There’s an interesting study which looked at two months of training at FATmax to see what the effects on Metabolic Syndrome (Dumortier M, Brandou F, Perez-Martin A, Fedou C, Mercier J, Brun JF. Low intensity endurance exercise targeted for lipid oxidation improves body composition and insulin sensitivity in patients with the metabolic syndrome. Diabetes Metab. 2003 Nov;29(5):509-18). The study showed good improvements from MAF level of training intensity.
The patients exhibited a significant reduction in body weight (- 2.6 +/- 0.7 kg; P=0.002), fat mass (- 1.55 +/- 0.5 kg; P=0.009), waist (- 3.53 +/- 1.3 cm; P<0.05) and hip (- 2.21 +/- 0.9 cm; P<0.05) circumferences, and improved the ability to oxidize lipids at exercise (crossover point: + 31.7 +/- 5.8 W; P<0.0001; LIPOX(max): + 23.5 +/- 5.6 W; P<0.0001; lipid oxidation: + 68.5 +/- 15.4 mg.min(-1); P=0.0001). No clear improvement in either lipid parameters or fibrinogen were observed.
There were significant improvements in the markers of Metabolic Syndrome.
The surrogates of insulin sensitivity evidenced a decrease in insulin resistance: HOMA%S (software): + 72.93 +/- 32.64; p<0.05; HOMA-IR (simplified formula): – 2.42 +/- 1.07; P<0.05; QUICKI: + 0.02 +/- 0.004; P<0.01; SI=40/I: + 3.28 +/- 1.5; P<0.05. Significant correlations were found between changes in body weight and HOMA-IR and between changes in LIPOX(max) and QUICKI.
Here’s a longer term study which shows positive results over a longer time period (Drapier E (2018) Long term (3 years) weight loss after low intensity endurance training targeted at the level of maximal muscular lipid oxidation. Integr Obesity Diabetes 4).
Average weight loss was -2.95 ± 0.37 kg after 3 months, -4.56 ± 0.68 kg after 1 year, -5.31 ± 1.26 kg at 2 years and -8.49 ± 2.39 kg at 3 years.
The beauty of this study was that it compared low intensity exercise to a low fat diet.
This study shows that this low intensity exercise training maintains its weight-reducing effect 3 years while diet is no longer efficient, and that this effect is initially related to muscular ability to oxidize lipids but that metabolic and behavioral adaptations have been further developed and contribute to a long lasting effect.
The results are powerful.
Here’s a third related study (J. O. Holloszy and E. F. Coyle. Adaptations of skeletal muscle to endurance exercise and their metabolic consequences. Journal of Applied Physiology 1984 56:4, 831-838).
The major metabolic consequences of the adaptations of muscle to endurance exercise are a slower utilization of muscle glycogen and blood glucose, a greater reliance on fat oxidation, and less lactate production during exercise of a given intensity.
These adaptations play an important role in the large increase in the ability to perform prolonged strenuous exercise that occurs in response to endurance exercise training.
From the results:
…Probably the most important of these is an increase in mitochondria with an increase in respiratory capacity. One consequence of the adaptations induced in muscle by endurance exercise is that the same work rate requires a smaller percentage of the muscles’ maximum respiratory capacity and therefore results in less disturbance in homeostasis.
A second consequence is increased utilization of fat, with a proportional decrease in carbohydrate utilization, during submaximal exercise.