Main Body
3. Intensity
Intensity is the amount of work required during exercise and the rate at which energy (ATP) is used. Several factors go into intensity including the weight being lifted, the amount of sets and reps performed, and the time in between sets. Anything to make an exercise more or less challenging is a matter of changing intensity.
Monitoring Intensity
1. Heart Rate Monitor
The most practical and easiest way to monitor intensity is with a heart rate monitor. If you own a heart rate monitor, completing a few simple equations prior to coming to class will make it easy to track your intensity. Typically, it is recommended to exercise in a range between 65%-85% of your estimated maximum heart rate (MHR).
To calculate your estimated maximum heart rate (MHR), you subtract your age from 220: (MHR=220-age). See the example below.
Ex: 20 year-old cyclist
220-20 = 200
200 = Estimated MHR
200 x (.65) = 130 beats per minute (BPM)
200 x (.85) = 170 BPM
A 20-year-old cyclist would want to keep a heart rate between 130-170 BPM depending on the desired level of intensity. It is important to remember this is just an estimate of your true heart rate maximum; therefore, it is not 100% accurate. The downside to utilizing this method to measure exercise intensity is not everyone has the money to purchase a heart rate monitor and when you are exercising on a bike, it is difficult to stop and take your pulse. Therefore, we’re going to explore a few other methods for measuring intensity.
2. Borg’s Rate of Perceived Exertion (RPE)
Another way to measure intensity is with Borg’s Rate of Perceived Exertion scale. Perceived exertion is based on how intense the exercise feels at any given moment. The Borg Scale measures intensity based on perceived feelings of fatigue. It is a scale that ranges from 6-20 with 6 being very, very easy, and 20 being extremely difficult. The problem with this scale is that it is difficult for users to know and determine the difference between the numbers. For example: what is the difference between a rating of an 8 and 9? How different will a rating of 9 feel from a 10? Additionally, 6-20 is a big range and often seems confusing to participants in an exercise class.
3. Talk Test
A simplistic way to track your intensity during a workout is to use the talk test. During most of your training, you should be able to talk with your neighbor. If you are training by yourself, you can try reciting the pledge of allegiance. If you cannot talk in complete sentences during your training, slow down! You can also insert planned breaks during your workout. Keeping your intensity manageable will allow you to accumulate more training time and will slowly strengthen your muscles, bones, and tendons (rather than breaking them down) so you are prepared for faster training later. Sometimes you will want to train harder and will not be able to talk so easily.
4. Percentage of Race Pace
If you have run a recent time trial or a previous race (such as a 5k), you can use percentages of your race pace to assign intensity for subsequent training. You can measure your speed in minutes per mile using GPS watches, online mapping tools (www.mapmyrun.com), or measured tracks and running trails.