HIIT or high intensity interval training is an excellent way to train and not only effective but also proven extremely safe for people undergoing rehab in case of heart disease.

A 2012 study in the journal Circulation, by a Norwegian research team led by O. Rognmo, examined the risk of cardiovascular events during organized high-intensity interval exercise training and moderate-intensity training among 4846 patients with coronary heart disease in 3 Norwegian cardiac rehabilitation centers. The results of the study indicated that the risk of a cardiovascular event is low after both high-intensity exercise and moderate-intensity exercise in a cardiovascular rehabilitation setting. Considering the significant cardiovascular adaptations associated with high-intensity exercise, such exercise should be considered among patients with coronary heart disease.

But even then, there are certain precautions to be taken before you go for it:

• HIIT is not for absolute beginners. You must have a base of strength and endurance training before you move on to HIIT. According to ACSM, such people may have a higher risk of coronary heart disease to high-intensity exercise.
• Also, a sedentary lifestyle combined with medical issues like hypertension, diabetes, abnormal cholesterol levels and obesity with worsening lifestyle habits like cigarette smoking may pose a higher risk.

In fact, in our gym we use a lot of unconventional tools for workouts like ropes, chains, sandbags, tyres, slam balls, animal movements, etc. and I have seen in a lot of cases when a person is a beginner, or an overconfident brat, who has done everything except training, are not able to sustain 10 min of total training due to the high intensity involved in it.

So, go slow, but go progressive.