Heres how to choose.
The only catch: those 20-second bursts have to be really,reallyintense.
If you want themost effectiveinterval workout, look for one where the bursts of effort are 3-5 minutes long.
Be warned: its hard to keep up the needed intensity for 3-5 minutes.
Want to Try High-Intensity Interval Training?
Consider These Four Things| The Globe and Mail
Photo by theNorth Carolina National Guard.
