Calculating your calorie demand

Calorie demand depends on age and gender. The minimum requirement for women is 1500-1600 kcal/day, for men: 1800-1900 kcal/day. This amount of energy is required for basic life functions like breathing, digestion and blood circulation.

Athletes use 3500-4000 kcal/day on average.

Daily basic metabolic needs calculation (kcal/day)

Age (years)              Men                                   Women

10-17 17.5 x body weight + 651 12.2 x body weight + 746

18-29 15.3 x body weight + 679 14.7 x body weight + 496

30-59 11.6 x body weight + 879 8.7 x body weight + 829

60+ 13.5 x body weight + 487 10.5 x body weight + 596

Source: Rodler: New Nutrition Chart (2005)

Your daily energy use depends on your level of physical activity.

To calculate this, you should multiply the daily basic needs by the appropriate number:

- Sedentary work: 1.4;

- Medium level of physical activity: 1.7;

- High level of physical activity: 2

So, for example, in my case it went like this:

Basic metabolic requirements: 11.6 x 88 + 879 = 1900 kcal

Daily energy use: 1900 kcal x 2 = 3800 kcal, rounded up to 4000 kcal.

And on top of this we have the calorie requirement of the daily extra physical activity.

Cycling at 15km/h burns about 500 kcal/hour.

Cycling 8 hours /day means 8x500 = 4000 kcal.

So during the CBR my required daily calorie intake is: 4000 + 4000 = 8000 kcal.

Based on the specialist literature all this energy has to come in the below proportions:

- 60% carbohydrates = 4800 kcal = 1200g

- 15% proteins = 1200 kcal = 300g

- 25% fat = 2000 kcal = 222g

Based on the above division in my case, 300g of proteins/day means 3.4g for each kg of my body weight. However, this could place a burden on my digestive system so I choose to use high quality whey protein, BCAA and glutamine. This way, protein proportion is decreased to 10% and I can add the remaining 5% to my carbohydrate intake

Recommended water intake is 1 litre/1000 kcal of nutrients, so in my case that amounts to 8 litres. This sounds about right as I ride 8 hours/day and produce 1 litre of perspiration/hour.

I need 50g of carbohydrates/hour to replenish my glycogen stores – a totally manageable amount via my preferred snacks (raisins, peanuts, glucose/dextrose tablets, chocolate and of course my famous, home-made sports drink).  If you do the math, 8 hours of riding means 8 x 50g = 400g of carbohydrates.