Sensory pleasure optimizes muscular work.

Purpose: To determine how an individual optimizes muscular work.

Source: Several previous investigations by the author that explored the hedonicity of various sensations aroused during work and compared the results with the subjects' performances.

Principal Findings: When a subject is given the task to climb 300 m elevation on a treadmill, at various combinations of speed and slope, if slope is imposed and speed self adjusted, or speed imposed and slope self adjusted, the subject spontaneously climbs the 300 m in a constant time. Thus, the subject worked his body at a constant power (work x duration(-1)). Thus, a person optimizes his own behaviour spontaneously. Systematic exploration of the hedonic dimension (pleasure/displeasure) of sensory experience from various parts of the body, over a broad range of muscular work showed that pleasure is experienced when a useful stimulus, as judged from the point of view of optimization of physiological function, is present. Displeasure occurs when a noxious stimulus is present. When a stimulus is neither useful nor noxious, the sensation aroused is indifferent. The relationship of hedonicity with physiology is so tight that these properties of sensation can be used as a tool to explore the body's physiological integrity. Hedonicity is also aroused during muscular exercise. Experimental evidence will be provided to demonstrate that the pleasures/displeasures of sensory inputs from the chest and from muscles are the signals that are the source of optimal muscular work.

Conclusion: The experimental results confirmed that pleasure is the common currency that is used by the brain to compare sensations aroused by muscular work from various parts of the body. Maximization of the algeabraic sum of these hedonic sensations optimizes the resulting muscular performance.