An Update to a Comprehensive Assessment of the Methods and Effectiveness of Resistance Training in Normobaric Hypoxia for the Development of Strength and Muscular Hypertrophy

Abstract

Background. Training muscle capacities in hypoxic conditions increases some manifestations, such as hypertrophy and muscle strength, due to a change in the muscle phenotype as a result of the activation of hypoxia-inducible factors (HIF). Despite the proven benefits of resistance training in hypoxic conditions that allow conjecture regarding the effectiveness in facilitating muscular capacities in different populations, there is still controversy regarding the difference between resistance training in hypoxia and normoxia. The objective of this review was to compile the present evidence and update the methods and effectiveness of resistance training in simulated hypoxia for the development of strength and muscle hypertrophy. Methodology. A systematic search for an integrative review was carried out based on the preferred reporting guidelines for systematic reviews and meta-analysis (PRISMA) in 4 stages: identification, data selection, data collection and extraction, and quality evolution. Results. Four studies (92 participants) reported benefits in strength when training in hypoxia, three (101 participants) benefits in hypertrophy, and twelve (327 participants) benefits in strength and hypertrophy. Conclusion. Based on the findings of this systematic review, it is concluded that there are positive effects on muscle size and ability to generate force after a hypoxic training programme. However, some studies did not show a statistically greater benefit than for the normoxia groups, but several methodologies have been identified that promote the benefits of hypoxia.