triathlon training

Getting to Racing Weight for Triathletes


Carrying a couple of extra kilograms of bodyweight a few weeks out from your first major race leaves no time to reduce the deficit in a healthy and performance enhancing way. The fat or obese person can probably just increase their exercise level and hey, the fat count will drop off. However, you are probably a different animal, training hard or at the very least above 'normal' and for the most part eating quite well. So how do you go about hitting your optimal weight? Weight (fat) loss from an athletic perspective cannot just be about nil by mouth as this will limit your performance in training, and anyway 95% of 'crash' diets fail in the first few weeks. Instead you must attack fat loss with an holistic approach with optimum nutrition and exercise intensity. We know that fat loss will only occur when energy output exceeds energy intake, regardless of the diet’s macro nutrient mixture (fad diets that will not work long term).

So, why don’t the diets work?

A prudent dietary approach to weight loss unbalances the energy equation just enough to cause change. Therefore, by reducing energy intake by around 500 kcal below daily energy expenditure will produce greater fat loss in relation to the energy deficit (you must be able to train/ recover) than a more severe energy-restricted diet. It has also been show that to crash diet the body restricts the amount of fat being burnt (which is after all our aim).

So, should you just go out and train as hard as you can, eating as little as possible? It’s so much easier than that, especially for your first two phases of training (base I & base II).

These phases teach the body to utilise its own fat stores for energy production. This can only be done (initially), at a moderate to low intensity (aerobic/ LSD). Once you start exercising hard (breathing hard) your body will predominantly use the energy stored in the muscles (glycogen).

Benefits of harder workouts

The benefit of harder sessions with regards to weight loss is that your metabolic rate will stay higher for longer post hard workouts; however this is again using the calories that are readily available at the time.

Fat/carbohydrate: From a calorific perspective as you know, fat yields much more energy than carbohydrate and will only be burnt in the presents of oxygen (aerobic). This is one of the reasons we really start to use it during longer and longer endurance events (effort has to be moderate). Importantly it’s also why, if you work too hard during endurance events without refueling, you will bonk due to running out of readily available energy (glycogen) and not being able to tap into your abundance of fat stores.

A body's daily calorific requirements are determined by three factors:

  1. Resting metabolic rate (RMR),
  2. Thermogenesis (calories required for heat production)
  3. Physical activity

Water then fat

In a generalized trend, during the first week of a calorie controlled diet around 70% of the weight loss is water. In weeks 2-3 it becomes 70% fat loss, 20% water and 10% protein and finally in week 4 it can be 85% fat loss with around 15% from protein (McArdle, Katch and Katch 2001).

Weight in muscle

As triathletes, if we go from a couple of weeks of pre-winter recovery into winter training increasing our exercise levels, we will inevitably increase our muscle tone. If we were to go through a heavy period of strength training or a power phase the effect could be to increase muscle bulk (this should only be minimal) and thus possibly see increase in weight. This could be seen as detrimental to our performance (decreased economy), however don’t react negatively to muscle tone/ bulk if it is going to increase your performance - check the clock!

The opposite side to the above situation is when you restrict your calorie intake so much that you start to loose fat-free mass and this can lead to a drop off in performance/strength, Again, check the clock/ power meter.

The nitty gritty

So how do we go about calculating the number of calories we need per day? This is a tough one, as most normalized tables take into account your BMI (Body Mass Index), which in my view is a load of cods wallop! For example, a 5ft5 body builder with 6% body fat weighing in at 80kgs would come up as obese on a BMI scale, so as you can see this does not work for athletes.

Another method that can be used provides a couple of 'intensity levels' you have to mark yourself against; 1 being low, 2 is moderate and 3 is heavy. However, 'heavy' could be manual labour... So what about the age-group triathlete who goes to work all day on a building site and still trains 12 hours per week? Or the ironman athlete doing 20-30+ hours of endurance training per week? It's far too generic a method and does not give a good indication of the true work load carried out per day.

So we need to be a little bit more specific; the example below is the method I have used for some time now and it works quite well.

Weight goal for performance Please note, this is just an example to show the figures and not a prescription! The optimum percentage figures for fat in male and female elite triathletes were given as 5-12% and 8-15% respectively by Wilmore and Costill in 1999.

