The best preparation for hiking Mount Rinjani is to hike as much as you can up hills or mountains to imitate the ascent. Day walks are excellent practice. If you have a gym membership but no access to trails, you can train quite well on a stairmaster machine. Try to walk as much as you can, preferably on weekends when you have more time, if you don’t have access to trails or a gym.
If you have never hiked before, start with shorter time intervals, a slower speed, and no weight (in your daypack), then progressively raise all of the above as your fitness level rises. Keep in mind that you’ll be walking slowly and for extended periods of time on Mount Rinjani, and your daypack probably won’t hold more than 10 kg. Therefore, it is preferable to increase the time interval or distance and maintain a moderate pace during your training than to decrease the time interval or distance and raise the pace.Try to exercise three times per week for a minimum of an hour each time.
You’re probably ready for the real thing if you can walk on a Stairmaster for one to two hours at 30 steps per minute while carrying a 10-kilogram pack, or if you can complete day treks lasting four to six hours with modest elevation changes (around 1,000 feet or 305 meters).