2.2. Eligibility Criteria:
Studies were selected by applying the following
Population-Intervention-Comparator-Outcomes-Study design (PICOS)
criteria (21): 1) healthy subjects received oral HMB supplementation, as
a nutritional strategy before and after exercise; 2) original
randomized-controlled trial researches and 3) reporting at least one
outcome measure of hormones (cortisol and testosterone). Studies were
not conducted by using multiple supplementations, (HMB in conjunction
with other supplement like creatine (20), arginine, lysine (22) and
adenosine monophosphate (23)). There were restrictions on the performed
post-exercise and studies that assessed the acute effect of HMB on the
hormonal response (24, 25).