A great physique is built on three pillars – resistance training, diet, and cardio. And while each is just as important as the others, the one that most people seem to have the strongest feelings about is cardio.
Part of the reason for people either loving it or hating it is the fact that on the one hand, cardio can be mind-numbingly boring. And on the other hand, it can be brutally challenging, both physically and mentally.
Just as people’s feelings about cardio can vary between extremes, so too can their opinions about how much needs to be done. Even among fitness competitors, I’ve heard of some who do two cardio sessions a day as a normal part of their routine, even in the off-season, and yet others who can get absolutely shredded for a show with only 3 to 4 hours of cardio a week.
Why the big variation? Is it just that everyone’s body is different?
Well, that’s certainly part of it. We all have different physiologies and genetics, so naturally we can’t expect everyone to do exactly the same amount of cardio and get the same results. But there’s more to it than that.
The fact is, whether you’re a fitness competitor or just someone trying to get into better physical shape, you actually “train” your body, in a way, to either need more or less cardio, just by the way you eat and work out.
Now, if you value your time, or if huffing and puffing your way through punishing cardio sessions isn’t exactly your idea of a good time, then you owe it to yourself to learn how to use it as effectively as possible, so that you can be doing the right amount of cardio to get maximum results with minimum time and effort.
Do you need to do cardio at all?
If physical fitness or sports performance isn’t your primary goal, but rather you’re just trying to lose body fat to improve your physique, you may be wondering whether cardio is actually even necessary at all.
Well, strictly speaking, no it isn’t. It is actually possible to lose body fat purely by manipulating your diet alone. But there are a few reasons why you wouldn’t want to do that.
Most significantly, your rate of fat loss would be painfully slow.
To lose weight you must create a calorie deficit, meaning that your daily calorie expenditure needs to be higher than your daily calorie intake. There are two ways to achieve this – reduce your calorie intake by eating less, and increase your calorie expenditure through cardio exercise.
The best approach by far is to use both of these strategies, since that will allow you to achieve the most rapid results.
Unfortunately, the amount by which you can reduce your calorie intake is quite limited. That’s because the more you do so, the more your body will undergo metabolic adaptation, or metabolic damage. This is where your metabolism slows down in response to the reduced energy available, causing it to burn fewer calories.
This, of course, directly opposes what you’re trying to achieve and is therefore something you want to avoid as much as possible.
Resistance exercise goes some way to minimizing metabolic adaptation, but even so your body won’t allow you to reduce your calorie intake too far before it becomes problematic. This therefore limits you to losing body fat quite slowly, unless you supplement the calorie deficit with cardio exercise.
An important added benefit of cardio exercise is that it improves your level of cardiovascular fitness. This allows you to work harder during your resistance training, as well as recover more quickly. From this perspective, cardio exercise and resistance training really work hand in hand in building your strength and physique.
What’s the best type of cardio to do?
Understanding what type of cardio to focus on for fat loss is very important to your success. That’s because some types of cardio are far better than others for helping to create a calorie deficit to burn body fat.
Low intensity, steady state (LISS) cardio suffers from same problem as a dietary calorie restriction of leading to metabolic adaptation over time. You will get immediate fat loss benefits from LISS cardio by the additional calories burned. But over time as your body gradually adapts to the cardio, not only it will become less and less effective at consuming calories, but your metabolic rate will also gradually slow down.
This leads to a situation where you’re fighting an uphill battle that ultimately ends up as a plateau, where your fat loss finally stops altogether. This is much the same as if you were simply trying to lose weight by cutting calories alone, albeit perhaps not as rapid.
By focusing on high intensity cardio exercise, however, you avoid this problem.
Scientific studies have shown that not only does high intensity exercise such as High-Intensity Interval Training (HIIT) and high-intensity circuit training not lead to metabolic slow-down, it actually increases your body’s fat-burning effectiveness. Unlike LISS training, your body also doesn’t adapt to the exercise itself anywhere near as readily, so it continues to be an effective way to burn fat into the longer-term.
This doesn’t mean that you need to avoid LISS training altogether. Any good training program includes a variety of training methodologies for best results. You should however focus more on high-intensity training with just occasional LISS training sessions.
An added benefit of focusing on high-intensity cardio is that it improves your anaerobic fitness as well as your aerobic fitness, something that LISS cardio doesn’t do. This allows you to work harder throughout your resistance workout, since this in itself is an anaerobic activity.
How much cardio do you need?
