Fettoxidation efter träning; påverkan av intensitet och varaktighet

[King Grub]

Post exercise fat oxidation may be of importance for exercise prescription aimed at optimizing fat loss. We examined the effects of exercise intensity, duration and modality on post-exercise oxygen consumption (VO2) and substrate selection/respiratory exchange ratio (RER) in healthy individuals. Three experiments (n = 7 for each) comparing: A) short (SD) vs. long duration (LD) ergometer cycling exercise (30 min vs. 90 min, respectively) matched for intensity; B) low (LI) vs. high intensity (HI) cycling (50 % vs. 85 % of VO2max, respectively) matched for energy expenditure; and C) continuous (CON) vs. interval (INT) cycling matched for energy expenditure and mean intensity. All experiments were administered by cross-over design. Altering exercise duration did not affect post-exercise VO2 or RER kinetics (P >0.05). However, RER was lower and fat oxidation was higher during the post-exercise period in LD vs. SD (P <0.05). HI vs. LI resulted in a significant increase in total post-exercise energy expenditure and fat oxidation (P <0.01). Altering exercise modality (CON vs. INT) did not affect post-exercise VO2, RER or fat oxidation (P >0.05). These results demonstrate that post-exercise energy expenditure and fat oxidation can be augmented by increasing exercise intensity, however, these benefits cannot be exploited by undertaking interval exercise (1 min:2 min work:recovery ratio), when total energy expenditure, duration and mean intensity remain unchanged. In spite of the apparent benefit of these strategies, the amount of fat oxidized after exercise may be inconsequential compared with that oxidized during the exercise bout.

Post-exercise fat oxidation: effect of exercise duration, intensity and modality', International Journal of Nutrition and Exercise Metabolism. 2009 (in press).

http://hk.humankinetics.com/ijsnem/viewarticle.cfm?jid=tm64t8Tnpp24c8NMgr23n3gJgg8738 W6qf747674gf26&view=prev&aid=17010&site=tm64t8Tnpp24c8NMgr23n3gJgg8738W6qf747674gf26

[Kimball]

Så i slutänden kvittar det vilket intensitet man kör, fettoxidationen jämnar ut sig så länge energiåtgången förblir densamma? Om jag inte misstolkar det hela.