Our bodies deliver energy to the muscular system in a number of important ways. The science which concerns itself with the various ways in which our body receives energy is known as energy metabolism. Now, the degree to which your body “chooses” its energy source is dependent on the type and intensity of exercise you are engaged in.
If we take for granted that measuring intensity in training is necessary, it becomes important to choose a method of measurement that fits your needs. (BLOG- Measuring intensity in swimming)
All too often, we meet swimmers and triathletes who swim a specific distance as fast as they can at every training session. Approaching your training in this way is a sure path to finding your performance plateaued. Varying your training throughout the aerobic ranges, and yes even anaerobic range, is the only way to sustain long term improvement in your aerobic capacity.
For sustainable growth, training must be carefully planned and executed. Thus, we need a system for measuring training intensity. Available systems vary in their ease of use and accuracy. We have the Aussie System, The “Color” system, lactate testing, rate of perceived exertion… the list goes on.
For beginning training planners I might suggest the simple “Gear system”. Varying your training through the aerobic ranges with touches of anaerobic work will be a great place to start.
| Gear | Training Zone | Corresponding Heart Rate |
| 1 (Smooth) | Low Aerobic |
50 Beats Below Max |
| 2 (Mid Aerobic) | Mid Aerobic | 40 Beats Below Max |
| 3 (Hard Aerobic) | High Aerobic/ Threshold | 30 Beats Below Max |
| 4 (Sub Max) | Anaerobic VO2 Max | 20 Beats Below Max |
| 5 (Full Max) | Anaerobic Overload | 10 Beats Below Max |