By Judy Rupp, Columnist

Charles, 69, and Maggie, 28, often work out side-by-side on weight machines at the health club.

Once reserved mainly for body builders, resistance training with weights is now recognized as an important component of fitness. A long-time runner, Charles understands the role of resistance training in heading off the loss of muscle mass and strength associated with aging. Maggie, who does aerobics three times a week, lifts weights on the off days to assist in weight

Josh, a body builder who lifts bar bells nearby, regularly stops on his way out of the health club to buy protein supplements. But what about Charles and Maggie? Do they need extra protein as well?

A major component of muscle, protein is essential to building, maintaining and repairing muscle cells. But you can’t build muscle by eating protein. To do that, you have to exercise, breaking down muscle fibers and then rebuilding them-bigger-through protein synthesis.

Bodybuilders have long believed eating plenty of protein is important to muscle building. Nutritionists haven’t always agreed, but studies indicated physically active persons, particularly those doing resistance training, probably require at least some extra protein.

The USDA recommends .8 grams of protein per kilogram of body weight a day. That’s about 40 grams for a female and 55 to 70 for a male. The typical American gets far more than that – about 100 grams a day. And most athletes who eat a varied diet have no worry about getting enough protein.

There are some exceptions: weight lifters or triathletes following a very heavy exercise schedule; those trying to lose weight by drastically cutting calories while exercising at a high level; and individuals with special needs for muscle growth or maintenance such as growing adolescents or older persons.

Using nitrogen balance studies, re-searchers found runners or other endur-ance athletes training 12 hours a week or more for at least five years required 1.37 grams of protein per kilogram of lean body weight a day compared to .73 grams per day for sedentary persons.

Meat and animal products are a good source of protein because they have a full complement of all of the essential amino acids that make up protein. Generally, however, red meat comes with high levels of saturated fat.

Athletes trying to build bulk are advised to seek lean sources such as fish, chicken, eggs, dairy products and lean cuts of pork and beef. Six ounces of salmon provide almost as much protein (34 grams) as a Porterhouse steak (36 grams) but only 4 grams of saturated fat compared to 16 for the steak.

“Complete” proteins – those containing all the amino acids needed for protein synthesis – tend to come from animal sources. Even so, vegetarians and vegans can get all the proteins they need from beans, lentils, chick peas, nuts, whole grains, fruits and vegetables.

Whatever exercise you do, it’s important to get plenty of protein to keep your muscles strong and in good repair. According to a NIH study of men and women in their 70s, the greatest loss of muscle mass was found among those who ate the least amount of protein.

Timing may be important. In one study of elderly males given a 12-week program of resistance training, muscle growth occurred when protein was in-gested within an hour of the workout, but no significant growth was noted when the protein was eaten more than two hours after exercise.

While weight trainers may claim extra protein, in the form of protein shakes or energy bars, is the key to pumping up the muscles, it’s important not to overdo it. There’s no evidence more than 2.0 grams of protein per kilogram of body weight is beneficial to building muscle mass, and most nutritionists advise keeping protein intake to 15 to 20 percent of calories.

When excess protein is ingested, it is broken down and eliminated as urine, and that can put a strain on the kidneys. A high protein diet is associated with dehydration and is unsafe for anyone with chronic kidney disease.

Rupp is information and assistance case manager with the Northern Oklahoma Development Authority Area Agency on Aging.