Barry S. Braun, associate professor of kinesiology and director of the Energy Metabolism laboratory at UMass Amherst, says most people who exercise aren’t competitive athletes. They exercise to help their overall health, seeking to manage their weight and reduce risk for diabetes, heart disease or other health problems. For them, the potent benefits of exercise are quickly reversed by consuming high-carbohydrate foods such as sports drinks and energy bars after workouts.
Braun says for ordinary people who are using physical activity to improve their health, exercise is a medicine. Each “dose” of exercise gives benefits but the effects are lost in one to two days. Like other medications, exercise also has interactions with food. Recommendations for athletes seeking to optimize their performance may be precisely the wrong advice for people using exercise to improve their health. The latter might be wiser to avoid sports drinks and energy bars during, and for one to three hours following, exercise to maximize the positive effects of each exercise “dose,” Braun says.
In three recently published studies, graduate students under Braun’s direction looked at how the total calories, the carbohydrate content, and the timing of post-exercise meals influence metabolic health. In the first study, published in the Journal of Applied Physiology, Steve Black showed that walking on a treadmill for one hour daily, which burned 500 calories, increased the effectiveness of insulin to clear blood sugar by 40 percent. But when the 500 calories burned was replaced by feeding the participants a high-carbohydrate drink following exercise, the positive effect disappeared entirely, along with improvements in several other key health markers like blood lipids and inflammatory proteins.
To understand whether the negative effects of the post-exercise meal were due to the total calories or to the carbohydrate content of the meal, Kaila Holtz tested two different meals given immediately after 75 minutes of moderately intense bicycle exercise. The meals contained exactly the same amount of calories but one was high in carbohydrates and the other was very low in carbohydrates. Her results, published in the Journal of Applied Physiology, Nutrition and Metabolism, showed that the effectiveness of insulin to clear sugar from the blood was greater after either exercise/meal combination compared to participants who did not exercise. The effects were larger, however, when the meal was low in carbohydrates. These results suggest that, when the post-exercise meal is low in carbohydrates, more of the metabolic benefits of exercise are retained.
Brooke Stephens-Hasson conducted a study, also published in the Journal of Applied Physiology, Nutrition and Metabolism, in which she changed the timing of when the meal was given while keeping the total calories and carbohydrate content of each meal constant. She compared identical meals given before, immediately after, or three hours after 75 minutes of moderately intense bicycling. Once again, the effectiveness of insulin to clear blood sugar was better after any of the exercise conditions compared to a no-exercise condition. Although there were a few subtle differences, the results were similar among all three exercise/meal combinations, suggesting that timing of the meals was not an important consideration.
Barry S. Braun | Newswise Science News
The Great Unknown: Risk-Taking Behavior in Adolescents
19.01.2017 | Max-Planck-Institut für Bildungsforschung
A sudden drop in outdoor temperature increases the risk of respiratory infections
11.01.2017 | University of Gothenburg
For the first time ever, a cloud of ultra-cold atoms has been successfully created in space on board of a sounding rocket. The MAIUS mission demonstrates that quantum optical sensors can be operated even in harsh environments like space – a prerequi-site for finding answers to the most challenging questions of fundamental physics and an important innovation driver for everyday applications.
According to Albert Einstein's Equivalence Principle, all bodies are accelerated at the same rate by the Earth's gravity, regardless of their properties. This...
An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...
Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...
Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.
While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...
Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales
Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...
19.01.2017 | Event News
10.01.2017 | Event News
09.01.2017 | Event News
23.01.2017 | Health and Medicine
23.01.2017 | Physics and Astronomy
23.01.2017 | Process Engineering