I’ve written a few posts recently about how I’m incorporating more sprints and high intensity workouts into my routine.
Now a study published in the journal BMC Endocrine Disorders by James Timmons a Heriot-Watt University professor of exercise biology provides evidence that it’s also better for health reasons, and specifically because it increases insulin sensitivity.
Why does this matter?
It’s important because weight gain and type 2 diabetes are closely linked to insulin insensitivity.
The study used six sessions of sprint interval exercise on a stationary bike spread over 14 days, with 1 or 2 days of rest between each session. The individual workouts consisted of 4-6 repeated 30 second all out efforts with up to 4 minutes between efforts.
What was the effect of this low volume training? The study notes:
The low volume, high intensity training utilized in the current study significantly reduced both glucose AUC (-12%) and insulin AUC (-37%), with a sustained improved insulin action until at least day three after the last exercise session.
This was considerably better than the control group, and better than that achieved by usual low intensity aerobic sessions. Note also that the effects last at least three days after the end of the session. Professor Timmons calls the results ‘remarkable’.
All this on under 8 minutes of intense exercise per week.
If I was structuring an interval exercise session I would probably keep the work:rest ratio at 1:3 rather than the 1:8 ratio used in the study. This would also reduce the time taken for the overall session.
Sunday: Sprint intervals – 4 rounds of: 400m run, 2 min 30 sec rest; 4 rounds of: 200m run, 1 min rest.
Monday: 3 rounds of: sprint 100m, 20 squats, 20 pushups, 20 box jumps.
Wednesday: Using a barbell: 10 x overhead press, 10 x lunge, 10 x front squat, 10 x power clean, 10 x hang clean. Repeat complex with 8 and 6 reps.