Effects on aerobic fitness of an upper limb high intensity interval training

Previous studies have shown that an interval training (IT) based on short term (30 second long) maximal intensity bouts of exercise (5 all-out cycloergometer exercises) improves aerobic fitness (Gibala et al., J Physiol 2006) due to an increased skeletal muscle carbohydrate metabolism (Burgomaster et al., J Appl Physiol 2006). We hypothesized that also an IT consisting of 5 bouts of exercise up to exhaustion carried out with an arm cranking ergometer (ACE) at an intensity ranging from 130 to 150% of peak of oxygen uptake (peak VO2) would be effective in improving upper body aerobic fitness. Eight healthy male subjects (age 39.4±10.42 years, mass 80±8.8 kg and height 1.8±0.07 m) were submitted to an ACE maximal incremental test to assess peak VO2 and to establish the intensity for IT (130% peak power). IT lasted 6 weeks (3 sessions per week). Each session consisted of 5 bouts of ACE exercise carried out up to exhaustion and interspaced by a recovery time necessary to start each bout every 5 minutes. A bout of exercise (mean power: 215±23.9 watt) lasted 75±7.5 s and 126±3.4 s at the start and at the end of training, respectively, eliciting a VO2 increase up to 90.2±6.72% of peak VO2. Peak VO2 increased after training from 36.8±7.25 to 40.4±4.87 ml kg-1 min-1 (p=0.001). A high intensity ACE IT, in which overload derives from both a greater mechanical work (from 74±10.9 to 137±23.3 kJ) and a shorter recovery time, improves significantly upper body aerobic fitness.