I recently looked into target heart rates and wrote about calculating your maximum heart rate and your target rate, which is the range where you get the most benefit from your exercise.
Once you know your maximum heart rate (220 minus your age), you should begin to track your heart rate by manually taking your pulse during exercise or with a heart-rate monitor.
From there, you can determine which zone you should exercise in.
Surprise! There are lots of differing opinions on what heart rate range you should exercise in. Depending on whom you ask, there are three to five zones and many different opinions on what percentage of time you should spend exercising within each one. Yet, there are some common conclusions that you can focus on. Chief among them is, slow down! You’ll get the most physical benefit with the least risk.
First, though, let’s use a five-zone model. (See http://www.thewalkingsite.com/thr.html)
Zone 1: Warm up. (50% to 60% of your maximum heart rate.) While this is a warm-up zone for many, it’s a great place for people just starting an exercise program. While it may not sound macho, you get nearly all exercise benefits here with very little risk to your body. Here’s where 85% of calories burned are fats. Cholesterol is reduced and blood pressure is decreased.
Zone 2: General Fitness. (60% to 70% of your maximum heart rate.) The benefits are the same as zone one, but more total calories are burned.
Zone 3: Endurance Zone. (70% to 80% of your maximum heart rate.) If you’re training for an endurance event, this is your zone. It strengthens and improves your cardiovascular and respiratory systems and increases the strength of your heart. More total calories are burned; 50% of them are from fat.
Zone 4: Performance Training. (80% to 90% of your maximum heart rate.) This high intensity zone improves the amount of oxygen your body can absorb. Only 15% of calories you burn here are from fat.
Zone 5: Maximum Zone. (90% to 100% of your maximum heart rate.) Most people stay in this zone for only short periods of time, and only athletes in very good physical shape should train here.
Nearly all exercise professionals recommend that you spend most of your time in zones under 80%. The benefits are the greatest here, and the risks are at their lowest. For serious athletes, there are differing opinions on how much time you should spend in higher zones.
In More magazine (http://www.more.com/how-to-exercise-heart-rate-zones) Stephen Seiler, Ph.D, a sports-science professor at the University of Adger in Norway, suggests spending 80% of your exercise time below 80% of your maximum heart rate, and 20% at above 90%. He says that the 80% to 90% of maximum heart rate where most exercises do most of their cardio work is a “black hole” because you’re not exerting the type of effort that builds lungs and heart while your body is producing by-products that lead more to muscular fatigue.