Chewing The Fat

John Shepherd, a.k.a. Ultra-FIT magazine's Gym Rat, has been asked numerous questions about fat burning and fat loss over the years. Here the 'Rat' provides Indoor Sport Services readers with the answers to some of the most commonly asked questions.

  1. How can I strip fat forever and get fit?
  2. Is CV exercise the only exercise suitable for fat burning?
  3. So how does weight training burn fat?
  4. What's wrong with the traditional concept of the CV Fat Burning Zone (FBZ)?
  5. Why can higher intensity CV workouts be a better weight loss proposition?
  6. The importance of glycogen
  7. Why can it be more beneficial to eat five to six meals a day, rather than two or three?
  8. Are some people less able to burn fat than others?
  9. What can be done if you have been training for a long time and are having difficulty losing more fat?
  10. Why can quick weight loss be disappointing in the long run?

How can I strip fat forever and get fit?

Go down to your local gym and use a rowing machine. If you row for about 45 minutes to 1 hour each day at a steady 2 minutes 10 seconds per 500m pace, you'll burn around 600 calories. Do that every day for a week and you'll have burnt 4,200 calories. Even if you made no changes to your diet, at the end of the week you could have lost half a Kg of fat.

As you get fitter you will become more exercise efficient, so to burn the same number of calories each workout you'll have to increase the time or the pace at which you row.

TRAINING TIP: Never increase the intensity and the length of your workouts at the same time.

Is CV exercise the only exercise suitable for fat burning?

The answer is a definite no. Weight training, all sports and fitness activities, gardening and other day-to-day activities all burn fat. What you specifically need to be concerned about is 1) the total number of calories burned - whether fat or carbohydrate and 2) the effect the exercise type has on your body composition in terms of promoting and maintaining increased leanness (non-fat weight).

TRAINING TIP: For optimum fat burning and great body shape, Cross-train - that's combine resistance and CV work in your training - which is what most indoor rowers do.

So how does weight training burn fat?

"You won't burn so many calories weight training (see table 1), but the potential effect it will have on your body composition and metabolic rate are significant," explains the Rat.

Table 1: Fitness activities and calorie burning

Activity calories/hour
Aerobics high intensity520
Rowing - slow400
Weight training270-450
Swimming for fitness630
Treadmill Running (3.8min/km)1000
Treadmill Running (5.6 min/km)750

The above figures are based on a 65Kg individual. If you weighed more then additional calories will be expended, fewer if you weigh less.

Muscle is the most metabolically active part of your body, burning up to three times as many calories as any other tissue type. Weights (and other forms of resistance training, like circuits) promote the development of lean muscle, boosting your fat burning potential.

Research indicates that a 0.5Kg increase in muscle will up your weekly calorie burn by 350 Kcal.

TRAINING TIP: Weight train before your CV workouts if performing both activities in the same session. This will allow you to lift strongly and CV train at a medium intensities.

What's wrong with the traditional concept of the CV Fat Burning Zone (FBZ)

The FBZ refers to CV workouts performed in the 60-70% of heart rate max (HRMax) for a minimum of 20 minutes.

There is actually nothing wrong with the concept of the FBZ, what is erroneous is the belief that it's the best and only way to burn fat. We've already noted that any form of exercise burns calories. The FBZ was developed for a number of reasons.

1) Client safety and confidence. Rowing or running at a very easy pace for 20 minutes is not too far beyond most people's grasp when they commence an exercise programme. It is a target that can easily be attained;

2) Fat is burned at a proportionally higher rate at lower exercise intensities - see table 2. However, this as we shall see later is not really a crucial consideration for sustained fat loss;

These reasons are why FBZ workouts are often promoted; the problem then is that they become cemented into people's minds as the 'only' way to burn fat. FBZ workouts do have a place in a general fitness regime, but there are far more effective ways to continually burn fat once a level of fitness is achieved that will allow for higher intensity training to take place.

Some full-time athletes do go for long walks or slow runs to specifically burn fat, but this is in addition to their normal high-level training. Their leisurely efforts should be regarded as icing on the cake within their overall training plans and not a singular justification of FBZ workouts.

Anyone training in the various zones indicated in the 2K training manual, will burn large numbers of calories, which will lead to fat loss.

TRAINING TIP: If you are an advanced trainer use lower intensity efforts as recovery sessions between your higher intensity ones.

Why can higher intensity CV workouts be a better weight loss proposition?

Higher intensity workouts are carried out above 75% HRmax. You'll get a much greater return from these. Take a close look at the contents in table 2.

Table 2: Carbohydrate and fat calorie burning averages at low to high exercise intensities.

