Study Shows How Strength Training Blocks ‘Muscle Endurance’
A new study shows how strength training has a negative effect on endurance muscle fiber numbers.
The study focuses on the neurotransmitter brain-derived neurotrophic factor (BDNF) which is produced by muscle and acts on both muscles and synapses.
The results provide new insights into age-related muscle atrophy.
Prof. Christoph Handschin’s research group at the Biozentrum, University of Basel, has argued that the different impact of working out on strength and endurance muscle depends on the type of fibers they are made of.
Slow-twitch fibers influence endurance muscles, which are formed mainly during endurance sports.
However, fast-twitch fibers influence ‘strength muscles’ which gain in volume during strength training and provide particularly great muscular power.
Handschin said: “It is interesting that BDNF is produced by the muscle itself and not only exerts an influence on the muscle, it also affects the neuromuscular synapses, which the junctions between the motor neurons and muscle are.”
This remodeling of the neuromuscular synapses during strength training results in the body developing more strength muscle fibers.
“However,’ Handschin added “…strength muscle growth occurs at the expense of the endurance fibers.
“[Or] more precisely, through the release of BDNF, the endurance muscles are transformed into strength muscles.”
The new research provides a possible explanation for the decrease in endurance musculature seen as a result of strength training.
This correlation is already being taken into account in the training plan for high-performance sports.
This is particularly true in sporting disciplines such as rowing, which are geared towards strength and endurance.