PLEASE NOTE: We are undergoing a name change. Unleashed Training is now Sprint Ninja. We still offer high quality strength and conditioning along with personal training, with our specialty being sprint training.
High intensity interval training versus long, slow cardiovascular training is an argument that has been underway for many years. So as a fitness professional and someone with experience helping athletes cut massive amounts of fat in a short time, I will provide some reliable information to this argument.
The Low-down on Energy Systems In Fat Loss
Energy systems are the centre of metabolism. No matter what physical activity you do you are using energy. The intensity of the activity is what determines the type of energy and how it is metabolised. Slow and long exercise and you will use predominantly fat that is oxidised and broken down to glucose and then into ATP where it is used for low intensity, sustained activity. Super high intensity intervals utilise glucose and/or creatine phosphate, which is then broken down into ATP to support short duration, almost maximal effort.
This is where the myth comes from that long, slow cardiovascular training burns more calories of fat and results in greater weight loss. Well they are right to a degree. Fat is the primary energy substrate used during long distance exercise. However, total energy burned is more during the short, high-intensity intervals.
All types of training need to burn something, the harder the effort, the more energy is required. Makes sense. What has created this argument is that slow and continuous effort takes a larger percentage of its energy from fat stores. So in the limited thinking used to rationalise this fact has led to a belief that this sort of exercise is optimal. However, it’s not the whole story.
When you perform high intensity exercise over short, repeat intervals, you burn a lot more calories. These are calories that if not used would end up becoming fat eventually. So your fat is then available as the primary energy source to sustain simple, low intensity tasks in daily life.
When you exercise at high intensity you go into debt. This debt needs to be repaid in order for your body to be ready to perform more of this sort of effort. If it wasn’t then you would simply wear out and die due to lack of energy. This is true for all activity, even low intensity creates debt.
So the difference here is this: During low intensity exercise you can sustain it for a long time. This means that the energy is replaced continuously within the muscle cell so that you can continue almost indefinitely. It makes sense then that this debt is not so hard for the body to repay so it doesn’t take up a lot of resources after the exercise has ceased.
High intensity on the other hand cannot be sustained. Once you perform a maximal effort the body has no choice but to slow down or stop. It is then some time before you can repeat activity of the same intensity. This results in over 24 hours of debt repayment in the form of EPOC (Excess Post-Exercise Oxygen Consumption). In order to repay this debt your body needs to call on the predominant energy system used to replace the energy and at the same time sustain basal functioning.
Translated this means that although a larger percentage of calories from fat is burned from aerobic effort, the overall calories are less. High intensity interval training utilises more total calories, even if a lot of them come from carbohydrate sources such as glucose and glycogen. For some time after the effort the body needs to recover in order to prepare for the possibility of more of this sort of effort. This requires hours or even days of burning energy. This comes from all sources including carbohydrates and fat.
Studies have now shown that high intensity interval training results in much greater losses in body fat than slow aerobic exercise.
Aug 31, 15 12:20 AM
Sprint Ninja is a fitness and physical performance business utilising an effective set of systems and training principles, specialising in sprinting performance...
Aug 30, 15 06:29 AM
Welcome to the sport and athletic conditioning articles section. Here you will find articles pertaining to specific sports and athletic events....
Aug 30, 15 06:24 AM
Being competitive is often seen as a negative thing. No doubt you have heard that you shouldn’t compare yourself to others, just do it for yourself....
YOUR COACH – Chris Lyons
Chris Lyons is an experienced strength and conditioning coach, having trained athletes of all ages and levels since 2002. Chris specialises in coaching athletes for speed and power specific to fast-moving sports such as rugby league, rugby union, soccer, Aussie rules football etc. Since 2002 Chris has conducted close to 15,000 hours of training and coaching directly with athletes and members of the general population. From this experience comes Sprint Ninja, based on tried and tested training methods combined with up to date research. Chris continues to challenge himself not only as a coach, but also as an athlete, competing in sprinting events, strongman and Olympic-style weightlifting.