1 Minute of Sprint Interval Training vs 45 Minutes Continuous Interval Training
Exercise, and specifically cardiovascular training is important for our health, we all know that.
What is less clear is what is the optimal way to exercise. What is the most efficient? What is the healthiest?
We know it helps prevent chronic diseases like diabetes, heart attacks and strokes, but how do we fit it into our busy schedule?
Sprint interval training is characterized by brief bursts of high intensity exercise followed by periods of rest in between. One common model is four-to-six 30 second all out cycles with 4 minutes between each set. Among the many potential advantages is that it is less time consuming.
Previous studies have suggested that sprint interval training is similar to regular moderate intensity continuous training in terms of cardiorespiratory fitness, skeletal muscle oxidative capacity and insulin sensitivity.
What is less clear is what is the optimal sprint interval training duration in terms of the intense component and the rest component.
The purpose of this study was to evaluate that.
They recruited sedentary men who performed weekly sessions of sprint interval training (9 individuals) or moderate-intensity continuous training (10 individuals) for 12 weeks.
Sprint interval training was 3x 20 second all out cycle sprints with 2 minutes of rest at low speed between sets.
Moderate intensity continuous training was 45 minutes of continuous cycling at 70% max heart rate
There were also 6 non-training controls.
Peak oxygen uptake increased by 19% in both groups.
Insulin sensitivity increased similarly in both groups. This was measured by IV glucose tolerance test before and 72 hours after training.
Skeletal muscle mitochondrial content also increased similarly in both groups as measured by citrate synthesis
Twelve weeks of sprint interval training was equivalent to moderate intensity continuous training for indices of cardiometabolic health.
This occurred despite consuming only roughly 20% of the same time.
What will be interesting is to see if this equates to equivalent weight loss or cardiovascular fitness and other measures of health.
Gillen, J. B., Martin, B. J., & Macinnis, M. J. (2016). Twelve Weeks of Sprint Interval Training Improves Indices of Cardiometabolic Health Similar to Traditional Endurance Training despite a Five-Fold Lower Exercise Volume and Time Commitment. Plos One, 11(4). doi:10.1371/journal.pone.0154075