Hypoxic repeated sprint interval training improves cardiorespiratory fitness in sedentary young women

Exercise under hypoxia on glucose tolerance in type 2 diabetes mellitus risk individuals: A systematic review and meta-analysis

Objectives

To analyze the impact of exercise under hypoxic exposure versus normoxic exposure on blood glucose level, insulin level, and insulin sensitivity in people at risk of Type 2 diabetes mellitus (T2DM).

Materials and Methods

We systematically performed electronic searching on PubMed, Web of Science, ProQuest, and Scopus. Primary studies that met the inclusion criteria were analyzed using Revman 5.4.1.

Results

Nine randomized controlled trials were included in this meta-analysis. We found that physical exercise under hypoxic exposure had no significant effect on improving blood glucose levels, insulin levels, and insulin sensitivity in the elderly and sedentary people compared to normoxic condition. However, physical exercise during hypoxic exposure had a significant effect on lowering blood glucose levels in overweight/obese individuals (pooled Standardized Mean Difference = 0.29; 95% confidence interval = 0.01-0.57; P = 0.04).

Conclusions

Exercising under hypoxic exposure can be an alternative strategy for reducing blood glucose levels in overweight/obese people. Nevertheless, in other populations at risk of T2DM, exercising in hypoxic conditions gives similar results to normoxic conditions.

The Impact of Intermittent Hypoxic Training on Aerobic Capacity and Biometric-Structural Indicators among Obese Women-A Pilot Study

BACKGROUND

Obesity, a common lifestyle-related condition, is correlated with factors like inadequate physical activity. Its connection to diverse health issues presents a significant challenge to healthcare. This pilot study investigated the effects of hypoxic training on aerobic capacity and biometric-structural indicators in obese women. The secondary objective was to determine the feasibility, effectiveness, and safety of the planned research procedures and their potential for larger-scale implementation.

MATERIAL AND METHODS

Forty-one non-trained women with first-degree obesity were randomly assigned to even normobaric hypoxic training (H + E), normoxic training (E), passive exposure to hypoxia (H), and a control group (C). Training sessions were conducted three times a week for four weeks (12 training sessions). Body composition parameters were assessed, metabolic thresholds were determined, and maximal oxygen consumption (VO2max) was measured before and after interventions.

RESULTS

The results demonstrated that training in hypoxic conditions significantly affected somatic parameters, with the H + E group achieving the best outcomes in terms of weight reduction and improvements in body composition indicators (p < 0.001). Normoxic training also induced a positive impact on body weight and body composition, although the results were less significant compared to the H + E group (p < 0.001). Additionally, training in hypoxic conditions significantly improved the aerobic capacity among the participants (p < 0.001). The H + E group achieved the best results in enhancing respiratory endurance and oxygen consumption (p < 0.001).

CONCLUSIONS

The results of this pilot study suggest, that hypoxic training can be effective for weight reduction and improving the aerobic capacity in obese women. Despite study limitations, these findings indicate that hypoxic training could be an innovative approach to address obesity and related conditions. Caution is advised in interpreting the results, considering both the strengths and limitations of the pilot study. Before proceeding to a larger-scale study, the main study should be expanded, including aspects such as dietary control, monitoring physical activity, and biochemical blood analysis.

Comparative efficacy of various hypoxic training paradigms on maximal oxygen consumption: A systematic review and network meta-analysis

Background

Enhancement in maximal oxygen consumption (VO2max) induced by hypoxic training is important for both athletes and non-athletes. However, the lack of comparison of multiple paradigms and the exploration of related modulating factors leads to the inability to recommend the optimal regimen in different situations. This study aimed to investigate the efficacy of seven common hypoxic training paradigms on VO2max and associated moderators.

Methods

Electronic (i.e., five databases) and manual searches were performed, and 42 studies involving 1246 healthy adults were included. Pairwise meta-analyses were conducted to compare different hypoxic training paradigms and hypoxic training and control conditions. The Bayesian network meta-analysis model was applied to calculate the standardised mean differences (SMDs) of pre-post VO2max alteration among hypoxic training paradigms in overall, athlete, and non-athlete populations, while meta-regression analyses were employed to explore the relationships between covariates and SMDs.

Results

All seven hypoxic training paradigms were effective to varying degrees, with SMDs ranging from 1.45 to 7.10. Intermittent hypoxia interval training (IHIT) had the highest probability of being the most efficient hypoxic training paradigm in the overall population and athlete subgroup (42%, 44%), whereas intermittent hypoxic training (IHT) was the most promising hypoxic training paradigm among non-athletes (66%). Meta-regression analysis revealed that saturation hours (coefficient, 0.004; P = 0.038; 95% CI [0.0002, 0.0085]) accounted for variations of VO2max improvement induced by IHT.

