Ever watch someone bench press a ridiculous amount of weight but not look quite like The Rock? Or hit the gym every day and still have a beer belly? It’s not an illusion — some research suggests people can be in shape even if they don’t quite look the partThe “fit but fat” concept revisited: population-based estimates using NHANES. Duncan, G.E. Department of Epidemiology, Nutritional Sciences Program, University of Washington, Seattle, WA. International Journal of Behavioral Nutrition and Physical Activity, 2010 May 24;7:47.. But a more recent study found that being overweight actually puts people at greater risk of dying from heart disease Are Metabolically Healthy Overweight and Obesity Benign Conditions? A Systematic Review and Meta-analysis. Kramer, C.K., Zinman, B., Retnakaran, R. Annals of Internal Medicine 2013 December 3;159(11):758-69.. The new findings complicate the “fit but fat” issue, and imply that even medical professionals can’t always determine someone’s health status so easily.

(Over)weight Lifting — Why It Matters

Scientists behind the new research reviewed a bunch of studies conducted since the 1950s and found that people who had a higher-than-recommended body mass index (BMI) were more likely to die from heart disease compared to people with normal BMIs Are Metabolically Healthy Overweight and Obesity Benign Conditions? A Systematic Review and Meta-analysis. Kramer, C.K., Zinman, B., Retnakaran, R. Annals of Internal Medicine 2013 December 3;159(11):758-69.. Those findings held true even when the researchers compared overweight participants who were metabolically healthy (as in, they didn’t have high cholesterol or blood pressure) to normal-weight participants who were also metabolically healthy.

That research comes on the heels of another, highly publicized, study that found people with higher-than-average BMIs actually lived longer than people with normal BMIs. Meanwhile, other research from the past few years suggests a small percentage of U.S. adults are both in shape and overweightThe “fit but fat” concept revisited: population-based estimates using NHANES. Duncan, G.E. Department of Epidemiology, Nutritional Sciences Program, University of Washington, Seattle, WA. International Journal of Behavioral Nutrition and Physical Activity, 2010 May 24;7:47..

The scientists who led the new study say earlier studies came to faulty conclusions possibly because they compared healthy obese people to unhealthy obese people; because they missed signs of diabetes or hypertension in overweight participants; or because they only studied the participants for short time periods.

Another way to explain the idea that someone can be overweight but otherwise healthy is that what’s on the scale may not be the most important factor when measuring good health. Some scientists suggest lack of exercise might raise the risk of heart disease more than excess body fat. In one study with 906 women, researchers found that participants with lower levels of fitness showed a clearer connection to cardiovascular problems than those who were overweight (measured by BMI)Being fit is more important than being fat for women and heart disease. Spurgeon, D. British Medical Journal, 2004 September 18; 329(7467): 644.. Other health experts say those who are less-than-ripped but still fit may have a lesser risk for cardiovascular disease than their skinny-but-sedentary peers. Ultimately, fitness capacity may be more critical than body mass index to prevent heart disease risk.

It’s also possible that, when it seems that the scale is stubbornly stuck, all that exercising may be fueling an appetite that leads to consuming too many calories. Another common setback: Doing the same workout over and over may no longer challenge the body.

Chubby Competition — The Answer/Debate

Many studies have shown a positive correlation between working out and better overall healthPhysical inactivity and mortality risk. Kokkinos, P, Sheriff, H, Kheirbek, R. Cardiology Department, Washington DC Veterans Affairs Medical Center, Washington, DC. Cardiology Research and Practice, 2011 Jan 20;2011:924945.. Yet regular exercise isn’t the only answer to dodging every health risk. If we tip the scale despite being a total gym rat, it’s a good idea to try shedding some excess pounds— through plan B. It’s never too late to clean up that diet, since obesity may lead to cardiovascular problemsThe impact of obesity on cardiovascular disease risk factors and subclinical vascular disease: the Multi-Ethnic Study of Atherosclerosis. Burke, G.L., Bertoni, A.G., Shea, S., et al. Division of Public Health Sciences, Wake Forest University School of Medicine, Winston-Salem, North Carolina. Archives of Internal Medicine, 2008 May 12;168(9):928-35..

The big-bottomed line? Even if we’re exercising, we can still carry some extra baggage. Exercise burns calories, but at the end of the day, stay mindful of how many calories are taken in, or if that workout regimen needs some variation. And remember, being fit isn’t all about appearances, and the benefits of working out are more than skin deep.

Do you usually assume that someone who appears to be overweight can’t possibly be physically fit? Let us know in the comments below.

Photo by Ben Draper

This article has been read and approved by Greatist Expert Vicki Vara.

This article originally posted February 2012. Updated December 2013.