Another way to gauge the intensity of your exercise session is to rate your Perceived Exertion. All you have to do is think about how hard you're working, and use the following scale:
Borg Scale of Perceived Exertion
6 no exertion at all
7 extremely light
9 Very light
13 Somewhat hard
15 Hard (heavy)
17 Very hard
19 Extremely hard
20 Maximal exertion
BEGINNERS: Your rate of Perceived Exertion should be between 9 and 12.
INTERMEDIATE: Your rate of Perceived Exertion should be between 12 and 15.
ADVANCED: Your rate of Perceived Exertion should be between 13 and 16.
The best way to make the most of your cardio training is to monitor your heart rate and rate your perceived exertion. Try one or the other the next time you exercise. If you make an effort to think about these two things, you'll be able to see your improvement and notice a difference in both your intensity and endurance!
When we go to the gym or use our own cardio training equipment, a lot of the time we will see a program called "fat burning zone" or "fat burning workout." For many years, our perception has been that if we exercise at a lower intensity we'll "burn more fat." People think that by increasing intensity, we start to "only" burn sugars and therefore we're not burning as much fat as we could be at a lower intensity. This way of thinking is completely false. While the science behind fat-burning and sugar or carbohydrate-burning during different exercise intensities is valid, it's important to know what's really going on.
When we exercise, our bodies draw on carbohydrate, fat and sometimes even protein to give us the energy to continue. When exercising at a lower intensity, our body burns a greater proportion of fat to satisfy energy needs. As we increase intensity, the proportion of fat burned decreases and the proportion of carbohydrate burned increases. HOWEVER, don't confuse the PROPORTION of fat burned with the TOTAL AMOUNT of fat burned. As we do higher intensity exercise, we burn MORE CALORIES. As the total energy requirement increases, the total VOLUME of fat burned is greater. So, don't pay attention to the fat-burning charts on cardio training machines!
Simply, the higher the intensity of exercise, the more calories we burn. Weight management is all about calories in and calories out. When we burn more calories than we take in, weight loss occurs.
This being said, always exercise at an intensity that you can manage. Don't exert yourself to the point that you feel faint. Always drink plenty of fluids before, after and during exercise. If you're doing extremely high-intensity exercise (i.e. boot camp, long-distance running, competitive swimming, etc.) remember to fuel your body with food and water before and after. A great pre- or post-exercise snack includes protein combined with carbs or fat. (For example, chocolate milk is a great snack because it gives you carbs, protein AND fluid). Always plan ahead!