New apparatus for exercising a monkey seated in a primate chair.

A new apparatus and method for exercising a monkey seated in a primate chair are described. The apparatus consists of a set of hand and foot bars mounted at either end of a rocker arm that pivots in a vertical plane. This arm is connected by a steel cable to a wooden box that houses lead weights. By simultaneously pushing the foot bar and pulling the hand bar, the monkey lifts a weight and triggers a microswitch which releases a banana-flavored food pellet into a well close to the animal's mouth. The amount of work performed is varied by changing the a) amount of weight to be lifted, b) distance the weight must be lifted, or c) number of times that the animal lifts the weight for a single reward. During 30 min of exercise, the heart rate of a given monkey rose 120 beats/min, respiratory rate 24/min, and colonic temperature 1.2 degrees C above base-line values. Total work performed in 30 min varied from 250 to 360 kpm. Major advantages of this apparatus over a treadmill or bicycle ergometer are that the animal 1) is restrained sufficiently to permit the delicate experimental manipulations and physiological measurements, 2) can be exercised strenuously in a quantitative fashion, and 3) is readily trained to perform the task in a short time.