If you don’t have a lot of time in your day to fit exercise in, you are not alone. This is probably the most common excuse I hear and I simply do not accept it. You don’t have to spend hours at the gym to get the results you want. Interval training basically refers to performing exercises in short increments while increasing and decreasing the intensity. I personally prefer to do short bursts of cardio and short bursts of strength training with minimal rest in between. If you are a beginner or plan to do many rounds, I would use a timer and stick with 30 second intervals. You can progress to 45 seconds or 1 minute. You can rest for about 10 seconds in between or go from one to the other with no rest. If you have a heart rate monitor you can also rest until your heart rate has come down a bit.
If you are a beginner you may want to set up your intervals like this:
As you improve, you should start by shortening the rest period in between the cardio and strength exercises. Then you can lengthen the amount of time you perform the exercises. OR you can pick up the pace or the cardio and add more weight to the strength.
I would do the same cardio and strength exercises 3 or 4 times before changing to another set. So maybe do 3 rounds of jacks and lunges then do 3 sets of stair runs and push-ups.
The beauty of interval training is that studies show you will see similar results as aerobic training in less time. You can perform intervals with minimal or no equipment. You can perform them anywhere. You can use intervals with just cardio on the treadmill or while you run/walk outside or while lifting weights. If you have only 10 or 15 minutes you will feel like you have worked out for an hour and burn more calories than if you had just performed 10 or 15 minutes of exercise at a steady pace.
*Keep in mind that interval training can be tough on your body and so I recommend a day of rest in between doing interval training or at least doing some other form of exercise in between.