dd8f1431_How_Heart_Rate_Zones_Work__Description
[Heart Rate Zone] Zone 2 Goals: EnduranceEnergy System: Oxidative 77-85% [Description] 
This zone will also feel very easy (“conversational” effort). Training at this intensity primarily uses slow-twitch muscle fibers, since these fibers provide more most of the mobility for events lasting 2 minutes or longer, workouts at this intensity should comprise most of your training.Training above this intensity will not significantly overload your slow-twitch fibers, which you are attempting to train to become more efficient at using fat and oxygen to produce energy while conserving carbohydrate stores. If you don’t have a physically active job or aren’t able to spend lots of time on your feet during the day, this intensity is important for training the body to use fat as a fuel, especially for individuals who compete in events lasting more than two hours.Although it will be difficult to keep your intensity low on these days, if you’ve decided that you have lots of time on your hands and the type of training you want to do is primarily aerobic (vs. interval based training), then performing your endurance efforts at a higher intensity than Zone 2 will reduce the effectiveness of your harder workouts on subsequent days by fatiguing muscle and depleting carbohydrate stores in fast-twitch muscle. This can lead to overtraining and injury. In other words, if you’re going to use the “long, slow aerobic” method of training, you need to do most of it in Zone 2, not Zone 3, which is a huge mistake many endurance athletes make.
How Heart Rate Zones Work
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