Polar USA

TARGET ZONE	INTENSITY % OF HRmax	EXAMPLE DURATIONS	PHYSIOLOGICAL BENEFIT/TRAINING EFFECT

5 - Maximum	90-100%	Less than 5 minutes	Benefits: Increases maximum sprint race speed Feels like: Very exhausting for breathing and muscles


4 - Hard	80-90%	2 - 10 minutes	Benefits: Increases maximum performance capacity Feels like: Muscular fatigue and heavy breathing


3 - Moderate	70-80%	10 - 40 minutes	Benefits: Improves aerobic fitness Feels like: Light muscular fatigue, easy breathing, moderate sweating


2 - Light	60-70%	40 - 80 minutes	Benefits: Improves endurance, helps recovery Feels like: Comfortable, easy breathing, light sweating


1 - Very Light	50-60%	20 - 40 minutes	Benefits: Improves overall health and metabolism Feels like: Very easy for all bodily functions