Patients often ask me what the best exercise is and my answer is “well, that depends on what you want me to do.” Most people realize that exercise is good for them, but they may not be clear on what kind of improvements they need.

Exercise produces a variety of benefits, including stronger muscles, a healthier heart, and increased flexibility. It is also useful in treating specific problems such as high blood pressure, depression, and diabetes.

To build a stronger, healthier heart, or to burn fat, use circuit training or aerobic exercise like walking, jogging, or bicycling. To build muscle in general, use some form of resistance training, such as weight training or bodyweight calisthenics, such as push-ups or pull-ups. To increase flexibility, perhaps a stretching class at a dance or yoga school.

But what if you don’t have time for two or three different types of exercise and are looking for an all-around exercise, something that will give you the most overall benefit for the time you can invest? So my answer is simple, WALK.

In my opinion, walking is the best single exercise overall. It won’t increase your strength as much as weight training, and you won’t become as flexible as doing yoga, but if you’re only going to do one form of exercise, then for its overall benefits, this is the one to go for.

What’s good about walking? First of all, most of us can walk already, you don’t need to spend time learning how before you can start reaping the rewards. It is cheap; all you need is appropriate footwear, or if the terrain and weather permit, it is even more beneficial to walk barefoot.

Walking causes very few injuries, you can do it from wherever you are, and it’s relatively easy to incorporate walking into your daily routine. Examples of how include parking a little further from work or the post office, or getting off the bus a stop or two early.

Brisk walking is an excellent low-impact aerobic exercise, so it will help strengthen your heart and burn excess fat. Walking also strengthens the larger muscles, those in the legs and hips. The weight-bearing nature of walking, especially if you’re going up hills, also puts a strain on your bones, which reduces the risk of osteoporosis.

The rhythmic movement of walking is a good mobility exercise for the spine, particularly the lower back that causes problems for so many people. Increased breathing helps keep the upper back and ribcage free while expelling waste gases from the lungs.

The rhythmic movement of the large muscles of the hip and diaphragm combine to produce a massage of the abdominal organs, which improves bowel function.

Walking can be modified to accommodate a variety of fitness goals. As you get fitter you can walk more and you can walk a little faster. Varying your route can greatly alter your exercise demands—walking to the end of the street and back could turn into a hike in the mountains. The hills place higher demands that lead to greater gains in both strength and aerobic fitness. Walking on uneven, natural ground can be used to increase balance and give you a great core stability workout.

You can take a solitary walk, giving yourself time to think, or walking can be an opportunity to socialize. Whether alone or with others, walking takes you out into the world, which can be therapeutic in itself. Many of us live hectic lives, cut off from nature, so taking a walk in the fresh air can give you the opportunity to gain a healthier outlook on life.