Weight 72.6kg
Relative fat 25% (measured with calipers or underwater weighing is the most effective)
Fat weight 18.2kg (weight x 25%)
Fat free weight 54.4kg (weight – fat weight)
Relative fat goal 18% (= 82% fat-free)
Weight goal 66.3kg (fat-free weight ÷ 81%)
Weight loss goal 6.3kg

Healthy deficit

Athletes should aim to lose no more than 0.5 – 1kg per week, losing more weight could lead to losses in fat-free mass. Once you reach your upper limit of your goal weight you should look for supervision form a professional to help reduce weigh further and this should be done at an even slower rate (less that 0.5kg per week, again not to have a detrimental effect on performance). In order to change your weight by 0.5kg per week you must decrease your intake by 200 – 500 kcal per day.

Holistic approach

You do not have to start counting and measuring out each potion of food like a body builder. If you feel you are over fat (weight), get a professional to measure your body fat percentage (use calipers or underwater weighing), then make some basic changes.

  • Simply eat a well balanced diet
  • Snack on fruit/ veg, health snacks (low GI if not training)
  • Cut down on carbs prior to bed (salad/veg/protein is energy enough)
  • Eat little and often (never eat until you are full or stuffed)
  • Keep blood sugar balanced throughout the day (little and often)
  • Eat as naturally as possible (no hydrogenated fat, E numbers, etc)
  • Cut down on booze (one small glass of wine is 90 calories)
  • Get into good sleep patterns (you only release growth hormone during sleep)
  • De-stress
  • Stay hydrated

As soon as you stop over-eating (as per the majority of the western population), which is what you must have been doing if you are carrying too much fat, give it a bit of time and you will see your fat-weight start to come down.

It still takes discipline not to say “Oh that was a hard bike session, I’ll have some chocolate or other high calorific treat now,” which means you fill yourself up on foods with low nutritional benefit instead of healthy/good stuff. The other killer, if you don’t replenish energy during long rides/ runs and bonk, is that you get back home and gorge yourself on sweet stuff!

Insulin spike

Foods with a high glycemic (GI) index (white rice, pasta, cakes, sweets) are often accompanied by a spike of insulin. The excessive insulin pulls too much glucose from the blood causing fatigue, hunger, and usually additional sugar cravings. This cycle continues throughout the day impeding the use of fats as a fuel and ultimately leading to weight gain. This does not mean all high GI carbohydrates are bad and should be avoided. High glycemic index foods are very beneficial when consumed prior to, during, and following exercise (Thomas W. Nesser, PhD, CSCS).

Look after the nutritional part of your day to day life as this is where you will make a massive difference to your performance long term. The bottom line is that you need to be happy to perform and if not having any treats or crash dieting is not going to make you happy, be sensible and seek professional advice if you feel you need it.

Please keep in mind that I am not an expert on nutrition and these are just my thoughts (with some research) as a coach, on how to get to race weight sensibly. If there are experts out there who are doing things differently I would love to hear about it.

The Cardiac Drift Phenomenon


You may be thinking about your first ultra endurance event*, ironman triathlon, adventure race, Etape du tour or ultra marathon. Amazing, that just off the top of my head I came up with quite a solid list of events, which are designed to test the limits of human endurance! What’s even more amazing is that these events are not just completed by superhuman elites, they are completed by you and your buddy in the office working 40–50 hrs a week and hey, no afternoon snoozing! That’s superhuman. [*Ultra endurance is determined as an event lasting longer than four hours.]

Trial and error

It may not be the smartest way to observe this area of human physiology; however, I first came across the phenomena known as cardiovascular (CV) drift* when I completed my first middle distance tri. Like most, I had worried about completing the whole event first time around, so set myself a target heart rate to work at. During the run section I looked at my HR to find it was higher than I was expecting for the pace I was setting and my perceived exertion. I slowed my running to the HR levels I had set prior to the start of the race, subsequently my mile pace slowed along with my half marathon time. [*A slow but steady increase in heart rate (HR) is witnessed during prolonged endurance exercise at constant work rate for around 3 – 3:30 hours.]

As a coach, I have investigated this CV drift phenomena and although it is not yet fully understood by sports physiologists, their studies have given me a much better understanding as to why my HR monitor lied to me that day.

Don’t listen to the lies

Why will your HR monitor be lying to you? Basically, if you are running at a steady state, say 160bpm at 7:30 min/mile pace for over an hour (up to about three hours), your heart rate will start to ‘drift’ up to, say, 166bpm, while maintaining the same 7:30 run pace. Because you are a disciplined athlete, you look down at your HR monitor and it’s registering the extra number of beats. You then think “I have to stick to my HR pace”, you slow down until you are back to your predicted steady state HR of 160bpm which, in turn, slows your running to 8 min/mile pace (hypothetically) and you never achieve your predicted race finish times.

