Recent U.S. studies say creatine may help build muscle mass even without formal physical training.

Researchers reported that the supplement boosted strength and lean tissue on its own, without exercise.

The article says participants saw physical changes even when they were not lifting weights or doing cardio.

Trials described added lean tissue without a gym routine and higher power on basic movement tests.

The piece says creatine acts on cellular energy, which it offers as the reason for those changes.

It still calls regular exercise the usual path to fitness, and says results vary with diet and biology.

Clinicians in the article advise caution and say people should talk with a doctor before starting it.

Further trials are expected to look at long-term safety in adults who are not exercising.

Read the full story on the creatine findings and the limits researchers place on the results.