Ironman Triathlon Calorie Expenditure

IRONMAN TRIATHLON CALORIE EXPENDITURE

Calories needed during a Triathlon or Ironman

The most detailed & easy way to work out calories used during a triathlon or Ironman on the internet.
How to work out calories expenditure during a Swim Bike Run work out or Triathlon.
SWIM
Swimming requires 0.13-0.16 calories per minute per kilo
How to work out calories expenditure during the Swim Bike Run work out and  your Ironman Triathlon.
SWIM
Swimming requires 0.13-0.16 calories per minute per kilo
Example – Hard swim for 70kg athlete for 60 minutes
So a 60 minute hard swim x 16 calories per minute x kilogram (weight of athlete) = calorie expenditure
So swimming hard at 16 calories per minute x 70kg athlete x 60 (minutes)
16 (calories) x 70k (athlete) x 60 minutes = 672 calories per hour.

BIKE
Cycling requires 0.15 -0.17 calories per minute per kilogram of body weight.
Hard bike 0.17 calorie minute kilogram x 60 (minutes) x 70 KG athlete = 714 calories per hour. However this increases exponentially as the speed increases.

RUN
Running requires 0.10 -0.20 calories per minute of body weight of
Hard run 0.17 calories minute kilogram x 60 (minutes) x 70 KG athlete = 714 calories per hour.

A competitor should aim to consume 35% to 55% of the calories required to complete their Ironman. See below approximate calories for the Swim Bike and Run below.

A typical Ironman finisher will use 8,690 – 10,495 calories to complete an Ironman.

Unable to consume anything during the swim you better make sure you have 1,000 calories race morning for breakfast then aim for 260 – 400 an hour obtained from sports drinks bars gels and foods like fruit during the 180k bike and marathon.

Faster swimmers are more efficient than slower swimmers so can use up fewer calories for the distance unlike cycling faster which requires exponentially much more effort.
An Elite athlete who rides at 17 mph could be training very easy while a good age grouper 65-70 could be at almost race pace at this speed, so speed is relative based on athletes ability.

Please note the calories expenditure for the Ironman Swim Bike Run is only approximate.
This all depends on the size of the triathlete so calorie requirements can vary considerably by up to -/+ 12%.
Consider a 12% variable 6% below or above my estimates for example

We are all different, Ability, Male, Female, Age, Weight, Height, Train differently, have different Lifestyles, Sweat rates vary, different economy levels and we are better suited for hilly or flat courses.
Also we all react differently to temperature some prefer cooler or warmer conditions etc.
You main concern is taking in 35% to 55% of the figures per hour in fluids & foods (Gels bars fruit etc)

These Swim Bike Run calories used during the Ironman is my estimate from information gathered over 20 years from athletes during the Ironman from heart rate data & power meter recordings etc. 

Calories increase considerably per stroke (swim) spin (bike) or stride (run) as the average speed increases.
You will notice however that there can be an optimum speed, just like a car that is most fuel efficient at 90kmph (56 mph) any slower or faster then fuel consumption is greater.
We are obviously not machines but the principle is similar so on the 180k bike the calories increase the longer the athlete takes if the speed is slower than 27.2 kmph.
This can also be true if slower than 4 hours 30 minutes for the marathon.
The athlete may be less efficient or will start to lose form, resulting in extra energy required to keep going than earlier in the competition.

The calories requirements below are based on a 35 year old male who weighs 70kg (154 lbs – 11 stone)

Swimming 3.8km
Estimated finish time 55 minutes -   616 calories
Estimated finish time 60 minutes -   672 calories
Estimated finish time 65 minutes -   716 calories
Estimated finish time 70 minutes –   778 calories
Estimated finish time 75 minutes -   826 calories
Estimated finish time 80 minutes -   882 calories
Estimated finish time 85 minutes -   937 calories
Estimated finish time 90 minutes -   992 calories
Estimated finish time 95 minutes - 1047 calories
Estimated finish time 100 minutes -1102 calories
Estimated finish time 110 minutes -1212 calories
Estimated finish time 120 minutes -1323 calories
Estimated finish time 135 minutes -1465 calories

Cycling 180 km Ironman
The more accurate way to estimate calories cycling is to use the following information.

