Norwegian scientists conducted two studies on experienced athletes, one on long-distance runners [1] and the other on cyclists [2]. These endurance athletes were put on a pure strength program, 4x4RM half-squats three times a week, in addition to their usual endurance training. This is real lifting, not high-rep, light-weight nonsense. Eight weeks later, the athletes not only got stronger and more explosive—without gaining any weight—they improved their sport-specific endurance. Movement became more efficient and the time to exhaustion at maximal aerobic power increased. There are several reasons strength made this happen. Here is one. The stronger the muscle, the less it has to contract to produce a given amount of force. [3] It may be obvious, but it is profound. In the above studies, the athletes increased their movement economy and decreased their perceived effort. How does our body perceive effort? The nervous system measures the intensity of the neural drive going to the muscles. [4] The muscles send back messages about the level of tension generated, the speed of movement, and the distance covered. The brain compares the intensity of the “nerve force” with the outcome and determines the degree of effort. [5] “A strong muscle requires a lower neural drive to generate a given force, because the force represents a smaller proportion of its maximum capacity. Similarly, a fatigued muscle requires a higher neural drive to generate a given force, because the force represents a higher proportion of its maximum capacity.” [6] Støren et al., 2008 Sunde et al., 2010 deVries, 1980 McCloskey et al., 1983 Cafarelli, 1982 McConnell, 2009
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