New Study Reveals How Quickly Strength Training Can Affect Fat Cells in Mice

Just seven days of strength training activated fat-burning processes and reduced visceral fat in obese mice, even before they experienced any weight loss, according to a new study published in Life Sciences.

Researchers at the State University of Campinas (UNICAMP), Brazil, investigated how strength training affects fat tissue during the early stages of exercise, independently of changes in body weight.

The experiment involved male mice, some of which developed obesity after consuming a high-fat diet. The obese mice were divided into sedentary and exercise groups, with both groups continuing the same diet throughout the study.

The exercising mice completed seven strength training sessions by climbing a 70-centimetre staircase while carrying weights attached to their tails. Each session involved 20 climbs, with loads equivalent to 70% of their maximum capacity.

Researchers focused on mesenteric adipose tissue, a type of visceral fat surrounding the intestines. Excessive visceral fat is associated with inflammation and metabolic problems.

Despite no changes in overall body weight, exercising mice had less mesenteric fat and smaller fat cells than sedentary mice.

Further molecular analysis revealed that strength training activated processes involved in lipolysis, the breakdown of stored fat. Researchers observed increased interaction between ABHD5 and ATGL, proteins involved in breaking down triglycerides stored within fat cells.

The exercise intervention also reduced expression of the Scd1 gene, which contributes to fat production, suggesting that exercise may influence both fat breakdown and storage.

According to the researchers, these findings challenge the perception that exercise produces health benefits only when visible weight loss occurs. Strength training may initiate beneficial metabolic changes before changes appear on the weighing scale.

Future studies will investigate whether these early molecular changes persist with longer training periods and how exercise affects other fat deposits, including those surrounding the heart.

REFERENCE: Diego Gomes de Melo, et al.; Strength training induces ABHD5-ATGL axis to counteract mesenteric fat accumulation in obese Swiss mice. Life Sciences, 2026; 401: 124546 DOI: 10.1016/j.lfs.2026.124546