite ice hockey players with the inter-limb difference dependence. In total, 168 ice hockey players (age = 20.81, Q1 = 18.24, Q3 = 28.75) underwent body composition measurement and Wingate Anaerobic Test (WAnT). The dominant (D) and non-dominant (ND) leg was established. A Wilcoxon Signed Rank was used. The difference between the dominant and non-dominant lower extremities was evaluated using the dimensionless analysis and by setting the value for the dominant leg at 100%.

RESULTS

The difference in muscle mass (MM), fat mass (FM), and WAnT outcome variables (MP, RAP, MP5sP) between the right and left leg was greater than the difference between D and ND leg. Less total body fat mass (TBFM) and more total body muscle mass (TBMM) and lower extremities muscle mass (LEMM) were associated with higher WAnT outcome values. The dimensionless analysis showed a statistically significant correlation between almost all variables.

CONCLUSIONS

More TBMF and LEMM and less TBFM was better for WAnT. The difference between the right and left leg was greater than the difference between D and ND leg. If there is a difference between MM and FM of lower limbs than there could be difference between the power of lower limbs as well.

A Subject-Tailored Variability-Based Platform for Overcoming the Plateau Effect in Sports Training: A Narrative Review

The plateau effect in training is a significant obstacle for professional athletes and average subjects. It evolves from both the muscle-nerve-axis-associated performance and various cardiorespiratory parameters. Compensatory adaptation mechanisms contribute to a lack of continuous improvement with most exercise regimens. Attempts to overcome this plateau in exercise have been only partially successful, and it remains a significant unmet need in both healthy subjects and those suffering from chronic neuromuscular, cardiopulmonary, and metabolic diseases. Variability patterns characterize many biological processes, from cellular to organ levels. The present review discusses the significant obstacles in overcoming the plateau in training and establishes a platform to implement subject-tailored variability patterns to prevent and overcome this plateau in muscle and cardiorespiratory performance.

Real Assessment of Maximum Oxygen Uptake as a Verification After an Incremental Test Versus Without a Test

The study was conducted to compare peak oxygen uptake (VO_2peak) measured with the incremental graded test (GXT) (VO_2peak) and two tests to verify maximum oxygen uptake, performed 15 min after the incremental test (VO_2peak1) and on a separate day (VO_2peak2). The aim was to determine which of the verification tests is more accurate and, more generally, to validate the VO_2max obtained in the incremental graded test on cycle ergometer. The study involved 23 participants with varying levels of physical activity. Analysis of variance showed no statistically significant differences for repeated measurements (F = 2.28, p = 0.118, η² = 0.12). Bland–Altman analysis revealed a small bias of the VO_2peak1 results compared to the VO_2peak (0.4 ml⋅min^–1⋅kg^–1) and VO_2peak2 results compared to the VO_2peak (−0.76 ml⋅min^–1⋅kg^–1). In isolated cases, it was observed that VO_2peak1 and VO_2peak2 differed by more than 5% from VO_2peak. Considering the above, it can be stated that among young people, there are no statistically significant differences between the values of VO_2peak measured in the following tests. However, in individual cases, the need to verify the maximum oxygen uptake is stated, but performing a second verification test on a separate day has no additional benefit.

SIMULATION OF THE RELATIONSHIP BETWEEN EXERCISE AND CARDIOPULMONARY FUNCTION AT HIGH ALTITUDE

ABSTRACT Introduction: Due to various uncertain and unexpected factors in life such as diseases, natural disasters, traffic accidents, and congenital disabilities, the number and proportion of lower limb amputations are still rising for many reasons, so the research on lower limb prostheses is particularly important. Objective: This work aimed to study the relationship between altitude exercise and cardiopulmonary function. Methods: A model of abnormal changes in cardiopulmonary function was established, and then 40 plateau exercisers were selected, all of whom arrived in Tibet in March 2017. The relationship between pulmonary circulation volume and internal pressure in the chest was observed and compared. The relationship between cardiopulmonary sensory reflex and exercise (high altitude) breathing and heart rate was analyzed. A comparison of the cardiopulmonary function of subjects of different genders was implemented. Moreover, the influence of different altitudes on the subjects’ cardiopulmonary function and the subjects’ cardiopulmonary function changes before departure and during the first, second, and third week after departure were observed and compared. Results: I. As the pressure in the thoracic cavity increased, the subjects’ pulmonary circulation blood volume gradually decreased, and the decrease was most obvious in the stage of thoracic pressure −50 to 0. II. As the cardiorespiratory reflex coefficient increased, the subjects’ breathing and heart rate compensatory acceleration appeared. III. Tracking and monitoring of the subjects’ cardiopulmonary indicators revealed that with the increase in altitude, the subjects’ average arterial pressure, respiratory frequency, and heart rate all showed an upward trend, while the blood oxygen saturation value showed a downward trend. IV. No matter how high the altitude was, the average arterial pressure, respiratory rate, and heart rate monitored of the subjects under exercise were significantly superior to the indicator values under resting state. In contrast, the blood oxygen saturation value showed the opposite trend. V. The subjects’ average arterial pressure, respiration, and heart rate in the first week were higher than other periods, but the blood oxygen saturation was relatively lower. In the second and third weeks, the changes in cardiopulmonary function were relatively smooth (all P<0.05). VI. The changes in the index of the cardiopulmonary function of subjects of different genders were small (p>0.05). Conclusion: Through modeling, the results of the plateau environment on the cardiopulmonary function of the body were made clearer, and these research data provided theoretical references for the training of the sports field in the plateau area. Level of evidence II; Therapeutic studies - investigation of treatment results.

