Express exercise: Fitness expert Kris Abbey gives us short cuts to slimming down and getting super fit

 By Kris Abbey, Fitness Expert / 

Most of us are time poor and don’t have time for long gym work-outs. So we asked our fitness expert, Kris Abbey, for short-cuts to burn fat fast and get fit, strong, and powerful. Interval training, here we come!

The trick to achieving results is pushing yourself outside your comfort zone.

You only need to push yourself for a short period of time and then allow yourself a break to recover before doing it again. Say 30 seconds hard effort followed by 30 seconds active recovery (walk around, or continue what your doing with less intensity) and then do another intense burst. This is what we call interval training, or more specifically, High Intensity Interval Training (HIIT).

The concept is simple, yet the results are vast. To fully appreciate what this actually does to your body entails opening up a discussion about lactic acid, oxygen debt and recovery. This can become quite complicated (read: boring), so I’ve broken it into ‘intervals’ for easier understanding.

Creating an Oxygen Debt
Are you wondering since intense exercise burns a lot of calories, why we don’t just don’t push hard the whole time? If I have 20 minutes, shouldn’t I make the most of this and go hard for 20?

Firstly, the intensity I am referring to wouldn’t be sustainable for 20 minutes. Also, when you do a sprint or an intense circuit, your body can’t supply oxygen at a rate fast enough to fuel the muscle.

Your anaerobic energy system (creates energy without oxygen) has to kick in to help provide the extra energy required by the working muscles. After the intense effort is completed, your body has to basically repay that “borrowed energy”. This requires oxygen to get those muscles back to their normal state, and the oxygen required is called the Oxygen Debt. The more energy your body borrowed during an intense effort the more oxygen it owes, or the greater the Oxygen Debt.

A Large “Oxygen Debt” is Key in Boosting the Metabolism
After an intense effort, like a 30 second sprint, you’re breathing hard and your heartbeat is raised…this is your body’s way of repaying the oxygen debt. The extra breathing draws the oxygen in and the extra heartbeats circulate the oxygenated blood back to those muscles. Your metabolism is operating at a higher rate (breathing and heart rate) to repay the oxygen that it borrowed. I’m simplifying this a little bit, but you get the basic ‘oxygen debt’ principle.

The larger the oxygen debt created by your workout the longer it takes to repay it. This means you will continue to burn calories even after you’ve stopped exercise. This may be up to 24-48 hours after you have stopped, depending on length and intensity of your workout.

Creating an Oxygen Debt
This is a bit like a monetary debt, once you’ve used your cash, any spending after that puts you in debt. Our body is no different. To create an oxygen debt, the effort has to be intense enough to exhaust aerobic energy and draw upon anaerobic energy, which creates the debt.

The reason intervals and circuits training work so well is that you are performing the next intense effort before you catch your breath or have had the chance to fully repay your debt!

This combination of intense effort while already breathing hard is the best way to create a maximum oxygen debt. And this, my friend is one of the best ways to boost your metabolism, and therefore burn more fat.

And it gets better
If you’ve ever pushed yourself to the point you get a metallic taste in your mouth, you know you’ve reached your lactic acid threshold.

Lactic acid is produced as the result of intense effort and it was believed that training within this threshold was not a good thing. Professor Thomas D. Fahey of California State University thinks differently.

“The body converts glucose, a substance removed from the blood only sluggishly, to lactate, a substance removed and used rapidly. Using lactic acid as a carbohydrate middleman helps you metabolise carbohydrates from your diet, without increasing insulin or stimulating fat synthesis.”

So, in simple terms – lactic acids helps your body burn more carbohydrates and ultimately more calories…further assisting your fat burning efforts.

Increasing Lactic Acid
We covered how pushing hard before fully catching your breath increases oxygen debt, it is also a way to increase lactic acid.

After an intense effort, you accumulate a bit of lactic acid in the muscle and then your body begins to remove it. You want to perform another intense effort before the body is recovered to assist the body in accumulating more lactic acid in your muscles. With enough intervals, you will have a buildup of lactic acid, and because of this, your body will be able to burn more calories than normal after your workout is finished.

Again…An intense effort for a short time is what it takes to increase lactic acid. Have a short rest, but not to a complete recovery, and go again. This is the basic premise of interval training and keeps you producing lactic acid, while creating and oxygen debt. These two things combined give you the ultimate fat-burning, results-achieving workout.

A good HIIT routine should allow just enough rest to be able to push hard for the next intense effort, and be at least 30 minutes in duration. And if you’re breathing…and you should be breathing pretty damn hard when the whole series of intervals is finished, you know fat is being burned, metabolism is raised and fitness has been pushed… all adding up to a great result!

Kris Abbey is the publishing editor of Better Health and Spa Life Magazines.

Kris Abbey’s other RESCU blogs:

  1. The truth about muscles: how you can slim down and tone up with LESS effort
  2. The secrets to a firmer, flatter stomach in two weeks
  3. Kris’ kick arse plan for a better butt
  4. Getting the most out of weight training

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