During exercise and physical activity, the primary fuels used by muscles are carbohydrate and fat. When mild exercise is performed there is a tendency to burn relatively more fat and less glucose, but as exercise becomes more intense, a higher fraction of the energy demands of the muscle are supplied by glucose, until at the highest intensities almost only carbohydrates are used. Is this shift in fuel source a property of the muscle itself, or does it represent the interplay between what is happening in the muscle and the exercise-related responses in the rest of the body?
The study, performed at the Copenhagen Muscle Research Centre at the University of Copenhagen, examined muscle fuel utilisation in response to graded exercise performed with only one leg. Nine healthy males performed one-leg exercise at 25, 45, and 85% of maximal workload. Their results showed that, when only a small mass of muscle is contracting, and blood flow and oxygen supply are not limited by central circulatory capacity, the shift in fuel source from fat to glucose as exercise intensity increases does not occur.
Helge et al.’s findings show that the adaptations in the rest of the body are the key to this fuel source shift during whole body exercise. They also help scientists understand why athletes "hit the wall" during events like the marathon, and they have implications for the adaptations made in middle-aged adults who are using exercise to prevent or treat conditions like diabetes and obesity. If the mechanisms can be fully understood, it may be possible to develop agents that allow fat oxidation to be maintained even during intense exercise with a large muscle mass.
Antibiotic effective against drug-resistant bacteria in pediatric skin infections
17.02.2017 | University of California - San Diego
Tiny magnetic implant offers new drug delivery method
14.02.2017 | University of British Columbia
In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport
Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...
The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.
The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...
Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...
Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".
Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...
13.02.2017 | Event News
10.02.2017 | Event News
09.02.2017 | Event News
17.02.2017 | Medical Engineering
17.02.2017 | Medical Engineering
17.02.2017 | Health and Medicine