We see children playing, and they have no limit to what they are willing to do. They run and jump and climb. They fall and then they get up again. You might feel like telling them to slow down, but you never have to tell children to speed up.

But things change when you get older, at least for most people. Somehow many people get the idea that they are too old to exercise. You see it in many people soon after high school. They just aren’t active anymore. They think that their running and jumping days are behind them. It just isn’t true.

You can be active at any age. And you can use exercise, heavy exercise, to help you get the lean body that you want.

Now, before you strap on the gym shoes and start sprinting you have to know a few things. One is that if you have let yourself get too out of shape you will need a gradual approach to vigorous activity.

Too much, too soon, and you can injure yourself. Or you will be too exhausted to continue, and you will give up. Neither one will lead you to a successful outcome.

So what do you do if you are no longer a kid, but you decide it is time for you to get into some kind of shape? The answer may not be what you would think. The best answer for you is resistance training.

Now, what is resistance training? There are many kinds of resistance training, but the kind that would be most familiar to you, and the kind that you could do and should do, is weight lifting.

Weight lifting, at any age, is the safest and most effective way to get in shape. And especially if you are getting older, stiffer, heavier, and out of shape, weight lifting may be ideal for you.

That may not seem logical at first glance, but here is why. One example of the benefits of weight training is found in the research done at the University of Arkansas. (Exercise training guidelines for the elderly. Evans WJ, Med Sci Sports Exerc. 1999 Jan;31(1):12-7.) This is one of many studies which showed the benefits of heavy weight training in all ages.

They studied the group that you might guess would be most prone to injury and least likely to be able to exercise. They picked elderly nursing home residents and had them do high intensity resistance training.

What the researchers found was that the frail elderly develop increased muscle mass and dramatically increased strength in a few short weeks. Further, they became more active in their daily lives after they got more fit.

They defined high intensity resistance training as movements involving greater than 60% of the one repetition maximum. For example, if the maximum that you could lift one time was 100 pounds, then high intensity resistance training would require you to lift at least 60 pounds.

Sixty percent of your one repetition maximum is enough resistance to cause muscle growth. It requires movement of muscle against resistance to cause muscle growth, and that is why most people get so little benefit from their treadmill workouts and why they often give up. Plodding on the treadmill does not stimulate muscle growth, and it will not give you the changes in your body you are hoping for.

What is true for the elderly is true for people of all ages. Resistance training in any form will give you all sorts of benefits. It increases muscle tone and it increases muscle mass. The increased tone gives women a shapelier figure and men a more powerful silhouette, and the increased mass burns calories and aids weight loss.

There are many forms of resistance training. Any exercise which will cause you to exert yourself at least 60 percent of your maximum exertion will do. But if you are out of shape it is very difficult to do a lot of resistance activities. Climbing trees might work well for you if you are already in excellent shape, but if not you have to find something that you can actually do. That is why weight training is the ideal resistance exercise for most people.

The weights come in all sizes, from the 8 ounce soup can in your cupboard to 150 pound dumbbells at the gym. The variety of exercises is infinite and limited only by your imagination. There are many excellent books, videos and magazines available on the subject.

The gains you make are easy to see, because the numbers are right there in front of you. So you don’t have to wonder if you are making gains. You will make gains, and you will see so yourself in a very few weeks. Especially in people who have let themselves get out of shape, weight lifting can bring dramatic changes in a very short period of time if done right.

And perhaps most importantly weight lifting can be fun. You will see after you try it. It is fun when you see yourself becoming strong and lean.