While some people exercise because we enjoy our sport or leisure activity, there are also those who exercise primarily because they'd like to lose some weight. Shedding body fat motivates thousands of people to go to the gym or to pound the streets, but some may not be doing the right forms of exercise to truly kick start their weight loss programme.
Fuelling for exercise
The two main sources of fuel for our bodies are fats and sugars. Our sources of fat are used to provide our bodies with the energy it needs to exercise over long periods of time, while sugar is used for higher-intensity work outs. However, both sources are needed at all times.
Our bodies are always burning calories, even when we're sitting still or even sleeping, and physical exercise increases the amount of calories our body uses. The ratio of fat to sugar our body uses when sitting down is roughly 60% fat and 40% sugar,1 although we'd only be burning one or two calories a minute.
If we were to get up and jog we'd need a quick burst of energy, so the ratio of fat would decrease to 30%.1 However, the fat ratio would steadily increase to around 60% if we were to jog for a longer period of time. If we were to sprint or take part in more vigorous exercise, the ratios shift towards sugars to provide the energy we need.
There is a belief that people will burn more fat by taking part in low intensity exercises, such as walking or gentle cycling for 20 minutes or more. While these exercises use more fat reserves than sugar, they will not burn as many overall calories as vigorous exercise, and it is burning calories that really influences weight loss.
Essentially, the harder and longer your workouts are, the more weight you are likely to lose.
Types of exercise
To maximise weight loss, it is important to combine both cardiovascular and resistance exercises together. Cardiovascular exercises, such as running, swimming and cycling will help to build your fitness, but the key to good cardio is to choose a type of exercise you can carry on for a longer period of time - ideally at least thirty minutes or more.
While many people think that resistance training is purely for building muscle, combining it with cardio greatly increases the number of calories burned, while it can also increase your metabolic general metabolic rate. These exercises include using weights machines, dumbbells, resistance bands or even good old body weight exercises such as push ups.
Principles of maximising weight loss
There are several key principles you should follow to maximise your weight loss through exercise. These include:
- Exercise intensely to maximise calorie burning, and increase the intensity as you get fitter. Remember, 'intensely' is a relative term - don't over-do it and always work safely within your limits.
- Pick exercises you enjoy, as this maintains motivation and makes them easier to keep up.
- Exercising larger muscles burns more calories than smaller muscles. The key groups are the thighs, chest, back and bottom, so using a rowing machine at the gym can be highly effective.
- Use weight bearing exercises where you can. Non weight bearing exercise, such as swimming, can be a great way of building up general fitness, but it doesn't protect against osteoporosis (thinning of the bones). In addition, running can use more calories than swimming or cycling thanks to using your body weight against gravity.
- Ensure your exercise is sustainable. You're unlikely to see any benefits if you can only skip for two minutes, so try something you can take part in for a longer period of time - at least until you have built up your fitness.
- Use interval training, mixing relatively intensive exercise bursts of one to two minutes with easier periods of similar duration. Six to eight sets of this in a session and you'll really reap benefits.
- Don't exercise hungry, as a well fed body will be able to work harder and longer and burn more calories.
Remember - minor aches and niggles are common and normal during exercise but if you start to feel an increase in discomfort then stop immediately. If you recover, then carry on gently and give it another go but if you start to feel uncomfortable again then you should probably call it a day.
If you have any medical conditions, injuries or disabilities that either affect your ability to exercise or which may be worsened by exercise, then you should take specialist advice from your doctor or suitably qualified healthcare expert.
1. Physiology of Sport and Exercise; Wilmore, J.H. and Costill, D.L. Human Kinetics 1994