Tat-Beclin1 Plus Training Raised Old Mice's Grip by 42%

Jeff's Daily Pick. In 23 month old male mice, a month of treadmill training plus the autophagy peptide Tat-Beclin1 raised grip strength 41.7% and endurance 66.7% (Physiological Reports). Training alone barely moved grip (+1.4%) but lifted endurance 53.9%. Only 31 mice, all male.

In the United States, researchers at Rowan University in New Jersey, with colleagues at the Children's Hospital of Philadelphia, the Oklahoma Medical Research Foundation and the University of Iowa, published a mouse study in Physiological Reports in October 2026. The question: does Tat-Beclin1, a lab peptide that switches on autophagy, the process cells use to break down and recycle worn parts, change what endurance training does for old muscles?

How it was tested

The mice were 23 months old, roughly 69 in human years according to the authors, and all male. They were randomly split into four groups for one month: untreated controls (5 mice), Tat-Beclin1 injections twice a week (9), treadmill running three times a week at 70% of maximal speed (9), or both (8). Grip strength, time to exhaustion on a treadmill and balance on a rotating rod were measured before and after.

The results

Measured against each group's own starting point, grip strength rose 41.74% with the combination and 20.43% with the peptide alone. Training alone (+1.37%) and the controls (down 16.51%) showed no significant change. Endurance rose 66.67% with the combination, 53.87% with training alone and 37.41% with the peptide alone, while the controls trended down 21.17%. Balance improved by 60.28% only in the combined group; the controls lost 22.41%.

The statistics point to effects that add up, not to synergy. Both the peptide and training had significant effects of their own, but there was no significant interaction between them. Markers of autophagy in the muscle barely changed, and the combination unexpectedly raised acute inflammatory proteins such as haptoglobin and orosomucoid-1.

For human data on what lifts strength with training, see our piece on protein and resistance training. For another single target tested in old mice, see the SRSF1 lifespan study.