Research

Hormonal

Plasma IL-15 protein levels increase acutely after resistance exercise but do not change chronically with training and are not associated with variability in muscle responses.

Measuring blood IL-15 levels is not a useful predictor of who will gain muscle from resistance training. Focus on consistent training and nutrition rather than trying to manipulate circulating IL-15 levels.

GoodRefutesHIGH confidence
Plasma IL-15 protein was significantly increased (P < 0.05) immediately after acute resistance exercise but did not change with training and was not associated with variability in muscle responses with training.
Steven E. Riechman et al. · Journal of Applied Physiology · 2004

Why this rating

Controlled measurement of plasma levels before and after training.

Source

Association of interleukin-15 protein and interleukin-15 receptor genetic variation with resistance exercise training responses

Steven E. Riechman et al. · Journal of Applied Physiology · 2004

DOI 10.1152/japplphysiol.00491.2004

cohort · n=153Cited 230×
Read the paper
DOI resolved against Crossref · corpus check 2026-06-10

This is one finding among thousands. Every one is graded and traced to its source, so you can see what the evidence actually supports. Browse the research →