A training garment (10) for developing an athlete's inspiratory muscles, comprises a resistance band (12) and adjustment means (13). The resistance band (12) is configured such that when the training garment (10) is in use during the performance of aerobic exercise, the resistance band (12) embraces the athlete's thorax and imparts a resistive load thereto. The adjustment means (13) enable the athlete to vary the applied resistive load. The training garment (10) resists the expansion of the athlete's thorax during the performance of aerobic exercise, but without restricting the athlete's range of motion.