Is your calorie bank in the red?

This time of year is the 'off season' for me and I don't mind taking on an extra kilo or three but come pre race season I know that I am going to have to go back to my calorie bank and check my account balance to see if I am in the red, or in the black.

My daily calorie baseline may be different to the needs of another woman's and that's where I like to use cycling and triathlon coach Gale Bernhardt's formula for assessing my calorie needs.

According to Gale everyone has daily baseline calorie expenditure, just like a savings account in a bank. These are the calories it takes for you to keep going on a daily basis. To sustain your daily life, that's just the normal things you do such as eating, sleeping, talking etc, each day you need approximately 30 calories per kilogram of body weight.

I weigh 63 kilograms. So that is 63 x 30 = 1890 calories. That's just to operate all body functions at a normal level. Approximately 78 calories an hour on average.

Apart from my daily baseline calorie intake I also need to modify my calorie intake when the situation demands.

To modify the base formula:

Add more calories (about 100 to 300) to the daily total if your lifestyle is active. Delete calories is your lifestyle is very low in activity.

The following modifiers are gross values that include exercise expenditure and the base energy expenditure.

  • Add about 0.15 to 0.17 calories per minute, per kilogram of body weight for cycling. For example 0.17 calories/minute x 60 minutes x 63 kilograms = 642 calories needed for an hour of fast cycling (time trialling or training in conditions that make you work hard).
  • Add about 0.1 calories per minute, per kilogram of body weight for strength training. For example 0.1 calories/minute-kilogram x 60 minutes x 63 = 378 calories need for an hour of strength training.

If you weigh 63 kilograms and you did a killer-hard, one-hour bike workout, your calorie expense account for the day is roughly your base needs plus your exercise calories. Don't forget to remove your base calories from the hourly exercise number: 1890 calories + (642 - 78 (calories for that hour)) = 2452 calories for the day.

While the above formulas are a good start, you need to find ways to hone in on what you really are expending in calories when you exercise and what you expend during normal activity.

For those of you who may obsess about your weight here are a few words of advice. "There are some days when you eat more than you need for one reason or another," Gale said. "There are also going to be days when you exercise more and expend more calories than you burn. Eating 200 calories too many on one day is no big deal if you expend an extra 200 within the next couple of days."

Keep track of what you eat for about three days to see what you are consuming to maintain your current weight. Make adjustments if you want to put on weight or lose weight. Do not drop below 1500 calories per day. "This slow approach to weight loss reduces the risk of compromising your health through reduced food intake," Gale said.

One way to calibrate cycling exercise is with a power meter that displays calories burned for a workout. If you power meter says you only expended 400 calories for an hour of high intensity workout that needs to be taken into your calorie budget.

I personally prefer to use a heart rate monitor, which I can use in my running and swimming exercise as well. It has proven to be more value for the dollars than a power meter. And it provides me with the data I require such as calories burned as well as what heart rate zone I am training in. But that's a whole new topic for another article.

Reference:The Female Cyclist - Gearing Up A Level. Gale Bernhardt. Velo Press.

This reference book is available from the SheSpoke Bookshop.