Faculty Collaboration Database

Exercise-induced insulin-like growth factor I system concentrations after training in women. Med Sci Sports Exerc 2013 Mar;45(3):420-8

Date

10/05/2012

Pubmed ID

23034644

DOI

10.1249/MSS.0b013e3182750bd4

Scopus ID

2-s2.0-84875212874 (requires institutional sign-in at Scopus site)   64 Citations

Abstract

INTRODUCTION: This study examined the effects of short-term physical training on the acute hormonal response (i.e., growth hormone, total and free insulin-like growth factor I [IGF-I], and IGF binding proteins [IGFBP]-1, IGFBP-2, and IGFBP-3) to resistance exercise (RE) in women.

METHODS: Forty-six women (20.3 ± 0.3 yr, mass = 64.1 ± 7.3 kg, height = 165.7 ± 1.0 cm) were randomly assigned to an endurance training (E), resistance training (R), combined training (R + E), or control (C) group for 8wk. Subjects completed a standardized bout of RE (six sets of back squats at 10 repetition maximum) before and after training. Blood samples were obtained at rest (PRE), after the third set, immediately postexercise (POST), and at 15 min and 30 min after exercise.

RESULTS: Acute RE significantly increased (P < 0.05) serum growth hormone (mean ± SD; change from PRE to POST = +10.9 ± 7.5 μg·L-1), total IGF-I (+66.1 ± 25.4 μg·L-1), IGFBP-1 (+2.5 ± 3.1 μg·L-1), IGFBP-2 (+86.0 ± 86.8 μg·L-1), and IGFBP-3 (+0.69 ± 0.25 mg·L-1) concentrations and decreased free IGF-I concentrations (-0.14 ± 0.21 μg·L-1). After 8 wk of training, total IGF-I concentrations were significantly increased (change in POST concentrations from week 0 to week 8 = +82.5 ± 120.8 μg·L-1), and IGFBP-1 concentrations were significantly decreased (-6.7 ± 13.6 μg·L-1) during exercise in groups that participated in resistance training (R and R + E); no significant changes were seen after E or C.

CONCLUSIONS: Participation in resistance training increased total IGF-I and reduced IGFBP-1 concentrations during acute RE, indicating exercise mode-specific adaptations in the circulating IGF-I system.

Author List

Gregory SM, Spiering BA, Alemany JA, Tuckow AP, Rarick KR, Staab JS, Hatfield DL, Kraemer WJ, Maresh CM, Nindl BC

MESH terms used to index this publication - Major topics in bold

Adult
Analysis of Variance
Female
Growth Hormone
Humans
Insulin-Like Growth Factor Binding Protein 1
Insulin-Like Growth Factor Binding Protein 2
Insulin-Like Growth Factor Binding Protein 3
Insulin-Like Growth Factor I
Muscle Strength
Muscle, Skeletal
Resistance Training
Running
Time Factors
Young Adult