Date Published: 2010

Studies have shown that low-intensity resistance training (LIRT) with vascular occlusion – known as kaatsu training – induced muscle hypertrophy (increase in muscle size). Kaatsu training creates ‘localised’ hypoxia by reducing the blood flow to the chosen muscle being trained. This study hypothesised that muscle hypertrophy can be induced more efficiently by placing the entire body in an hypoxic environment.

14 male university students were randomly assigned to hypoxia (H) and normoxia (sea level) (N). Each training session was completed at 70 per cent of 1 rep max (1RM), and was comprised of four sets of 10 reps of elbow extension and flexion.

Participants exercised twice weekly for 6 weeks, after which muscle hypertrophy was assessed by magnetic resonance imaging and muscle strength by 1RM.

Results found that muscle hypertrophy was significantly greater for the hypoxic group, and muscle strength was significantly increased early (by week 3) in the hypoxic group compared to the normoxic group.

These findings suggest resistance exercise in a hypoxic environment delivers promising training results, encouraging circuit-style and body weight classes in addition to more traditional cardiovascular style sessions.