Don't be fooled into thinking that long, slow cardio is the most important aspect of fat loss. How many times have you been in the gym and seen people on the treadmill for 40, 50, 60 minutes or even longer? Is this the best way to train? It depends on your goals. If fat loss is your goal then good nutrition and weight training are far more important than long, boring cardio sessions. Add some interval training to the mix and you are well on your way to melting fat fast. Research shows more fat is lost both during and after interval training when compared to steady state cardio.
Recent research conducted in Quebec and also here in Australia showed that high intensity interval training is more effective for fat loss than low intensity "aerobic" training. The Australian study found three 20 minute sessions per week for 15 weeks resulted in three times more fat loss than three 30-40 minute sessions at 60% VO2 max. If fat loss is your goal, forget about working in the "fat burning zone" and put your energy into some intense interval sessions. You'll work harder, shorter and smarter by following this approach. Best of all you will burst through your fat loss plateaus.
If you are anything like me, the idea of letting go your title of "cardio king" or "cardio queen" might be a little daunting. You have come to believe that the more cardio you do, the better and might even find it quite enjoyable even though it does take several hours out of your week. You don't have to give your long cardio sessions up altogether. So is there a role for slow, steady cardio exercise? You bet there is! But if fat loss is your goal this should not be your primary means of exercise. Steady state cardio is suitable for deconditioned people - for instance someone who is returning from an injury or surgery or someone that has not done any exercise in a long time. It's also good for people that want to improve their aerobic fitness - perhaps to participate in a fun run or triathlon but mix it up with intervals. Too much long slow cardio is wasting your valuable time and energy reserves.
It can also contribute to overtraining and cause cortisol levels to rise (which will impede your ability to burn fat and actually cause you to store it -exactly the opposite of what you want if you are trying to get lean). Aerobic exercise has many benefits and it will work for fat loss but it is not the best method. The reason for this is that it doesn't burn as many calories when compared to interval training. Secondly it does very little to increase EPOC. We talked about EPOC previously. Basically when you do slow steady cardio the calorie burn stops the moment you step off the treadmill (bike, crosstrainer etc). However with weight training and interval based cardio, you continue to burn calories even AFTER you finish exercising. This type of training causes a greater metabolic disturbance in your body and will get you on the road to results. It will have you have you burning calories while you sleep which is a VERY good thing.
What about the "fat burning zone" indicated on the cardio machines. Shouldn't I be exercising there?
Some of the cardio equipment has a table depicting what your heart rate should be if you want to work in the fat burning zone. There really isn't anything magical about this fat burning zone and the new research indicates that this isn't the most effective way to burn fat. Working in the fat burning zone is a lower intensity workout compared to high intensity interval training and will NOT burn as many calories overall. In the fat burning zone you will burn more energy as fat relative to the other zones but this does not mean you burn more fat overall. This is where most people are being duped. Relative fat burn is not the same as overall fat burn. The fat burning zone is fine for people who are deconditioned (as discussed above) but everyone else should be doing intervals or working at an intensity above and beyond that in the "fat burning zone" and training in a way that elevates metabolism all day long so that fat can be burned 24/7.
How do I do high intensity interval training (HIIT)?
Ideally you would do your intervals 3 times a week. On the other days try to do some light exercise for half an hour. This could be a walk around your neighbourhood, doing some work in the garden or a low intensity cardio session at the gym (yes this is your chance to do some steady state cardio if you wish to do so). When you are doing your intervals you really want to challenge yourself. Interval training simply means that you alternate between working hard and "resting". The rest period is an active rest so you don't hop off the bike or treadmill and sit down for a bit; but rather you keep your body moving but at a much gentler pace than when were in the work phase. An example of interval training on a treadmill would be running for one minute then walking for two minutes and switching back and forth between the two for a total of 15 minutes. As you become fitter you might run for one minute then walk for one minute (shortening the "rest" period). Someone more advanced might alternate between sprinting and jogging while a beginner might alternate between a fast walk and a slow walk. The speed or level you work at will depend on your fitness but the work phase should be equivalent to an 8 out of 10 in terms of perceived difficulty. If I tapped you on the shoulder halfway through your interval session and asked you how hard this was, with 1 being easy and 10 being really tough, I'd want you to be at an 8.
An interval program consists of a 3 minute warm up, 12-14 minutes of interval work where you alternate between short bursts of work and active rest, then a 3 minute cool down. Your whole cardio session is finished in 20 minutes! Woohoo!! The work phase should never last more than 2 minutes. If you can do more than 2 minutes then you are not pushing yourself hard enough. I tend to vary my intervals from one workout to the next. For instance one day I might work for 45 seconds and rest for 45 seconds and on another day I might work for 30 seconds and rest for 10 seconds. Mix it up so that your body never knows what to expect. The only other rule is to alternate between work and rest for a maximum of 12-14 minutes. If you have pushed yourself hard, this is long enough and if you do any more you will start to burn muscle rather than fat. Finish with a cool down (working at a gentle pace for 3 minutes) and you are all done.
When should I do my intervals?
You can do your intervals after your weight training or you can do it on the days between workouts. The most important thing is that you don't do intervals BEFORE you do your weights. Personally I like to do weights three times a week (Mon, Wed, Fri) and then I do my intervals immediately afterwards. On my days "off" I take my dog for a half hour walk.
What equipment can I use?
When doing intervals you are only limited by your imagination. The most straightforward way is to use the bike or treadmill. On the bike you want to have the resistance up high for your work period and drop the resistance down for the rest period or pedal very slowly. The treadmill is also good for intervals but there is the danger of falling off the treadmill especially when doing explosive runs and sprints. The bike is the safest and most straightforward option for the beginner but equally suitable for the more advanced exerciser. You can also use the cross trainer, rower or stairmill. You can do intervals without any equipment at all. For instance you could walk and sprint in a park or you could walk on the spot and skip with a jump rope in your living room. I enjoy getting out onto a sports oval and sprinting across the field and jogging slowly back. I repeat this 10 times and then I am all done.
