Related Experiment Video
Updated: Aug 14, 2026

A Chronic High-Intensity Interval Training and Diet-Induced Obesity Model to Maximize Exercise Effort and Induce Physiologic Changes in Rats
Published on: April 28, 2023
Impact of high- and low-intensity targeted exercise training on the type of substrate utilization in obese boys
F Brandou1, A M Savy-Pacaux, J Marie
1Service central de physiologie Clinique, Unité CERAMM (Centre d'Exploration et de Réadaptation des Anomalies Métaboliques et Musculaires), CHU Lapeyronie, 34295 Montpellier Cedex 5, France. fredbrandou@yahoo.fr
Background:
We assessed the effect of two programs combining a hypocaloric diet with low-intensity (LI) or high-intensity (HI) exercise training, during two months, on substrate utilization at exercise in obese children.
Methods:
Fifteen obese boys participated in a combined program of exercise and caloric restriction-induced weight loss (diet starting two weeks before the training program). The maximal fat oxidation point (Lipox max) was determined to individualize exercise training. Training consisted of cycling at either LI (Lipox max) for seven children or HI (Lipoxmax+40% Lipox max) for eight children.
Results:
All children exhibited a decrease in weight (LI: -5.2 kg +/- 0.7 (P<0.01), HI: -7 kg +/- 0.7 (P<0.01)). While in the LI group, both fat and CHO oxidation were unchanged after training, HI group oxidize less fat and more CHO after training when exercising at 20% and 30% Wmax th (P = 0.02).
Discussion:
While a LI exercise training program maintains (but does not improve) the ability to oxidize fat at exercise, HI training actually shifts towards CHO the balance of substrate oxidation during exercise. Thus, a low intensity training protocol seems to counteract to some extent the decline in lipid oxidation at exercise that occurs after a hypocaloric diet, and is thus likely to be synergistic to diet in the weight lowering strategy.
Related Concept Videos
Exercise and Muscle Performance
Endurance exercises
Endurance exercises involve running, swimming, or cycling, which require repetitive movements with low force output. When a person engages in endurance exercise, a few noticeable changes occur in their skeletal muscles. For instance, the number of capillaries...
Exercise and Cardiovascular Response
Light to moderate physical activity initiates a series of interconnected responses in the body. The heart rate modestly increases in anticipation of the workout, followed by widespread vasodilation as oxygen consumption by skeletal muscles increases. This results in decreased peripheral resistance, increased capillary blood flow, and accelerated...

