J. Nagasawa et al., LONG-LASTING EFFECT OF TRAINING ON INSULIN RESPONSIVENESS IN THE RAT, International journal of sports medicine, 16(2), 1995, pp. 91-93
In vivo insulin sensitivity and responsive ness were assessed in rats
one day (Day 1), seven days (Day 7), and 3 weeks (Day 21) after cessat
ion of training, using a 2-stage sequential hyperinsulinemic euglycemi
c clamp technique (insulin infusion rate: 4.4 mU . kg(-1) . min(-1) an
d 26.4 mU . kg(-1) . min(-1)). The day after the last bout of exercise
, the glucose infusion rate (GIR-L: 4.4 mU-dose), which is an index of
insulin sensitivity, was significantly higher in the trained group (1
1.5 +/- 1.1 mg . kg(-1) . min(-1)) than in the control group (6.1 +/-
0.6 mg . kg(-1) . min(-1) p<0.01). Detraining decreased GIR-L signific
antly, to 7.4 +/- 0.5 (Day 7: p < 0.01) and 7.4 +/- 0.5 mg . kg(-1) .
min(-1) (Day 21: p < 0.05). Insulin responsiveness, assessed by respon
se to a 26.4 mU-dose of insulin (GIR-H), was also increased by trainin
g, from 21.8 +/- 1.2 mg . kg(-1) . min(-1) (control) to 32.9 +/- 1.2 (
Day 1, p < 0.01). Seven days after cessation of training period the le
vel was nearly identical (33.4 +/- 1.0 mg . kg(-1) . min(-1)) and rema
ined high 3 weeks after training (30.8 +/- 1.0: p < 0.01, vs control).
These data indicate that insulin responsiveness remains elevated for
3 weeks after training, although insulin sensitivity is reversed withi
n seven days. These results may be attributed to changes in body compo
sition or long-lasting changes in post-receptor mechanisms.