Though physical fitness is an important part of any outdoor activity, you do not need to be an athletes or marathon runner to enjoy the trekking in the Himalaya. Most people of good fitness for their age can complete our trek. Most first-time trekkers are concerned that they won't keep up, but soon discover that a steady pace will have them in destination well before they would have expected but the fitter you are, the more you will enjoy it, and you will have enough energy for extra activities.
There are two basic components of preparation - aerobics and strength.
Aerobics conditioning is important primarily because you will trekking in thinner air, up to 40% less than at sea level. With good aerobic conditioning you will be able to better metabolize whatever oxygen is available to you.
You should plan on doing atleast one hour of aerobic 3 to 4 times per week for 1 month or more before the trek. Walking, jogging, cycling, hiking are some of the excellent forms of exercise, so long as you are strengthening leg muscles and building stamina. When following an exercise schedule it is important to use weekend for a LONG run/ walk which should ideally be at least 10 km’s long.
Strength Training is the most efficient exercise for trekking and adventure pursuits is exercise that develop the key muscle groups and aerobic fitness at a similar level. The main muscle group that will be used are in the quadriceps (thighs), glutes, hamstrings and calves and the oxygen demand by this muscle groups is high, requiring a good level of aerobic efficiency.