Sprint Interval Training (SIT)

(C) Erika Fulk

Do you incorporate high intensity efforts into your training plan? As a runner or cyclist, endurance training is KING….but neglecting the high intensity will only hinder your growth and progression within the sport. More important, for those with limited time for training, studies show that getting the higher intensities into the workouts tends to help “supplement” the lack of training duration.

In an article published in the October edition of Sports Medicine, researchers out of Atlanta conducted a literature review (meta-analysis) of studies conducted with high intensity, short duration (30s) efforts and their effect on aerobic capacity. They found that the effects on endurance trained athletes were not convincing, but in those with lower conditioning levels (or less training volume) responded favorably.  See the Abstract:


Sprint interval training (SIT) involving repeated 30-s “all out” efforts have resulted in significantly improved skeletal muscle oxidative capacity, maximal oxygen uptake, and endurance performance. The positive impact of SIT on cardiorespiratory fitness has far-reaching health implications.


The objective of this study was to perform a systematic review of the literature and meta-analysis to determine the effects of SIT on aerobic capacity.


A search of the literature was conducted using the key words ‘sprint interval training’, ‘high intensity intermittent training/exercise’, ‘aerobic capacity’, and ‘maximal oxygen uptake’. Seventeen effects were analyzed from 16 randomized controlled trials of 318 participants. The mean ± standard deviation number of participants was 18.7 ± 5.1. Participant age was 23.5 ± 4.3 years.


The effect size calculated for all studies indicates that supramaximal-intensity SIT has a small-to-moderate effect (Cohen’s d = 0.32, 95 % CI 0.10-0.55; z = 2.79, P < 0.01) on aerobic capacity with an aggregate improvement of ~3.6 mL·kg(-1)·min(-1) (~8 % increase). The effect is moderate to large in comparison with no-exercise control groups (Cohen’s d = 0.69, 95 % CI 0.46-0.93; z = 5.84, P < 0.01) and not different when compared with endurance training control groups (Cohen’s d = 0.04, 95 % CI -0.17 to 0.24; z = 0.36, P = 0.72).


SIT improves aerobic capacity in healthy, young people. Relative to continuous endurance training of moderate intensity, SIT presents an equally effective alternative with a reduced volume of activity. This evaluation of effects and analysis of moderating variables consolidates the findings of small-sample studies and contributes to the practical application of SIT to improve cardiorespiratory fitness and health.

Granted, there is a “time and a place” for these efforts, but the bottom line: rev your engine to anaerobic levels to improve your aerobic capacity!


 Nicholas H. GistMichael V. FedewaRod K. DishmanKirk J. Cureton Sprint Interval Training Effects on Aerobic Capacity: A Systematic Review and Meta-Analysis. Sports Medicine October 2013