Concurrent Strength and Endurance Training

Concurrent Strength and Endurance Training: From Molecules to Man.
SYMPOSIUM

Medicine & Science in Sports & Exercise. 38(11):1965-1970, November
2006.
Nader, Gustavo A.

Abstract:
Strength and endurance training produce widely diversified
adaptations, with little overlap between them. Strength training
typically results in increases in muscle mass and muscle strength. In
contrast, endurance training induces increases in maximal oxygen
uptake and metabolic adaptations that lead to an increased exercise
capacity. In many sports, a combination of strength and endurance
training is required to improve performance, but in some situations
when strength and endurance training are performed simultaneously, a
potential interference in strength development takes place, making
such a combination seemingly incompatible.

The phenomenon of concurrent training, or simultaneously training for
strength and endurance, was first described in the scientific
literature in 1980 by Robert C. Hickson, and although work that
followed provided evidence for and against it, the interference
effect seems to hold true in specific situations. At the molecular
level, there seems to be an explanation for the interference of
strength development during concurrent training; it is now clear that
different forms of exercise induce antagonistic intracellular
signaling mechanisms that, in turn, could have a negative impact on
the muscle's adaptive response to this particular form of training.
That is, activation of AMPK by endurance exercise may inhibit
signaling to the protein-synthesis machinery by inhibiting the
activity of mTOR and its downstream targets. The purpose of this
review is to briefly describe the problem of concurrent strength and
endurance training and to examine new data highlighting potential
molecular mechanisms that may help explain the inhibition of strength
development when strength and endurance training are performed
simultaneously.