Its time to up the intensity! Interval training is exercise involving high intensity bursts of exercise, alternated with low or moderate intensities or rest periods. Many trainers/strength and conditioning specialists use this form of exercise, as it is very effective in increasing aerobic capacity (endurance) as well as burning lots of calories.

Clients tend to enjoy this type of training as well as it can constantly be adapted therefore you never get bored during training. Also, due to the high intensity nature of the exercise you really feel like you have had a good workout afterwards.

An example of an interval session is as follows:

Warm up (5-10 minutes moderate exercise)
3 minutes of moderate intensity running
2 minutes of walking
= 5 mins
Repeat 5 times
Cool down and stretch

Or

Warm up (5-10 minutes moderate exercise)
1 minute low intensity cardio; 30 seconds high intensity cardio
1 minute low intensity cardio; 45 seconds high intensity cardio
1 minute low intensity cardio; 60 seconds high intensity cardio
1 minute low intensity cardio; 45 seconds high intensity cardio
1 minute low intensity cardio; 30 seconds high intensity cardio
Rest 3-5 minutes
Repeat 3 times
Cool down and stretch

Rules

Always have a good warm up before sessions.

Start slowly and progress over time.

If you suffer from a chronic condition or haven’t been exercising in a while always consult your doctor or exercise professional before starting with an interval training program.

Allow your heart rate to drop to 100-110 beats per minute during rest phases before starting the next set.

If you are wanting to progress the session, either increase the intensity or the duration. Not both.
Other progressions can be made in increasing duration of the high intensity work, decreasing rest time, increasing the number of reps. But be sure that you are ready for these progressions and that you do not attempt this too soon in your program.