10 mph (16 kmph)       = 26 calories a mile or 260 calories an hour
11 mph (17.6 kmph)    = 27 calories a mile or 297 calories an hour
12 mph (19.2 kmph)    = 28 calories a mile or 336 calories an hour
13 mph (20.8 kmph)    = 29 calories a mile or 377 calories an hour
14 mph (22.4 kmph)    = 30 calories a mile or 420 calories an hour
15 mph (24 kmph)       = 31 calories a mile or 465 calories an hour
16 mph (24 kmph)       = 32 calories a mile or 512 calories an hour
17 mph (27.2 kmph)    = 34 calories a mile or 578 calories an hour
18 mph 24 kmph)       = 36 calories a mile or 648 calories an hour
19 mph (24 kmph)      = 37 calories a mile or 703 calories an hour
20 mph (32 kmph)      = 38 calories a mile or 760 calories an hour
21 mph (33.6kmph)    = 39 calories a mile or 819 calories an hour
22 mph (35.2 kmph)   = 41 calories a mile or 902 calories an hour
23 mph (36.8 kmph)   = 42 calories a mile or 966 calories an hour
24 mph (38.4 kmph)   = 44 calories a mile or 1056 calories an hour
25 mph (40 kmph)      = 47 calories a mile or 1,175 calories an hour

Estimated finish time 4 hours 30 minutes 40.0 kmph (25 mph) – 5,264 calories
Estimated finish time 4 hours 41 minutes 38.4 kmph (24 mph)  – 4,928 calories
Estimated finish time 4 hours 53 minutes 36.8 kmph (23 mph)  – 4,704 calories
Estimated finish time 5 hours 05 minutes 35.2 kmph (22 mph)  – 4,592 calories
Estimated finish time 5 hours 22 minutes 33.6 kmph (21 mph)  – 4,368 calories
Estimated finish time 5 hours 37 minutes 32.0 kmph (20 mph)  – 4,256 calories
Estimated finish time 5 hours 55 minutes 30.4 kmph (19 mph)  – 4,144 calories
Estimated finish time 6 hours 14 minutes 28.8 kmph (18 mph)  – 4,032 calories
Estimated finish time 6 hours 37 minutes 27.2 kmph (17mph)   – 3,808 calories
Estimated finish time 7 hours                  25.6 kmph (16 mph)  – 3,582 calories
Estimated finish time 7 hours 30 minutes 24.0 kmph (15 mph)  – 3,472 calories
Estimated finish time 8 hours 1 minute   22.4 kmph (14 mph)   – 3,360 calories
Estimated finish time 8 hours 4 minutes   20.8 kmph (13 mph)  – 3,248 calories

This is always your bench mark
There are many variables too many to cover in this article that will alter the amount of calories required to cover 180 km (112 miles).

For example:-
Type of bike (aero tubing makes you efficient not faster), reduced rolling resistance, aerodynamic position on the bike, type of helmet, clothing (tight fitting is better than flapping clothing), position of hydration system (drinks bottles on frame or behind saddle), type of wheels, tyres and tyre pressure, triathlon bars, wind, air temperature, hills, they will all affect the energy required to slice through the air.
Type of foods consumed and when can also play a part during the bike section and affect the performance. Solids when it’s easy and you feel great, more liquids & little & often when it’s harder and your energy levels are lower.

Ironman Marathon 26.2 miles
Estimated finish time 3 hours                     - 2,900 calories
Estimated finish time 3 hours 15 minutes –   3,120 calories
Estimated finish time 3 hours 45 minutes    - 3,000 calories
Estimated finish time 4 hours                    - 2,950 calories
Estimated finish time 4 hours 30 minutes   - 3,100 calories
Estimated finish time 5 hours                     -3,150 calories
Estimated finish time 5 hours 30 minutes    - 3,200 calories
Estimated finish time 6 hours                     -3,250 calories
Estimated finish time 6 hours 30 minutes   - 3,300 calories
Estimated finish time 7 hours                     -3,350 calories
Estimated finish time 7 hours 30 minutes    -3,400 calories
Estimated finish time 8 hours                     -3,450 calories

The above average calorie expenditure is based on an Ironman marathon.
Running efficiency is lost after 180k bike due to tight hamstrings partial dehydration, having to consume calories during the run results in higher energy expenditure than a fresh marathon.
Correct bike set up for the Ironman and keeping an even heart rate below your threshold will dictate your race day running efficiency.
Every triathlete is different faster ironman runners tend to have more economical running style after the bike.

For more detaailed information and video footage click in www.ironmantips.com