WASHINGTON -- Your overweight and obese clients may have to work harder than lean people to see results from strength training, according to a recent study published in the Journal of Strength and Conditioning Research.

“Despite similar relative muscle size increases, relative and allometic strength gains were less among overweight than normal weight [study subjects],” the authors write. “These findings indicate the short-term relative and allometric muscle strength response to resistance training may be attenuated among adults who are overweight and obese.”

However, your overweight clients shouldn’t give up, as they still receive health benefits such as weight loss and improvements in cardiopulmonary physical fitness.

Researchers looked at 687 adults aged 18 to 39 and measured their body fat using magnetic resonance imaging. The volunteers performed 12 weeks of 45- to 60-minute strength workouts, working the biceps and triceps.

While all subjects gained strength and muscle, overweight and obese volunteers gained 4 percent to 17 percent less than those subjects of normal weight.