You can use PulseOn during any training you make! However, the sensor measures your blood flow close to skin in your wrist and it relies on a firm sensor-skin contact during the training. Therefore, some sports like gym or racket sports, which involve strong and rapid hand movements, use of forearm muscles and movement of tendons in your wrist, may cause compromised heart rate accuracy. The sensitivity to movementcan be reduced by placing the PulseOn device higher on the forearm, about 5-8 centimeters/1,9-3,1 inches away from the bone on the side of your wrist (ulna) and also by tightening the device firmly against the skin. We continuously drive for improvements in measuring accuracy in this kind of challenging sports.