In a study that involved horses, mice and humans Researchers discovered clues to which kinds of exercise reduce appetite and the reasons for this.

What is it that makes us feel hungry after workouts, but not interested in eating after other meals?

In a study that was released on the Wednesday of Nature, a multidisciplinary team of researchers suggest that the solution is in part in the actions of one chemical that is produced following exercise and blocks the appetite. The molecule — which was found throughout the bloodstreams and tissues of mouse racehorses, and humans and racehorses — was found in greater numbers after intense exercise than in easy one, suggesting working out is a crucial factor in regulating the amount of food we consume afterward.

The connection between exercise and food is well-known as a thorny one. Studies have proven that people who begin exercising without controlling their intake of calories tend to lose only a few pounds over time. However, they might gain weight. A variety of factors can influence the outcome, such as present fitness level weight, body mass as well as diet and gender, genetics, metabolic rate and even time of exercise. Certain research studies, though not all of them suggest that exercise in the morning can be more effective in burning fat than similar exercises later in the day.

Food intake is also a factor. If you’re feeling hungry during the days following a workout it is possible to end eating more calories than you burn. What causes us to feel hungry , or not after exercising remains an unanswered question. For decades, researchers have been able to identify various substances that, such as leptin and ghrelin connect to the brain to cause us to become more or less hungry.

Studies have shown that exercise alters the concentrations of these chemicals however, so does the way you eat and your sleeping habits. Researchers began to think whether there could be any kind of reaction specific to exercise that affects appetite.

Researchers at Stanford University School of Medicine, Baylor University, the University of Copenhagen and other institutions utilized new methods to search for molecules that appear more frequently in bloodstreams after exercising. They started with mice and set them up on treadmills that were tiny and able to sprint at a higher speed until they exhausted. They collected blood prior to and following the run and then compared the concentrations in thousands of molecules present in the blood of rodents.

One stood out, growing significantly more than other molecular. It was previously reported in a couple of studies of fitness and metabolism, but its biological and chemical properties was not fully understood. Researchers discovered that this moleculecomposed of lactate and amino acid phenylalanine was apparently created due to the elevated levels of lactate that are released during exercising. The researchers named it lac-phe.

Researchers speculated lacphe could be involved in the energy balance following exercise as the cells in the blood, and in other places that make it are involved in consumption of calories as well as body weight. They speculated that it can affect appetite. To determine this the answer, they fed a type of lac-phe (lac-phe) to obese mice, who normally eat with a frenzied. However, their consumption of kibble dropped nearly 30 percent. They seemed to be less hungry because of the added lac-phe.

The researchers then switched back to physical exercise. They developed mice that did not produce any lac-phe, and then had them run for hours on treadmills 5 times per week for a period of several weeks. After every run, the animals were given as much high-fat food as they desired. Usually, running can help mice stop weight gain even when eating a diet high in calories. However, the mice are unable to create a large amount of lac-phe, they ended up taking in more kibbles and gaining around 25 % more pounds than group that was controlled.

Lac-phe was a major factor in how exercise can help mice stay away from weight increase. Without it, the same exercise could have led to overeating.

In the end, researchers looked for lac-phe levels in other exercise animals. The first time they found it was within the racehorse’s bloodstream, which were at greater levels after an intense run than they did before. They then requested eight healthy men to do three workouts for three times: one time by cycling in a relaxed manner over 90 minutes a second time with weights, and the third time doing a series of 30-second sprints while riding the stationary bike. Lac-phe levels in blood spiked following each exercise, but were the highest following sprints, which were followed by the weight-training. The long, gentle workout resulted in the lowest level of lac-phe.

The more vigorous the exercise, more lac-phe produced in mice, at the very least the more appetite was observed to decrease.

“The results are intriguing and provide a fresh dimension to our ideas about exercising and body-weight regulation.” stated Richard Palmiter, a professor of biochemistry at the University of Washington in Seattle and an expert on the neurobiology of behavior, who was not part of the latest study.

“We always believed that our current set of molecule that appears to regulate appetite and consumption, including leptin, Ghrelin, etc. is not comprehensive which is why this potential metabolite or signaling molecular is likely to be a significant supplement to the existing number,” said Barry Braun who is the director of the executive office of the Human Performance Clinical Research Lab at Colorado State University in Fort Collins who is a specialist in exercises and weight control. He wasn’t involved in the study.

Assuming that this process works similarly in humans and in mice and rats, the discovery of lacphe offers an interesting information. If we are looking to prevent the habit of binge eating inafter training and avoid binge eating, it may be necessary to intensify our workout according to Jonathan Z. Long Professor of pathology at the Stanford University School of Medicine and the lead researcher on the study.

This concept makes intuitive and natural sense in the evolutionary perspective, he said. “If you’re running away from a rhino or other danger, your autonomic nervous system shouts into the mind to stop down digestion and other unnecessary processes.”

The study isn’t able to provide any information about what the mechanism by which lac-phe interacts with brain cells in order to regulate appetite or how vigorous exercise has to be in order to trigger lac-phe production or how long the effects of the molecule may last. Additionally, the exercisers were healthy males, which means we don’t know if lac-phe is present or functions similarly to all other.

If you’d like to feel less hungry after exercise You might want to increase your pace. Include some hills in your next walk , or run towards the corner of the street. “What research suggests is that intensity is a factor” in the context of fitness and control of appetite Dr. Long said.