Effect of high-intensity exercise on cardiorespiratory fitness in stroke survivors: A systematic review and meta-analysis

BACKGROUND

Knowledge of the optimal protocol and safety of particularly high-intensity exercise applied to individuals with stroke is lacking.

OBJECTIVE

This systematic review and meta-analysis aimed to investigate the effect of high-intensity exercise on cardiorespiratory fitness in stroke survivors.

METHODS

We performed a systematic electronic search for articles in MedLine via PubMed, EMBASE, Web of Science, Cochrane Central Register of Controlled Trials, CINAHL, and SPORTSDiscus up to April 1, 2019. Peak oxygen consumption (VO₂peak), 6-min walk test (6MWT), fastest 10-m walk test (10MWT), and adverse events were assessed. The standardized mean difference (SMD), weighted mean difference (WMD), and odds ratios (ORs) were used to compute the effect size, and subgroup analysis was conducted to test the consistency of results as well as sensitivity analysis to assess the robustness of the results. The quality of evidence was assessed with the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) system.

RESULTS

We included 17 studies (PEDro score≥4) in the meta-analysis. Post-intervention, high-intensity exercise had a significant effect on peak oxygen uptake (VO₂peak; SMD=0.56, P<0.01, I²=8%; WMD=2.53mL/kg/min; high quality of evidence) and 6MWT (SMD=0.26, P<0.01, I²=40%; WMD=17.08m; moderate quality of evidence) but not fastest 10MWT (SMD=0.33, P=0.27, I²=77%; WMD=0.05m/s; low quality of evidence). Subgroup analysis showed better effects of higher-intensity treadmill training (≥70% heart rate reserve/VO₂peak) for a longer duration (≥12 weeks) on VO₂peak and 6MWT in sub-acute or chronic stroke survivors. The high-intensity exercise and control groups did not differ in adverse events including falls [odds ratio (OR) 1.40, P=0.35, I²=11%; low quality of evidence], pain (OR 3.34, P=0.09, I²=0%; moderate quality of evidence), or skin injuries (OR 1.08, P=0.90, I²=0%; low quality of evidence).

CONCLUSIONS

Our meta-analysis suggests that high-intensity exercise is beneficial for cardiorespiratory fitness in stroke survivors and might be safe as a novel intervention in cardiopulmonary rehabilitation after stroke.

Assessment of the physical fitness of road cyclists in the step and ramp protocols of the incremental test

BACKGROUND

The incremental test in laboratory conditions is a method commonly used to evaluate the maximal oxygen uptake and peak power output, which are the good predictors of cycling performance. But the best-designed protocol remains unknown. Therefore, the aim of this study was to examine the physiological and biochemical responses in the incremental ramp on cycle ergometer and to compare with the commonly used step in young road cyclists.

METHODS

Fifty-seven road cyclists took part in the experiment. The tests included two visits to the laboratory during which the anthropometric measurements, incremental test on a cycle ergometer, and examination of acid-base balance and blood lactate concentration were made. A randomly selected half of the subjects made, as the first one, the STEP (50W·3min-1) Test and the RAMP Test (~0,27W·sec-1) a week later. The remaining cyclists made tests in the reverse order.

RESULTS

The peak power output obtained in the RAMP was significantly higher than obtained in the STEP by 18.13W (P<0.05). The maximal oxygen uptake was higher by 1.5 (mL∙kg-1∙min-1) during the RAMP (P<0.05). The postexercise blood lactate concentration was significantly higher by 0.94 mmol∙L-1(P<0.05) in STEP.

CONCLUSIONS

We recommend the use of RAMP Test with linearly increasing workload to determine peak power output, maximal oxygen uptake and ventilatory threshold to precisely programming and control training of young road cyclists.