June 2, 2010 — Little particles within the blood not only reveal the “metabolic signature” of fitness, but indicate at how new sports drinks or drugs might offer assistance individuals more viably burn fat.

Using modern technology, Massachusetts General Clinic analysts Gary Lewis, MD, Robert Gerszten, MD, and colleagues followed more than 200 small particles in the blood.

The atoms are the end products — metabolites — created as the body goes around its trade of converting sugars, fats, proteins, and amino acids into energy.

When Lewis’s team looked at the metabolite profiles of relatively sound, middle-aged, overweight men and women before and after a prescribed 10-minute exercise stretch test, they got a surprise. Those who were more fit had a very different metabolite profile than those who were not fit, revealing a “metabolic signature” of fitness.

“People who are more fit are able tomobilize the fuel source in fat better than those who are less fit,” Lewis tells WebMD. “That’s an awfully curiously finding. Certain individuals will burn fat much more heartily than others.”

That goes tenfold for marathon runners. When the analysts analyzed blood metabolites in 25 individuals who had fair run the Boston Marathon, they found that they had gone into an intense fuel-burning mode that expended fat a thousand times more viably. Interests, those with above-average finish times had fewer harmful metabolites in their blood than those who wrapped up with below-average times.

The increased capacity to burn fat and other fills, indeed in normal people, proceeded for at least an hour after they stopped exercising. And fat burning wasn’t the only positive effect. Exercise moreover acted like an antioxidant, diminishing oxidative stretch in the body.

Opposite findings come from studies of stationary people. Lewis says their metabolic profile demonstrates that their bodies get better and way better at storing up fat saves.

“With work out you tap into all these fills within the body and put yourself into a fuel-burning mode,” Lewis says. “Shockingly, the adjust in a lot of individuals is tipped toward over-storage mode and away from this stamped metabolic reaction seen in indeed a brief bout of work out.”

Fitness in a Bottle?

It’s not however clear from the studies what it is that produces a person more fit.

“What we still are sorting out is, are these fit people inherently diverse based on genetics — people who are implied to be lean and who when they walk over the road burn more fat? Or by progressing to the gym three times a week, have they been able to change their metabolism to burn fat more robustly?”

A tantalizing indicate comes from advance considers suggesting that the metabolites seen after exercise aren’t just by-products of fuel burning. They may play an active role in advancing fitness.

“When we exposed muscle cells to some of the metabolites that increment after exercise, we found they turned on an critical gene that controls the ability to use glucose [sugar] in fats,” Lewis says. “So work out through these little particles that are discharged can invigorate expression of qualities that are imperative to our digestion system.”

Undoubtedly, one quality actuated by these exercise-associated atoms is nur77, a gene that helps control how the body burns or stores sugar and fat.

“In case you look at a sports drink name, you’ll see the drink contains handfuls of small particles. But think of supplementing that drink with all these atoms we now know the body uses up during exercise,” Lewis says. “So you can imagine we could be able to use these findings to create the next generation of sports drinks.”

And by examining the metabolic profiles of people with heart disease and other conditions, the researchers too trust to learn whether certain metabolites — or drugs that mirror their action — can be therapeutic.

But if all we want to do is lose weight, all the small atoms in the world might not be sufficient, cautions Andrew S. Greenberg, MD, director of the corpulence and metabolism research facility and the center on aging at Tufts University.

“Fair since you have these metabolites does not mean that in case you put them into your muscles you would be fit,” Greenberg tells WebMD. “You do not just get on a treadmill and burn fat. It takes a long-term process of resetting the indoor regulator of how your body reacts to work out.”

Work out is fair one part of the fitness equation, Greenberg says. Diet is the other.

But Joshua C. Munger, PhD, partner teacher of organic chemistry and biophysics at Rochester College, notes that the Lewis consider is breaking modern ground in making a difference scientists understand the benefits of wellness.

“We get it that it is nice for you to induce bounty of work out, but it isn’t clear exactly where the benefit lies,” Munger tells WebMD. “The alluring address raised by the Lewis think about is whether these metabolites may play a causal role in modulating the pathways driving to fitness.”

The Lewis/Gerszten study shows up in the May 26 online issue of Science Translational Medication.