There’s an old saying in motor racing that you should win a race as slowly as you can, and the same thinking is true of cardio for fat loss. You should do only do enough to get the job done, and no more. For some people that may be a couple of hours a week, for others a couple of hours a day.
If someone does need a couple of hours of cardio a day to lose weight however, that’s a clear indication that they have a serious problem with their metabolism. They’ve either starved themselves and/or accustomed their body to too much LISS cardio, and their metabolism has adapted accordingly. At that point they’re fighting against their body rather that working with it, and that’s always a losing battle.
There are numerous people out there who believe they “need” a lot of cardio to lose fat. That may be true, but the point is it isn’t normal, for them or for anyone else. They often believe that that’s just how their body is, but that simply isn’t the case. It’s not something that’s built into their physiology or genes, but rather, largely a result of their actions. It shouldn’t be and doesn’t need to be that way, for anyone.
By taking the time to restore their metabolism back to good health through reverse dieting, and perhaps even replacing their LISS cardio with high-intensity cardio if appropriate, they would then find that fat loss comes far more easily when done the right way.
In fact this is highly recommended for anyone struggling to lose weight, at any time. If you find it difficult despite having a fairly low calorie intake and despite doing cardio exercise regularly, then you need to focus on allowing your metabolism to recover before concerning yourself with dieting further.
So what’s the right amount of cardio?
There is no hard and fast number for how much cardio is the right amount, each individual will be different. It depends on your metabolism, your physiology, how much you work out, how much weight you’re intending to lose, how slowly you’re willing to lose it, and so on.
The amount of cardio you do goes hand in hand with the amount of calorie restriction you introduce into your diet, since the two work together to create your overall calorie deficit.
The best approach therefore is to start conservatively, with perhaps about two cardio sessions per week and a moderate calorie restriction. You can then adjust the two as required depending on your weekly fat loss, bearing in mind the following points:
- The slower you lose fat, the better. This helps to avoid metabolic adaptation which means you reduce the number and severity of plateaus as you move toward your goal weight, and also drastically reduce the chance of re-gaining weight afterwards.
- A maximum target figure for weekly fat loss should be about 2lb. For someone with a lot of body fat to lose however, this figure can be exceeded. It’s not uncommon to lose a large amount of body weight in the first one to three weeks of dieting, although this is normally because some contribution is made from loss of water and undigested food. Losing more than 2lb of body weight on an ongoing basic almost certainly means that you’re losing muscle as well as fat.
- In most cases a target figure for weekly fat loss should be about 0.5lb to 1lb.
- When your weight loss begins to plateau you can reduce your calorie intake and/or increase the amount of cardio to break the plateau. Sometimes just changing the type of cardio you do can also break a plateau.
- At no time should you allow your calorie intake to drop too low, as this will cause excessive metabolic adaptation which will take a lot of cardio to overcome. The minimum level is different for everyone, but under no circumstances should you ever go below 1,200 calories a day.
- Rather than allowing your calorie intake to drop too low, it’s preferable to add cardio instead. It’s always better to burn off calories than to starve them off.
- Always keep in mind that high-intensity cardio is far less likely to contribute to plateauing of your weight loss than LISS cardio. You should therefore focus more on that, especially if you’re finding your progress slow.
- It’s not easy to put a maximum figure on how much cardio you should be doing per week. There should never really be a situation however where you’re doing more than one session a day or more than 5 to 6 sessions a week as a maximum.
If you find you need more than this then as I mentioned earlier, you most likely have some metabolic issues that should best be addressed through reverse dieting before proceeding with your weight loss.
Cardio is not a religion!
As you can see then, cardio exercise is simply a tool that you need to use purposefully and strategically for fat loss. It’s not something that you do a certain amount of each week religiously, “just because”.
From that perspective it’s very much like your diet, where you’re taking in the appropriate amount of calories to get the job done. Too many and you stop losing weight, too few and you experience metabolic slow-down, and then you stop losing weight.
With cardio if you do too little, you lose weight slowly or not at all. Do too much LISS cardio and you experience adaptation and metabolic slow-down.
Good trainers and coaches ensure that their clients maintain a healthy metabolism and have them doing the minimum amount of cardio necessary to lose fat at an appropriate rate. On the other hand, poor trainers and coaches who don’t know any better have their clients busting their butt with hour after hour of cardio needlessly.
How much cardio exercise are you doing at the moment, and what type do you focus on? How’s it working for you? I’d love to hear your feedback in the comments below!