Effect of single wrist exercise on fibroblast growth factor-2, insulin-like growth factor, and growth hormone

Anabolic effects of exercise are mediated, in part, by fibroblast growth fa ctor-2 (FGF-2), insulinlike growth factor-I (IGF-I), and growth hormone (GH ). To identify local vs. systemic modification of these mediators, 10 male subjects performed 10 min of unilateral wrist-flexion exercise. Blood was s ampled from catheters placed in basilic veins of both arms. Lactate was sig nificantly increased only in the exercising arm. FGF-2 decreased dramatical ly (P< 0.01) in both the resting (from 1.49 +/- 0.32 to nadir at 0.11 +/- 0 .11 pg/ml) and exercising arm (1.80 +/- 0.60 to 0.29 +/- 0.14 pg/ml). Small but significant increases were found in both the resting and exercising ar m for IGF-I and IGF binding protein-3 (IGFBP-3). GH was elevated in blood s ampled from both the resting (from 1.04 +/- 0.68 to a peak of 2.57 +/- 0.53 ng/ml) and exercising arm (1.04 +/- 0.66 to 2.43 +/- 0.42 ng/ml, P< 0.05). Unilateral wrist exercise was not sufficiently intense to increase circula ting lactate or heart rate, but it led to systemic changes in GH, IGF-I, IG FBP-3, and FGF-2. Low-intensity exercise involving small muscle groups can influence the circulating levels of growth factors.