If you are eating a low-fat diet and exercising regularly but still can’t seem to lose those last few pounds, you may need to take another look at your exercise routine.

Extension Nutritionist Dr. Robert Keith says there are four aspects to a complete fitness program.

"They are cardiovascular training, strength training, flexibility and hand-eye coordination," he says. "Cardiovascular exercises help your heart, strength exercises work your muscles, flexibility involves stretching, and eye-hand coordination has to do with reaction time."

Cardiovascular exercises, including walking, running, jogging, cycling, swimming and aerobics, help keep your heart healthy. Keith says at least 30 minutes of cardiovascular exercise a day, four or five times a week, is recommended.

"Some people are even advocating up to an hour of exercise each day," he says. "It doesn’t have to be continuous though. For the actual fitness benefit, an hour of continuous exercise is best, but from a calorie-burning perspective, it doesn’t matter. You can take an hour and break it into four 15-minute sessions and you’ll burn the same amount of calories if you exercise continuously for an hour."

Strength exercises are also important. Weight-bearing exercises can speed up your metabolism, strengthen your lower back and help keep your bones strong.

Strength exercises include weight lifting, push-ups, and pull-ups on a bar, says Keith. "Weight-bearing exercises increase your strength for everyday activities and support your back and abdomen. Really, a lot of back problems come from poor abdominal strength. As you get older, the strength exercises also help improve bone density. Weight lifting has a really positive effect on keeping your bones strong so you won’t develop osteoporosis, brittle bones, or bone fractures as you get older. That’s especially important for women."

The third area is flexibility.

"You can do anything from yoga to just simple things like walking to a door frame and doing arm stretches against the door, doing hip rotations or reaching down and touching your toes," he says. "Or if you can’t do it standing up, you can sit in a chair depending on how old you are and what your physical condition is. Flexibility is important for balance. It also helps you avoid injury by keeping your tendons and ligaments stretched out so you don’t get hurt as you get older."

Keith says the fourth and perhaps least important aspect is eye-hand coordination, or how well you can react with your eyes and hands.

"Golf or tennis will help you with that, or even just getting a ball and throwing it against a wall," he says. "Even video games are very good for eye-hand coordination. Those things help with reaction time."

Keith says the human body was made to move.

"When you exercise, you actually feel better," he says. "You have more energy and less stress and you sleep better. Studies have shown that if you exercise aerobically a little bit, it sends more blood to your brain and you actually think more clearly. So if you have a problem at the office, get out and walk for a few minutes and come back to it, and you may be able to solve the problem better."