Format

Send to

Choose Destination
Med Sci Sports Exerc. 2005 Nov;37(11):1990-7.

Protein ingestion prior to strength exercise affects blood hormones and metabolism.

Author information

1
Department of Biology of Physical Activity, University of Jyväskylä, Finland.

Abstract

PURPOSE:

The effects of protein consumption before strength training session on blood hormones, energy metabolites, RER, and excess postexercise oxygen consumption (EPOC) were examined.

METHODS:

Ten resistance-trained young men consumed either a 25 g of whey and caseinate proteins (PROT) or a noncaloric placebo (P) in a liquid form 30 min before a heavy strength training session (STS) in a crossover design separated by at least 7 d. STS lasted 50 min and included 5 x 1 RM squats, 3 x 10 RM squats and 4 x 10 RM leg presses with 2-, 3-, and 2-min recoveries, respectively. A protein-carbohydrate supplement was consumed after STS in both trials. Venous blood samples were collected before, during, and after STS and oxygen consumption before and after STS.

RESULTS:

Serum growth hormone (GH), testosterone, and free fatty acids (FFA) were significantly (P < or = 0.05) higher in P compared with PROT 5 min after an STS. The calculated area under curve (AUC) of the serum insulin response during an STS was significantly (P < 0.001) higher in PROT compared with P. The EPOC value from 90 to 120 min after an STS was significantly greater in the PROT condition compared with P (P = 0.01), and PROT treatment had a significantly higher RER 2 h postexercise (P = 0.04). The AUC of serum FFA during STS correlated significantly and negatively with RER 10-30 min after STS (r = -0.53, P = 0.02).

CONCLUSIONS:

Consuming 25 g of whey and caseinate proteins 30 min before an STS significantly decreases serum GH, testosterone, and FFA levels, and increases serum insulin during an STS. Furthermore, the pre-STS protein increased EPOC and RER significantly during 2-h recovery after STS.

PMID:
16286871
[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Wolters Kluwer
Loading ...
Support Center