Conclusion

Efficient hypoxic training paradigms for VO2max gains differed between athletes and non-athletes, with IHIT ranking best for athletes and IHT for non-athletes. The practicability of saturation hours is confirmed with respect to dose-response issues in the future hypoxic training and associated scientific research.

Registration

This study was registered in the PROSPERO international prospective register of systematic reviews (CRD42022333548).

The Emerging Role of Hypoxic Training for the Equine Athlete

This paper provides a comprehensive discussion on the physiological impacts of hypoxic training, its benefits to endurance performance, and a rationale for utilizing it to improve performance in the equine athlete. All exercise-induced training adaptations are governed by genetics. Exercise prescriptions can be tailored to elicit the desired physiological adaptations. Although the application of hypoxic stimuli on its own is not ideal to promote favorable molecular responses, exercise training under hypoxic conditions provides an optimal environment for maximizing physiological adaptations to enhance endurance performance. The combination of exercise training and hypoxia increases the activity of the hypoxia-inducible factor (HIF) pathway compared to training under normoxic conditions. Hypoxia-inducible factor-1 alpha (HIF-1α) is known as a master regulator of the expression of genes since over 100 genes are responsive to HIF-1α. For instance, HIF-1-inducible genes include those critical to erythropoiesis, angiogenesis, glucose metabolism, mitochondrial biogenesis, and glucose transport, all of which are intergral in physiological adaptations for endurance performance. Further, hypoxic training could conceivably have a role in equine rehabilitation when high-impact training is contraindicated but a quality training stimulus is desired. This is achievable through purpose-built equine motorized treadmills inside commercial hypoxic chambers.

EFFECTS OF PROGRESSIVE LOAD TRAINING ON SPRINTERS’ CARDIORESPIRATORY ENDURANCE

ABSTRACT Introduction: The most evident change during exercise is the increase in oxygen demand, and prolonged high-intensity exercises may impact this even more on this demand. Physical training with progressive loads is a method that aims to reach the training goals by adjusting factors such as initial load, stage load, and a load of the athletes and can be a monitor of the aerobic and anaerobic exercise on the athlete with potential benefits for the high demand of oxygenation. Objective: Study the changes in heart rate and indexes of cardiorespiratory endurance of sprinters under training with progressive loads. Methods: By random sampling, the study subjects were 15 male sprinters and 15 non-sportsmen as research volunteers. The study subjects performed a protocol with progressive load training on a platform. All subjects underwent the Italian Kosmai cardiopulmonary function test before and after training. Results: The subjects who did not practice the sport showed VO2 max values at an exercise intensity of 13 km/h. The VO2 max maximum for sprinters was 15 km/h. Individuals who were not sprinters generally showed lower VT levels than sprinters (P <0.05). Average non-speeder individuals demonstrated higher MET scores than sprinters. Conclusion: Cardiopulmonary endurance and energy metabolism levels are strongly related to long-term participation in physical activity and exercise intensity. Incremental load training improved cardiorespiratory fitness in sprinters. The results may provide a specific theoretical basis for the daily training of sprinters in the future. Level of evidence II; Therapeutic studies - investigation of treatment outcomes.

Effects of Sports Functional Food on Physical Function of Athletes under Ultrasound Observation

In order to improve the physical function of athletes under hypoxic training, the authors propose to observe the effect of functional food with active ingredients of polypeptide polyamines in deer antler on the physical function of athletes under ultrasound observation. According to the characteristics of physiological changes during hypoxic training, functional foods containing the active ingredients of polypeptide polyamines in deer antler were selected and given to athletes under simulated hypoxic training, observe the changes of red blood cells (RBC), hemoglobin (Hb), hematocrit (Hct), blood lactic acid, free radical metabolism and immune function of athletes, and musculoskeletal under ultrasound observation, discuss how to improve the physical function and athletic ability of athletes under hypoxic training. Experimental results show that athletes after 6 weeks of hypoxic training, red blood cells and hemoglobin were significantly increased, there was a significant difference compared to the control group (P < 0.05 or P < 0.01). After 6 weeks of hypoxic training, hemoglobin increased by 10.1%, a 5.6 percentage point increase compared to the control group. Conclusion. The antler peptides used by the authors can enhance the effect of hypoxic training.