›Heart Rate Training Zones

Based on zones as defined by Joe Friel

›Zone 1
Recovery Zone. Keep your HR below this number during recovery session and the intensity will be low. More experienced athletes may recover better by doing these easy workouts while less experienced athletes will recover better with total rest.

›Zone 2
Extensive Endurance. For most endurance athletes this is where the bulk of training will take place. Lactate production is quite low and the pace is conversational. This is the zone for most of your long rides and runs where you're building endurance by increasing your body's efficiency in using oxygen for energy, teaching your body to
utilize fat stores for energy and conserving glycogen and glucose. The lower end of this zone should be "easy" pace while the upper end might be considered "steady" effort that requires just a bit of concentration to hold for long periods of time.

Athletes who are endurance limited, especially those just taking on half iron and iron distance racing, should do nearly all of their training here. Beside building a big base to draw in over the course of 5-15 hours of exercise, training for long periods in Zone 2 will teach important concentration skills needed for ultra endurance events and will teach the "two p's" key to endurance race strategy: patience and pacing.

›Zone 3
Intensive Endurance. Also called "no man's land." We generally only train here during very specific workouts such as muscular endurance on the bike for experienced Ironman and Half Ironman athletes.

›Zone 4 & 5a
Threshold. Zone 4 is a bit below LT and Zone 5 a equal to or a bit above. Very beneficial for short course athletes who have developed a good base. Training just on either side of LT will improve lactate clearance ability dramatically and these types of workouts top off fitness. Use this type of workout sparingly as they can lead to injury, illness and overtraining if you go to the well too often. For ironman athletes only those elites with a good bit of experience who have gotten past the endurance and muscular endurance limiters need to train here.

›Zone 5b
Anaerobic Endurance. Intensity is high and duration of work at this level is short because the body can not clear lactate from the muscles. Lactate clearance can be improved but athletes should be careful to recovery well between sets and after these types of workouts.

›Zone 5c
Power. Bouts of exercise here are very, very, short in duration—seconds. Effort is maximal and used to build muscle mass and recruit fast-twitch muscle fibers. Training here is of very limited value to most endurance athletes and recovery times after these workouts are measured in days.