title: Effects of β-Hydroxy-β-methylbutyrate Free Acid Ingestion and Resistance Exercise on the Acute Endocrine Response.
abstract: Objective. To examine the endocrine response to a bout of heavy resistance exercise following acute β-hydroxy-β-methylbutyrate free acid (HMB-FA) ingestion. Design. Twenty resistance trained men were randomized and consumed either 1 g of HMB-FA (BetaTor) or placebo (PL) 30 min prior to performing an acute heavy resistance exercise protocol. Blood was obtained before (PRE), immediately after (IP), and 30 min after exercise (30P). Circulating concentrations of testosterone, growth hormone (GH), insulin-like growth factor (IGF-1), and insulin were assayed. Data were analyzed with a repeated measures ANOVA and area under the curve (AUC) was analyzed by the trapezoidal rule. Results. The resistance exercise protocol resulted in significant elevations from PRE in testosterone (P < 0.01), GH (P < 0.01), and insulin (P = 0.05) at IP, with GH (P < 0.01) and insulin (P < 0.01) remaining elevated at 30P. A significant interaction was noted between groups in the plasma GH response at IP, which was significantly higher following HMB-FA compared to PL (P < 0.01). AUC analysis revealed an elevated GH and IGF-1 response in the HMB-FA group compared to PL. Conclusion. HMB-FA prior to resistance exercise augments the GH response to high volume resistance exercise compared to PL. These findings provide further support for the potential anabolic benefits associated with HMB supplementation.
authors: Institute of Exercise Science and Wellness, Sport and Exercise Science, University of Central Florida, Orlando, FL 32816, USA.
authors: Jeremy R
authors: JR
authors: Townsend
authors: Institute of Exercise Science and Wellness, Sport and Exercise Science, University of Central Florida, Orlando, FL 32816, USA.
authors: Jay R
authors: JR
authors: Hoffman
authors: Institute of Exercise Science and Wellness, Sport and Exercise Science, University of Central Florida, Orlando, FL 32816, USA.
authors: Adam M
authors: AM
authors: Gonzalez
authors: Institute of Exercise Science and Wellness, Sport and Exercise Science, University of Central Florida, Orlando, FL 32816, USA.
authors: Adam R
authors: AR
authors: Jajtner
authors: Institute of Exercise Science and Wellness, Sport and Exercise Science, University of Central Florida, Orlando, FL 32816, USA.
authors: Carleigh H
authors: CH
authors: Boone
authors: Institute of Exercise Science and Wellness, Sport and Exercise Science, University of Central Florida, Orlando, FL 32816, USA.
authors: Edward H
authors: EH
authors: Robinson
authors: Institute of Exercise Science and Wellness, Sport and Exercise Science, University of Central Florida, Orlando, FL 32816, USA.
authors: Gerald T
authors: GT
authors: Mangine
authors: Institute of Exercise Science and Wellness, Sport and Exercise Science, University of Central Florida, Orlando, FL 32816, USA.
authors: Adam J
authors: AJ
authors: Wells
authors: Institute of Exercise Science and Wellness, Sport and Exercise Science, University of Central Florida, Orlando, FL 32816, USA.
authors: Maren S
authors: MS
authors: Fragala
authors: Institute of Exercise Science and Wellness, Sport and Exercise Science, University of Central Florida, Orlando, FL 32816, USA.
authors: David H
authors: DH
authors: Fukuda
authors: Institute of Exercise Science and Wellness, Sport and Exercise Science, University of Central Florida, Orlando, FL 32816, USA.
authors: Jeffrey R
authors: JR
authors: Stout