Exercise Intensity % of Kcal from Energy Expenditure (Kcal)
Carbohydrate Fat Per min After 20 min
Low 33.4% 66.6% 9.6 192
Moderate 50.7% 49.3% 12.2 244
High 84% 16% 15 300
Very high 100% 0% 20.2 404

Try to forget about where the calories burned come from what really matters is the total calorie burn for weight loss - the higher the intensity the higher the calorie burn and the more significant the potential effect on fat loss. This is because:

1) Burning greater numbers of calories can produce an energy deficit in your body, which may not be fully recoverable by your eating habits. This is especially the case if you deliberately control your energy consumption through your eating to achieve a 'negative energy balance'. A negative energy balance is achieved when you take in less calories than you would need to balance your energy in and energy out needs on a daily basis. Do note that for optimum fat burning and weight loss you should only achieve this deficit two days of the week. Creating an energy deficit more regularly will run the risk of a) not taking in sufficient calories to supply your body with enough energy for your daily and fitness needs b) risking metabolic slow down. Those training for indoor rowing races will probably need to eat more than normal (especially carbohydrates) due to the high energy demands placed on their bodies by their preparation.

2) Post exercise calorie burn and an increase in metabolic rate. Higher intensity efforts can create a positive post workout legacy of calorie burning, when your metabolic rate remains elevated. One piece of research indicated that this could be increased by 8 to 14% for those who train regularly and intensely - that's equivalent to 143 and 286 Kcal a day.

The importance of glycogen

When you exercise carbohydrate in the form of glycogen stored in your muscles, tends to pick up the energy tab. Glycogen is muscle fuel. Rather like money you can run out of it easily, as the body can only store it in limited amounts (on average only 425 grams). That's enough for you to run or walk around 16 miles). In consequence you need to consume sufficient carbohydrate (see below) and follow a balanced training programme to permit the optimum conditions for glycogen replacement.

Even if a workout could be devised that gained all its metabolic power from your body's fat supplies and didn't touch your carbohydrate (glycogen) stores there'd still be a problem. Your body would be unable to create further glycogen from carbohydrate. This is because its store cupboard would be full, so it would have no other option but to turn this excess into fat.

TRAINING TIPS: Aim for 2g of carbohydrate per Kg of body weight and 1.4g of protein per Kg of body weight per day.

AND: For those of you rowing for fat loss, only reduce your daily calorie consumption by no more than 15% on the two days a week when you create a negative energy balance, to avoid metabolic slow down.

Why can it be more beneficial to eat five to six meals a day, rather than two or three?

"Don't stuff yourself with a four course meals every four hours throughout the day," implores the Rat adding, "but five to six smaller meals can actually make you a more efficient fat burning machine."

Eating burns calories as well as providing them. This is called the Thermic effect of feeding (TEF). TEF accounts for 10% of your total daily energy expenditure. Eating regularly and sensibly will add to your calorie burning, energy maintenance and will prevent metabolic slow down.

EATING TIP: Fats have very little effect on TEF, carbohydrates and protein are much more beneficial. Aim for 55-60% of your total calorie consumption from carbohydrate, 15% from protein and the rest from fat. Avoid saturated fats, as found in sweets and cakes.

Are some people less able to burn fat than others?

Research has substantiated this. The difficulty is determining whether you are better at fat burning than someone else. Specialist testing equipment is required. Some people can burn significant amounts of fat at high CV exercise whilst others max out at much lower levels. You could use your rowing machine to calculate what camp you fall in. Do note that even the latest C2 erg only estimates your calorie burning; note also that exercise familiarity also curbs calorie burning. So if you always row 5,000m a day at 1:55 pace the chances are that over a period of time your calorie burning potential will decrease.

What can be done if you have been training for a long time and are having difficulty losing more fat?

If you are an experienced trainer and are striving for further realistic fat loss, then take a serious look at your training and look to overhaul it regularly. This will provide your body with a fresh stimulus and will optimise the long term potential for continued fitness improvement and fat burning. It's very similar to training for a 2K race, where layers and layers of specific fitness are built on top of each other to achieve optimum race condition.

TRAINING TIP: For fat burning rowing purposes, try to alter the emphasis of your training every 12 to 16 weeks; perhaps building up from slower CV efforts to more intense ones and/or emphasising weights and other resistance training methods.

Why can quick weight loss be disappointing in the long run?

Your body finds it much easier to burn carbohydrate in the form of glycogen rather than fat. The Rat previously noted that the body cannot hold onto glycogen and that it must continually be replenished. Fat on the other hand can hang around like an unwelcome party guest. Fat also weighs much less than glycogen. "You should just be starting to hear the penny drop now for the consequences for quick weight loss," explains the Rat adding, "If you weigh yourself after a workout, chances are you will be lighter, but as fat heavy." Reduced glycogen (and water loss) will skew the figures. That's why dieters often get disillusioned after initial enthusiasm with quick weight loss. If exercise levels are reduced or if eating habits return to pre-exercise/diet levels then the chances are that the weight will return largely because your body has restocked with glycogen. Also diets where insufficient calories are consumed for everyday needs run the risk of turning your body into a poor fat burner - this is because it will hang on to every calorie it gets in fear that the next one will be a long time coming. This is a genetic predisposition dating back to well before the Model A Indoor Rower, when our prehistoric ancestors could not rely on when their next meal would come.

TRAINING TIP: A lack of glycogen will also seriously affect your training potential, so to reiterate don't starve yourself and follow the guidelines provided in this article if you want to optimise your fat burning and training.

AND: Do not yo-yo diet as you can set your body's fat burning dial at a very low level. A period of calorie restriction can alter your body's 'set point' for burning fat and maintaining leanness. Once this is in the low range, weight can easily be put on.