Maintaining Normal Levels of Testosterone May Help Soldiers Avoid Muscle and Weight Loss During Strenuous Operations

For more information, contact our Media Relations Manager, Ted Griggs, 225-763-2862 or our Communications Director, Lisa Stansbury, at 225-763-2978. Our news email box is also available at

Released: Monday, December 09, 2019

Baton Rouge, Louisiana — A new, first-of-a-kind study suggests that maintaining soldiers’ testosterone at normal levels can help prevent the muscle and weight loss that often take place during strenuous training or combat operations.

During strenuous training and combat operations, soldiers burn through more than one-and-a-half times the calories than the average American does each day. However, soldiers consume far fewer calories than their bodies are burning during those strenuous events, resulting in large calorie deficits.

“As a result of prolonged operational stress, the soldiers’ testosterone and other hormone levels decline. They lose both fat and muscle mass and may be more injury-prone,” said Jennifer Rood, PhD, and associate executive director of Cores and Resources at LSU’s Pennington Biomedical Research Center. “They experience mental fatigue that can affect memory and concentration and make them less alert. Overall, the soldiers’ combat readiness declines.”

A new study, published in the journal EBioMedicine, found that supplemental testosterone can help maintain normal hormone levels, prevent muscle loss and minimize weight loss during prolonged calorie deficits. In collaboration with scientists from the U.S. Army Research Institute of Environmental Medicine (USARIEM), University of California at Berkeley, Defense Research and Development Canada, and Harvard Medical School, Pennington Biomedical researchers studied 50 men, aged 18-39, of normal weight. The Optimizing Performance for Soldiers study imitated the severe exercise- and diet-induced calorie deficits that are typically observed during military field operations.

During the intensive physical activity phase of the study, the volunteers consumed only 45 percent of the calories they burned. Half of the study participants received a placebo and half received weekly testosterone injections. While members of both groups lost the same amount of fat, the participants in the testosterone group actually gained lean body mass and lost less weight overall.

“We are very excited about these findings and are extremely thankful to the study participants and staff for all of their efforts. The findings from our study provide rationale for further investigation of practical and safe pharmacologic interventions to offset muscle loss experienced by soldiers during periods of unavoidable, severe calorie deficit,” said Stefan Pasiakos, PhD, Deputy Chief of the Military Nutrition Division at USARIEM and the lead scientist who conceived the experiment. “The study results will help the Army improve readiness and further optimize the performance of soldiers.” 

This work was supported by the U.S. Department of Defense.



About LSU's Pennington Biomedical Research Center

LSU's Pennington Biomedical Research Center is at the forefront of medical discovery as it relates to understanding the triggers of obesity, diabetes, cardiovascular disease, cancer and dementia. The center conducts basic, clinical and population research, and is affiliated with Louisiana State University. The research enterprise at Pennington Biomedical includes over 450 employees within a network of 40 clinics and research laboratories, and 13 highly specialized core service facilities. Its scientists and physician/scientists are supported by research trainees, lab technicians, nurses, dietitians and other support personnel. Pennington Biomedical is located in state-of-the-art research facilities on a 222-acre campus in Baton Rouge, Louisiana.