When muscles contract they use energy that is derived from food. It is a two-step process. The first step occurs in mitochondria, where the energy from molecules like glucose or fats is locked away in ATP (adenosine triphosphate). This ATP travels from the mitochondria to sites in the muscle where energy is needed, and the energy is released and used. At both of these stages there is the possibility for energy to be lost, causing a reduction in efficiency. The proportion of food energy that ends up making the muscles move is a measure of the efficiency of the system, and this is known to vary considerably between people.
The main theory is that this variation comes from differences in the efficiency with which mitochondria convert food energy to ATP. But results published in this fortnight’s edition of The Journal of Physiology indicate that any differences in the efficiency of individual mitochondria cannot explain the differences in overall efficiency between people. Consequently these differences must lie in the way the ATP is used within the muscle.
The research was carried out on healthy human volunteers by a team of scientists working at the University of Southern Denmark, Odense, and the Karolinska Institute/GIH, in Stockholm, Sweden. It combined exercise testing of individuals, with laboratory analysis of muscle samples.
The results showed that work efficiency was correlated with muscle fibre type composition and with the amount of UCP3 protein – muscles with high proportions of this protein had lower efficiencies than those with low proportions.
“It’s too early to say whether UCP3 causes this difference, or whether it is a marker of some other process, but further research might someday lead to training strategies that will help us improve efficiency, or identify subjects who have the potential to become more efficient over time,” says lead author Martin Mogensen.
“The work is an excellent example of integrative physiology, addressing questions both at the sub-cellular and whole body levels that have implications for basic muscle energetics as well as athletic performance,” says Professor Edward Coyle, of the University of Texas at Austin, in an accompanying editorial.
Lucy Mansfield | alfa
Nanoparticle Exposure Can Awaken Dormant Viruses in the Lungs
16.01.2017 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt
Cholera bacteria infect more effectively with a simple twist of shape
13.01.2017 | Princeton University
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...
Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.
As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...
At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).
Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...
Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.
The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...
10.01.2017 | Event News
09.01.2017 | Event News
05.01.2017 | Event News
17.01.2017 | Earth Sciences
17.01.2017 | Materials Sciences
17.01.2017 | Architecture and Construction