Goal- Develop Aerobic Capacity
Method:
Measure your best 4 minute interval. Choose running, biking, swimming, boxing etc.
Go as far as you can in 4 minutes have a 2 minute rest!
Your goal is now to repeat this at about 90%. The first one is the measure and the following three you need to maintain. Hence they are called 4 minute repeats.
According to Dr Kevin Norton from uni sa. Intervals between 3-7 minutes for 3-5 rounds are the best way to grow your aerobic fitness. You can change up the time also for instance 10 on and 10 off for 4 minutes!