Cardio for fat loss and The Law of Diminishing Returns

What a contentious issue cardio is. Do you do short high intensity sessions, long steady sessions, morning cardio, post workout cardio, cardio in a fasted state, in your "target heart rate zone".....? The area of cardiovascular exercise as a tool for effective fat loss is a hotly debated topic among coaches and athletes worldwide and can be as confusing as my old university physics professor.

However a rarely acknowledged facet of cardio for fat loss is what I like to call The Law of Diminishing Returns or "the more you do the less you get" theory.

You see you're not designed to have crisp, visible abs and a slim, tight butt. Oh no, your body wants a nice soft, blubbery coating of fat just in case you get lost in the bush while hunting woolly mammoths. You need the fat so that you don't starve to death while trying to find your way back to the cave. What's that you say, you don't hunt mammoths for dinner, you go to the refrigerator? Well your metabolism doesn't know that, for as far as it's concerned you are still a Stone Age hunter-gatherer and survival of the species is your main concern.

Game show or reality?

Which brings me to what I see as the biggest problem with cardio and fat loss - your fat loss has stopped from too cardio much, too soon. People usually come to me when their fat loss has stalled or they are at the end of their tether after years of yo-yo dieting. And what's the first thing you do to keep up the fat loss? Increase the time, intensity and number of cardio sessions, right? After all that's what the trainers do to the contestants on The Biggest Loser.

Well I'm here to tell you that's all wrong!

If you are doing an hour of cardio in the morning, six days a week and cardio at night after your weights workout (or step class / boxercise / spin class), and you haven't reached your fat loss goals, how are you going to increase your cardio? Where do you go from there? Three hours a day, seven days a week? You'll have to quit work and divorce your family just to find time for your cardio.

As well as the time factor you have to take into consideration a host of feed-back mechanisms and hormones, developed over millions of years of evolution, fighting to keep you fat. You have built in warning signals that are triggered when energy supplies are low, fat stores are being depleted and when you are tired, sore and cranky.

That's when these feed-back mechanisms and hormones sabotage all your efforts, telling you to overeat and making your metabolism slow down. The result is your fat loss stops, or worse still, you gain weight. Hence, The Law of Diminishing Returns.

Develop a simple plan and stick to it

But don't worry, all is not lost. You can beat The Law of Diminishing Returns with a simple plan. All you have to do is "control the variables"- diet, cardio and weight training. You need to be constantly monitoring what you are eating (remember calories in calories out); how much cardio you do and how long you are doing it for and, your progress in the weight room.

When I prepare a plan for a new client I want to start them off eating the maximum amount of food possible, doing the minimum amount of cardio and all the while seeing significant fat loss. Cardio may be as little as 20 minutes three times per week when calories are being closely controlled. That way when the fat loss slows or stops we can make gradual increases in cardio time or intensity.

Granted, if we were to jump straight into an hour a day of cardio there certainly would be significant fat loss. But as I explained earlier, that one hour will not be enough in a few weeks time. And where to from there?

By using a minimum amount of cardio at the start of the diet we have a number of options to keep fat loss efforts on track. We can make a small increase in time; increase intensity; add another session or choose a more difficult form of cardio to increase energy expenditure.

Monitoring your progress is as simple as a one line entry in a training journal noting the day, time, intensity, type and duration of your cardio. Coupled with your calorie controlled diet, overcoming The Law of Diminishing Returns is as simple as developing a plan and sticking to it.