Lyla,
Performing HIIT 5 days a week could be very grueling on the body. Yet, you ask the question, “Can one do it 5 days a weeks? That depends on certain factors.
One’s current level of fitness is important. A very overweight or clinically obese person would not be a candidate for HIIT. These individuals are primarily sugar burners. They’re body is still improving in its ability to absorb oxygen and utilize fat as the primary source of fuel. They’re conditioning level needs to improve in its oxygen uptake to metabolize the lactate HIIT creates.
For the inactive yet not very overweight or obese, I would recommend they build an aerobics base first. The primary recommendation I make for wanting to start incorporating HIIT is build up your body’s ability to absorb oxygen to process the high lactate levels HIIT will create when you perform it.
Someone with a good aerobics base can perform HIIT 5 days a week. However, I would alternate the MODE of exercise between impact and non-impact activities. You mentioned you had an elliptical machine. I would alternate that mode of exercise with say a treadmill or outside sprints.
Ground forces at such a high intensity can be very taxing on the body. Even one who has the perfect recovery diet and recovery tools like massage would have a difficult time recuperating.
In addition, overuse injuries (i.e. shin splints) could be a concern as well.
Having a strong strength and core base also is important. I’ve seen too many sit all day office workers go out to perform HIIT training and pull hamstrings, strain calf muscles, and rupture achilles. A whole body resistance training workout that works the major muscle groups in a balanced way, combined with a functional training routine that corrects muscle imbalances is important.
Of course this can be mitigated when you do it on non-impact machines like the elliptical. Believe it or not, I have found hills (such as treadmill incline) safer than flat ground sprinting as well. The angle of hills shifts the ground impact forces from directly impacting your lower back. I’ve yet to see one injury from anyone performing HIIT on hills. However, hills can be physically and mentally taxing and difficult to do 5 days a weeks.
Finally, because HIIT depletes your muscle glycogen stores, it’s imperative if one is doing HIIT 5 days a week their carb intake increase. Low-carb diets and HIIT do not get along. HIIT 5 days a week is equivalent to the training load of most athletes. Carb reloading is a mainstay of their intake in order to maintain the power and intensity of their workouts.
Departing advice is to listen to your body. We all know ourselves better than anyone else. Our bodies will let us know if we need to pull back or not. As an anecdote, I perform HIIT 5 days a week right now. I’m following all the advice I wrote above in this post. My body is doing fine, the results are awesome, yet I pay the price when I fail to refuel with adequate carbs.
I hope this helps.
GetFitn6
