The Effects of Sprint Interval Training on Aerobic Fitness: A Systematic Review

Background: Greater aerobic fitness is associated with improved cardiovascular health. Traditionally high volume (long duration and low intensity) endurance training (ET) has been used to increase aerobic fitness. Sprint interval training (SIT) is a low volume and high intensity form of interval training. Energy for SIT is produced via both the aerobic and anaerobic metabolic pathways. SIT is therefore a potentially efficient and effective means to improve aerobic fitness. Objectives: Systematically review the effects of SIT on aerobic endurance performance in untrained individuals. Methods: The following databases were searched up to August 2008: Pubmed, the Cochrane Library, ScienceDirect, and SportsDiscuss. The reference lists of relevant reviews and identified papers were also searched. Included articles were limited to English language, controlled studies, investigating SIT in healthy untrained or recreationally active participants (VO2max < 55ml/kg/min)(1) with an outcome measure of endurance performance (as a measure of aerobic fitness). Studies fulfilling the selection criteria were assessed for methodological quality and relevant outcome data extracted. Results: A qualitative evaluation of the available evidence demonstrated a consistent association between sprint interval training and improved aerobic performance. SIT produced an improvement of ~ 4% (95%CI -0.2 to 8.7), ~8 to 10% (0.4 to 16), and ~15% (0.8 to 29) after 1, 2 and 6 weeks respectively. These improvements were of the same magnitude as the improvements noted for ET but the training volume required was approximately 90% less. Conclusions: Short duration SIT is an effective and efficient form of improving aerobic fitness in untrained individuals.