News

Exercise Smarter, Not Harder: Metabolic Testing at Cabarrus Family Medicine

August 25, 2005 – “Are you having trouble losing weight even though you exercise regularly?” This is the catchphrase of the flyer that Dr. Mark Robinson is passing out to recruit participants for a weight loss study. This same question is asked to those who are interested in signing up for metabolic testing, a new service that CFM has recently begin offering. Not surprisingly, these two projects are connected.

CFM has recently hired Mike Lepp, MS, an exercise physiologist who consults with clients on performance, fitness and athletic training, and weight management. He has worked with everyone from the average person who wants to lose a few pounds and get in shape to top world athletes trying to reach peak performance, including Tour de France podium finishers and Olympic medallists.

But what Mike has in his bag of medical tricks is no ordinary eat-less-fat-and-exercise-more fitness plan. Mike uses a metabolic test to be able to determine the exact heart rate at which each of his clients needs to be exercising to most effectively lose weight. This test determines the patient’s precise response to exercise.

What Dr. Robinson wants to study is how much more effective Mike’s approach is than the exercise prescription provided by the American College of Sports Medicine and typically recommended by a family doctor: Take 220 minus your age to get your maximum heart rate. Then exercise at 60-80% of that rate to lose weight and improve health.

Dr. Robinson and co-investigators Kevin Crosby, B.; Allen Dobson, MD; Daniel Rosenberg, MD; Mike Lepp, BS, MS; Kevin Burroughs, MD; Tonda Gridley, RD, LDN, CDE; and Cole Barton, PhD have formed the hypothesis that the metabolic test will help participants lose at least eight more pounds than they normally would.

To find out, the study participants will be broken up into three groups. The first will exercise according to the results from their metabolic test and can keep up with their heart rate using a monitor; the second according to the standard formula recommendation using the participants’ age and a heart rate monitor; and the third according to the standard formula but checking their pulse to monitor heart rate. All subjects will be given the same simple diet sheet to follow and are not allowed to be on any other diet program during the test period.

Each participant will be monitored for twelve weeks, with check-ins every week for the first three weeks and then every three weeks after. There will also be a follow-up six months after the participant has completed the program. Both weight and waist size will be checked at each visit to gauge weight loss.

If you are interested, you must be female, age 25-45 and be able and willing to exercise regularly and follow the study diet and exercise for the duration of the study. According to the study abstract, “There are significant gender differences in weight loss. Accordingly, for this first study, only female subjects will be used.”

You are not eligible if you have any poorly controlled medical condition (high blood pressure, asthma, etc.), have diabetes or thyroid problems, use tobacco daily, or are unable or unwilling to exercise.

Not only will all clinic visits and procedures be free of charge for the study, but patients will also receive a coupon for a free club membership to a participating exercise facility for twelve weeks.

All metabolic tests, including those for the study, will be performed in the Concord office. Mike

Lepp will also be operating out of the Concord office.

Mike will be administering the metabolic test for the study, in addition to his regular patients. Participants will be tested on a treadmill while wearing a special neoprene mask attached to a metabolic analyzer. They will exercise to exertion while the mask computes the volume of oxygen that is consumed. This can then be converted to determine the metabolic rate or at what levels of exercise the body burns fat and at what levels the body burns sugar.

In order to lose weight, the exerciser ideally wants to burn fat, but what Mike’s test results have shown is that oftentimes at higher levels of intensity, some people are actually burning sugar. In this case, Dr. Robinson says, “they are just burning the glycogen in their muscles.” Eventually, as the muscles run out of the stored sugar, they will reach their anaerobic threshold and this will cause muscle fatigue. “The body will just stop. The muscles won’t work anymore. This is what happens when endurance athletes ‘hit the wall,’” he says.

According to the study background, “Most patients are unaware that fat burning usually occurs at lower heart rate levels. Calorie counters on exercise machines at health clubs clearly send the message that the more intense the exercise the more calories are burned. These machines entice the obese patient to exercise at higher and higher levels which increases the risk of injury and abandonment of exercise altogether.”

What the metabolic test results reveal are the exact levels of intensity where your body burns the most fat. The test results print in graph format, so you can also see those “no-no” zones – the times where your body is burning sugar, instead.

For Mike, this is also insight into how to help athletes improve their performance levels. For instance, a marathon runner might be burning fat at a given heart rate but switches over to burning sugar at anything above this rate. This is an athlete’s anaerobic threshold or “redline.” For endurance purposes, then, the runner cannot work above this redline level. So the goal for Mike is to get that maximum fat-burning heart-rate level to increase (a.k.a., increase the threshold), which would mean the runner could endure at a faster rate, thus being more likely to win the race! 

Dr. Robinson has big expectations for the success of metabolic testing: “This will offer patients a clear road map on how to exercise to improve their health. It will help us encourage physical activity, which has tremendous benefits to cardiovascular health and disease prevention. Anything we can do [as family medicine providers] to encourage more frequent and safe exercise is good. Disease prevention is one of the basic principles of family medicine.”

If you are interested in the study, contact the study coordinator, Debi Wright, at 704-721-7427. If you are interested in having your own metabolic profile determined, call the CFM – Concord office at 704-786-6521 to make an appointment.