Previous studies have shown that an interval training (IT) based on short term (30 second long) maximal intensity bouts of exercise (5 all-out cycle-ergometer 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.