While jogging, cycling, swimming, and other forms of cardio exercise are well-known ways to burn calories, the relationship between strength training and weight loss is more complex. A new study has dug into the molecular foundations of this and identified a new mechanism by which muscle cells provide instructions that send fat cells into fat burning mode in response to a mechanical load.
For hundreds of years, humans have used different forms of resistance training to improve muscle strength and size. In gyms today, this could involve machines, free weights, or resistance bands, which damage all of the muscle fibers that the body then repairs by fusing them together to increase their mass.
Resistance training in its many forms has also started to gain popularity among those looking to shed extra pounds or protect themselves against obesity. While shedding iron is unlikely to burn as many calories as a vigorous session on a stationary bike, it may have side benefits for long-term weight management.
In addition to strengthening and building muscle, resistance training has an ‘after burn’ effect in which oxygen uptake remains high to help break down fats and carbohydrates to replenish tired muscles, well. after the end of training. Increased muscle mass can also increase the body’s resting metabolic rate, which dictates the number of calories the body needs to function while at rest, thus improving long-term fat burning.
Scientists at the University of Kentucky sought to build on this growing body of evidence on the unique ways that resistance training can help with weight management, by digging directly into physiological details. It started with studies on mice, through which scientists showed that a mechanical overload of muscles, simulating the effects of resistance training, led to the release of so-called extracellular vesicles, which are particles that cells naturally expel to help rid the body. protein, fat and other unwanted material.
Recent studies have started to show that extracellular vesicles also act as a sort of messenger, relaying communications between different types of cells. And this is the process that turned out to be at play in muscle mice, with the vesicles released during resistance training being preferentially absorbed by white fat cells, and in turn given them instructions to switch to fat burning mode.
“To our knowledge, this is the first demonstration of how strength training initiates metabolic adaptations in fatty tissue, which is crucial in determining whole-body metabolic results,” says John McCarthy, author of The study. “The ability of resistance exercise-induced extracellular vesicles to improve fat metabolism has important clinical implications.”
Through follow-up experiments in human tissue, the scientists discovered that similar signaling processes were at play, which led them to suspect that the same effects of resistance training “may be operational in humans. “.
In addition to deepening our understanding of how resistance training can help our waistlines, the researchers say the study also sheds light on how extracellular vesicles can facilitate communication between different tissues in the body. .
The study was published in the FASEB review.
Source: University of Kentucky