Title |
Effects of a single dose of N-Acetyl-5-methoxytryptamine (Melatonin) and resistance exercise on the growth hormone/IGF-1 axis in young males and females
|
---|---|
Published in |
Journal of the International Society of Sports Nutrition, May 2022
|
DOI | 10.1186/1550-2783-4-14 |
Pubmed ID | |
Authors |
Erika Nassar, Chris Mulligan, Lem Taylor, Chad Kerksick, Melyn Galbreath, Mike Greenwood, Richard Kreider, Darryn S Willoughby |
Abstract |
Melatonin and resistance exercise alone have been shown to increase the levels of growth hormone (GH). The purpose of this study was to determine the effects of ingestion of a single dose of melatonin and heavy resistance exercise on serum GH, somatostatin (SST), and other hormones of the GH/insulin-like growth factor 1 (IGF-1) axis. Physically active males (n = 30) and females (n = 30) were randomly assigned to ingest either a melatonin supplement at 0.5 mg or 5.0 mg, or 1.0 mg of dextrose placebo. After a baseline blood sample, participants ingested the supplement and underwent blood sampling every 15 min for 60 min, at which point they underwent a single bout of resistance exercise with the leg press for 7 sets of 7 reps at 85% 1-RM. After exercise, participants provided additional blood samples every 15 min for a total of 120 min. Serum free GH, SST, IGF-1, IGFBP-1, and IGFBP-3 were determined with ELISA. Data were evaluated as the peak pre- and post-exercise values subtracted from baseline and the delta values analyzed with separate three-way ANOVA (p < 0.05). In males, when compared to placebo, 5.0 mg melatonin caused GH to increase (p = 0.017) and SST to decrease prior to exercise (p = 0.031), whereas both 0.5 and 5.0 mg melatonin were greater than placebo after exercise (p = 0.045) and less than placebo for SST. No significant differences occurred for IGF-1; however, males were shown to have higher levels of IGFBP-1 independent of supplementation (p = 0.004). The 5.0 mg melatonin dose resulted in higher IGFBP-3 in males (p = 0.017). In conclusion, for males 5.0 mg melatonin appears to increase serum GH while concomitantly lowering SST levels; however, when combined with resistance exercise both melatonin doses positively impacts GH levels in a manner not entirely dependent on SST. |
Twitter Demographics
Geographical breakdown
Country | Count | As % |
---|---|---|
United States | 2 | 25% |
Mexico | 1 | 13% |
Nigeria | 1 | 13% |
Unknown | 4 | 50% |
Demographic breakdown
Type | Count | As % |
---|---|---|
Members of the public | 8 | 100% |
Mendeley readers
Geographical breakdown
Country | Count | As % |
---|---|---|
Spain | 1 | 2% |
South Africa | 1 | 2% |
Brazil | 1 | 2% |
Unknown | 46 | 94% |
Demographic breakdown
Readers by professional status | Count | As % |
---|---|---|
Researcher | 9 | 18% |
Student > Bachelor | 8 | 16% |
Student > Doctoral Student | 7 | 14% |
Student > Master | 7 | 14% |
Student > Postgraduate | 4 | 8% |
Other | 9 | 18% |
Unknown | 5 | 10% |
Readers by discipline | Count | As % |
---|---|---|
Medicine and Dentistry | 13 | 27% |
Sports and Recreations | 10 | 20% |
Agricultural and Biological Sciences | 6 | 12% |
Psychology | 3 | 6% |
Business, Management and Accounting | 2 | 4% |
Other | 7 | 14% |
Unknown | 8 | 16% |