When you work out, you burn calories. Some come from fat, some from other sources (digestion and stored reserves).
The lower your heart rate, the more that comes from fat (burning fat is slow).
The higher the heart rate, the more that comes from other sources of quicker energy.
At high heart rates fat burning and digestion stop and you only burn quick energy stores.
By maintain low heart rates, you burn a higher percentage of fat. The cost is you burn it much slower. So the time spent exercising goes up.
Given that Cannon has joint problems and if he has the time, and his goal is to lose fat... a long, low intensity work out with a proper diet (ie not too many calories coming in) would max the fat burn.
Heart Rate Training Zones Heart
Heart rate training zones are calculated by taking into consideration your Maximum Heart Rate (MHR) and your Resting Heart Rate (RHR). Within each training zone, subtle physiological effects take place to enhance your fitness.
The Energy Efficient or Recovery Zone - 60% to 70%
Training within this zone develops basic endurance and aerobic capacity. All easy recovery running should be completed at a maximum of 70%. Another advantage to running in this zone is that while you are happily fat burning you may lose weight and you will be allowing your muscles to re-energise with glycogen, which has been expended during those faster paced workouts.
The Aerobic Zone - 70% to 80%
Training in this zone will develop your cardiovascular system. The body's ability to transport oxygen to, and carbon dioxide away from, the working muscles can be developed and improved. As you become fitter and stronger from training in this zone it will be possible to run some of your long weekend runs at up to 75%, so getting the benefits of some fat burning and improved aerobic capacity.
The Anaerobic Zone - 80% to 90%
Training in this zone will develop your lactic acid system. In this zone, your individual anaerobic threshold (AT) is found - sometimes referred to the point of deflection (POD). During these heart rates, the amount of fat being utilised as the main source of energy is greatly reduced and glycogen stored in the muscle is predominantly used. One of the by-products of burning this glycogen is lactic acid. There is a point at which the body can no longer remove the lactic acid from the working muscles quickly enough. This is your anaerobic threshold (AT). Through the correct training, it is possible to delay the AT by being able to increase your ability to deal with the lactic acid for a longer period of time or by pushing the AT higher.
The Red Line Zone 90% to 100%
Training in this zone will only be possible for short periods. It effectively trains your fast twitch muscle fibres and helps to develop speed. This zone is reserved for interval running and only the very fit are able to train effectively within this zone.
http://www.brianmac.co.uk/hrm1.htmIn my research and opinion, and if Cannon has the time... Train a huge amount of time in the low threshold area (fast but comfortable walking). Occasionally train in the high thresholds for short periods of time just to be able to make times for timed events during testing. These intense workouts are largely for the cardiovascular system so they do not even have to be running. It can be biking or any other activity that can get the heart rate up for 15 to 20 minutes to high levels without stressing the joints.
