If you have not exercised for a while or even if you have, high intensity interval training (HIIT) is definitely something to incorporate into your physical activity. This is regardless of whether your goal is to increase your lean muscle or prepare for an endurance event.
High intensity activity is all about working incredibly intensely in an oxygen-poor state for a short period of time with intervals to recover your breath i.e. to recover oxygen levels in your body. What this does is put your body under stress for a short period of time, which is hugely beneficial. This is because this stress encourages muscle cells to increase mitochondria which can really make a difference to your training as well as your level of heath.
Mitochondria are the power houses of your cells where fat is burned for energy. The more mitochondria you have, the more you can use your fat stores to produce energy and the better you feel.
Science has recently revealed that your mitochondria can benefit in other ways. If we have not exercised for a while and we start working aerobically e.g. with jogging there is a possibility we can produce too many free radicals with the oxygen we are taking in. This can even make more sedentary people ill when they begin to exercise.
However if we start with high intensity exercise and then move towards endurance endurance exercise we will have a large number of mitochondria. These mitochondria produce free radicals too but these ones activate anti-oxidant systems in our cells that can even make us live longer. In The In-Sync Diet we list foods that support mitochondrial function.