Interval Training
Interval training is another super efficient method of improving your endurance and cardio-respiratory response. The idea is that for short periods you break out of your “comfort” exercise zone by e.g .increasing your intensity, or increasing your speed, or number of repetitions, or amount of rest time.

By doing this you promote an adaption response whereby you can improve your aerobic and anaerobic capacity. Basically, you will train aerobically “with oxygen” for any exercise lasting more than a few minutes whilst anaerobic training is associated with short burst exercise such a sprinting or lifting. This form of training does not need oxygen to promote energy release.
By utilizing interval training you are gradually increasing the threshold at which fatigue takes over.This is particularly true for anaerobic exercise where the dreaded lactic acid build up can stop you exercising altogether.

Interval training can be incorporated into almost any form of exercise and when combined with a circuit based format can produce terrific fitness gains.