You need to get your heart rate up for complete health and fitness. Past advice had you exercise for at least 15-20 minutes at a steady pace to hit this goal. Intervals reverse this paradigm completely.
Intervals are efficient. You can keep time constant after achieving the minimum to improve your cardio. I suggest your interval workout take no longer than 5 minutes.
Please be sensible. Get used to exercise with easy activity such as walking. Although in theory you should have a self-regulation due to your out-of-shapeness, in practice this can harm you if you are in poor health due to the very high demands. Perform intervals only as a healthy, if less fit, individual.
Traditional intervals had longer rest periods versus work periods. To strike a balance between anaerobic (sprint) and aerobic (long) fitness, I suggest reversing these periods. Use a work length longer than the rest length.
Six to eight very hard 20 second intervals with 10 second rest periods may be one of the best possible training protocols. The fact is that the rate of increase in V02 max is one of the highest ever reported in exercise science.
– Izumi Tabata
Aim to perform more work in the same amount of time. You need to set intensities, a work period, a rest period, and the number of cycles. You need to make progress measurable.
Your intensities are determined by the distance you cover and the number of reps you achieve. You can also add resistance to your body or any implement you use such as a sled or hill for sprinting or vest for stairclimbing.
The work period is how long you cover a distance and perform reps until you stop to rest.
The rest period is a halt or very easy pace where you recover briefly before proceeding to the next work period.
The number of cycles is how many times you repeat both a work and rest period.
Let’s apply this to jumping.
It is simple, functional, and measurable. Jumps involve lots of muscle for movement. You can perform it anywhere and it works very well.
Pick a high spot on a wall or a ceiling to touch with your hand. Make the height challenging but doable. You can adjust this later if needed. Set a number of jumps to achieve per work period for your height. Try to achieve a 7-8 in terms of effort at a 1-10 scale. This first session will establish a standard. Let’s say you try to get 10 jumps every 20 seconds for a spot 18 inches above the max reach of your hand. You rest for 10 seconds afterward. In the future, you could also add weight via a weighted vest or backpack. You attempt to do this height and pace for 8 cycles or 4 minutes.
If you achieve this goal, bump up the demands for the next workout. Jump a higher distance, get more jumps, or add weight. Any of these options work but focus on getting your heart rate up. Too much resistance or height and not enough jumps will have muscle endurance or strength as the limiting factors instead.
If you find it becomes too difficult to achieve your goals in later cycles, finish doing your best. If you could achieve the intensity for most of the cycles then keep all the factors the same. If not, set an easier goal for yourself in some way.
If you know better, do better.
– Maya Angelou
You now have a brief yet brutal way to get your heart rate up. Combine this with a few good resistance training exercises and perhaps some stretching and light activity throughout the week. You now have a thorough and efficient program.
How many times a week for intervals? Pay attention to your body and take into account the other forms of exercise you do. The higher your performance relative to your first time, the less often you should do it. Some can perform it almost everyday and others do best just twice or even once a week. Try to progress in some very small way each workout.
You can now design an interval training workout, the most efficient way to elevate your heart rate and obtain cardiovascular fitness.