How hard to exercise?
Many people quit exercising within a couple of weeks after starting to exercise. Many times this is because they find exercise too hard, they exercise at the wrong exercise intensity (how hard the exercise feels). The truth is that exercise cannot be easy (overload principle) but it also has to be doable if you want to get fitter. If exercise is too easy you will not get the adaptations that you want (improved fitness, for example) that will make exercise easier in the long run.
The overload principle states that in order to adapt, the exercise stimulus has to be greater than what you are always used to. In other words, you have to provide your body with an exercise intensity (how hard you go) greater than usual.
For example, if you walk around your office and to other offices in your floor or other floors taking the elevator every day, then you are used to doing exactly that and is not challenging. Anything easier or less than that (sitting the whole day) will not provide a challenge and will not make you fitter, there is no overload. If you take the stairs to go to the other offices, that will be harder than what you do every day and will provide an overload. After providing your body with that overload several times (5 days a week, for 4 weeks, for example) you will feel that taking the stairs feels easier than at the beginning. At that point we can say that you have adapted to that initial overload and need a greater overload (progressive overload principle).
If at the beginning of that period of overload, you could take the stairs to go to only one floor up before having to take the elevator because you were to tired, that means that one flight of stairs was enough stimulus, provided an overload. On the second week, maybe you were able to take two flights of stairs, continuously or intermittent, before taking the elevator. At that point you had already adapted to one flight of stairs and it wasn't enough to continue acquiring more adaptations so you needed more (progressive overload principle).
The easiest way to know if taking 3 flights of stairs (or lifting 20 lbs, or doing 6 lunges) is enough or not, is by perceived exertion (check the next column), to check how you feel. If you feel 3 flights are too hard because you can 't do 3, then try 2 or 1. And if you are consistent, you will adapt to that and will be able to do more in the future.
This is the case for cardiovascular (aerobic) exercise, resistance (weights) exercise, calisthenics (pushups), and any other type of exercise. You need do an amount of exercise that feels harder than usual in order to give an adequate stimulus to your body and provoke an adaptation (getting fitter). Once you have that adaptation you need to keep increasing your stimulus (progression) to keep adapting and getting fitter.
Perceived exertion means how hard you feel when you are working. This is useful to gauge how hard you should be exercising. Look at the graph above and you will see that as you increase the effort, speed or number of repetitions of your exercise, keeping everything else constant, the exercise intensity or perceived effort increases, it feels harder. And when you reach maximum effort, speed, or repetitions, you need to stop because it is too hard to continue. At this point, your perceived effort is also maximal.
You hardly need to reach maximal effort to reap the benefits of increased fitness; but exercising at an intensity that is too low to give you an appropriate stimulus is also bad because you will not get adaptations from it and will waste your time, not getting fitter.
To help you keep track of your effort and intensity you can use the Borg scale. This is a scale that tells you the rate of perceived exertion or RPE. The scale starts at 6 and this means complete rest, you are doing nothing at all, not moving. Then it goes all the way to 20 which is maximum effort. When you feel that you can no longer keep exercising that means that you are at 20, because you are at your maximum, and will need to stop.
The desired range of exercise intensity using the RPE scale is between 12 and 16. Many people find 13 very comfortable. Less than 12 will give you minimal, if any, gains in fitness. More than 16 will not necessarily increase the fitness adaptations you get related to health and increases the chance of injury. They are better left for individuals interested in competitive sports.
The idea is to pick an intensity that you can sustain for the duration of the exercise or workout depending on what type of workout you are doing.
- Other ways exist to monitor your exercise intensity. Check the information about heart rate monitors.
- Learn about the progressive overload principle.