Over the past decade, aerobic fitness adaptations and health benefits following sprint interval training (SIT) have received much attention. However, the most commonly used SIT protocol, involving 4–6 repeated ‘all-out’ 30-s cycle sprints, is very demanding and not as time efficient as often suggested. |
Recent studies demonstrate that both the number of sprint repetitions and the sprint duration of SIT protocols can be reduced (to a point) without attenuating the associated health benefits. |
Based on the evidence that we present in this article, we contend that the focus of SIT research should be moved towards establishing acceptable and effective protocols that involve minimal sprint durations and repetitions. |
1 Background
2 What is the Evidence-Base for the Design of the Classic Sprint Interval Training (SIT) Protocol?
3 How Effective is the Classic SIT Protocol?
4 Do Proposed Mechanisms Support the Use of the Classic SIT Protocol?
5 Evidence to Support the Efficacy of Fewer and/or Shorter Sprints
Study | Subjects | Training parameters | Outcome | ||||
---|---|---|---|---|---|---|---|
Duration (weeks) | Frequency (sessions/week) | Sprint duration (s) | Sprint repetitions | Total training time per session (min) | |||
Shorter sprints | |||||||
Hazell et al. [53] | 48 M (ra) | 2 | 3 | 10 vs. 30 | 4–6 | 11 vs. 21 vs. 23 | No significant difference between increases in \(\dot{V}\)O2max with 30-s sprints (9.3%), 10-s sprints with 4-min recovery (9.2%), or 10-s sprints with 2-min recovery (3.8%) |
Zelt et al. [41] | 36 M (ra) | 4 | 3 | 15 vs. 30 | 4–6 | 35 | No significant difference between the increases in \(\dot{V}\)O2max with 30-s sprints (5.3%) or 15-s sprints (7.4%) |
Fewer sprints | |||||||
Allemeier et al. [23] | 17 M (ra) | 6 | 2.5 | 30 | 3 | 41.5 | 13.5% increase in \(\dot{V}\)O2max |
Ijichi et al. [77] | 20 M (ra) | 4 | 2.5 vs. 5 | 30 | 3 vs. 6 | 21.5 vs. 103 | No significant difference between the increase in \(\dot{V}\)O2max with 3 sprints 5 times/week (13.9%) or 6 sprints 2.5 times/week (8.4%) |
Shorter and fewer sprints | |||||||
Songsorn et al. [75] | 30 M/F (sed/ra) | 4 | 3 | 20 | 1 | 0.3 | No significant increase in \(\dot{V}\)O2max |
Songsorn et al. [76] | 10 M/F (sed/ra) | 4 | 3 | 20 | 1 | 4.3 | No significant increase in \(\dot{V}\)O2max |
Metcalfe et al. [67] | 29 M/F (sed) | 6 | 3 | 20 | 2 | 10 | 12.7% increase in \(\dot{V}\)O2max; 28% increase in Si in men |
Metcalfe et al. [74] | 35 M/F (sed) | 6 | 3 | 20 | 2 | 10 | 9.6% increase in \(\dot{V}\)O2max; trend toward 10% decrease in OGTT insulin AUC |
Ruffino et al. [87] | 16 M (T2D) | 8 | 3 | 20 | 2 | 10 | 7.3% increase in \(\dot{V}\)O2max; 4% decrease in MAP, no significant change in Si |
Gillen et al. [78] | 14 M/F (o/o sed) | 6 | 3 | 20 | 3 | 10 | 12% increase in \(\dot{V}\)O2max; 7% decrease in MAP, 8% decrease in CGM AUC |
Gillen et al. [57] | 25 M (sed) | 12 | 3 | 20 | 3 | 10 | 19% increase in \(\dot{V}\)O2max; 53% increase in Si, changes similar to MICT |