Tip: Be aware some studies have reported CV drift from 15 – 33 beats per minute but read on to find out how to limit it.

Importantly, if you train with your HR monitor over long distances and stick to your steady state HR parameters, the CV drift will ultimately have a detrimental effect on your long term preparation and you may never reach optimum performance. Understanding why CV drift occurs will help you prepare for racing better, thus achieving your potential.

The big picture

After reading through scientific papers on triathlon performance etc, it is clear that ultra endurance triathlon (ironman) needs further investigation. Therefore, I have also taken into consideration studies conducted with our single disciplined cousins of swimming, cycling and running and will present my findings from across all endurance sports related to triathlon.

CV drift appears to be caused by a progressive decrease in stroke volume (the amount of blood leaving the heart with each contraction), thus an increase in HR is required to maintain cardiac output during endurance events. A number of studies have shown that CV drift is caused by dehydration and reduced fluid/electrolyte replacement. One other factor related to CV drift is blood glucose levels (carbohydrate, once broken down), therefore the evidence is clear that optimal re-fuelling and energy replacement are vital in reducing the effects of the drift.

Reduce your CV drift

To reduce the effects of CV drift you simply have to reduce or, as much as possible, limit the amount of stress you place on your system during competition and training. For example, in an article I'm writing on ironman preparation I talk about gastric emptying* and how the speed of this emptying is determined through a number of different stimuli including; particle size, dietary fibre, meal volume, meal temperature and osmolality. It therefore makes total sense to do as much as we can to speed up this emptying process and we can do this by reducing the stress or energy (blood shifted from working muscles to gut in this case) required in digesting food stuff while competing. Furthermore, this can be limited by taking in/eating smaller amounts (more often) and chewing it for longer. [*This quite simply is the process of getting fuel into our blood stream and to our working muscles.]

Tip: Remember there are enzymes in our saliva which help break down carbohydrate, so chew your bars longer to utilise them.

If you look at the packaging of gels or most energy bars you will see that they require quite a lot of water (around 200ml) to help in digestion. If these levels are not met you are again placing undue stress on your body and could enter into dehydration.

As mentioned above, a further area to be aware of is the hydration and body temperature. As you know when we exercise (especially in heat) we get progressive water loss through sweating. When the body’s core temperature rises it causes a redistribution of blood to the periphery. Again, these actions cause a reaction, as blood is taken from the one place it is needed, the working muscles in cycling and running.

Be aware… if you are completing a half ironman or full ironman race and are spending more than average (slower times) amount of time completing a race, there is a greater possibility of hyponatraemia (an extracellular sodium imbalance) this is where they are basically over drinking or ingesting too much fluid.

Now for a little twist! As standard and middle distance athletes you know that your HR may drift steadily upwards over the first 3 – 4hrs, known as cardiovascular drift. So what happens in Ultraendurance races of 4hrs or more?

It has been shown that over time, intensity declines as a results of substrate shifts (increased fat use relative to carbohydrate) and neuromuscular fatigue by 6 – 7%. This in turn will show a decrease in heart rate leading to a downward cardiovascular drift. Again this process can be limited by correct re-fuelling, hydration and electrolyte homeostasis.

When an athlete is competing for over four hours and in ultra endurance events lasting days, with very limited sleep (adventure racing and Sahara type marathons), neuromuscular fatigue starts to play a much bigger part. This fatigue leaves a lot to be desired with regard to economy of motion and is a far cry from the perfect running patterns of the 100/200m sprinter. Try to hold good form over the latter part of your race.

Tip: Don’t fret if you are not a strong swimmer in ironman triathlon; just remember to be efficient with your energy while swimming (ie don’t panic) as it is only 10% of the overall triathlon time. Moreover, the swimming leg in triathlon has demonstrated a non-significant relationship with overall race performance.

Take drift out of the equation

The only way to know how hard we should be pushing ourselves during the bike section of a triathlon of any distance (but the longer we go, the more important it becomes) is to use a power meter. There are different types available including Powertap, SRM or Ergomo. It really is crazy how many triathletes spend thousands of pounds on bikes/wheels and still do not use power meters. The effect the bike and wheels will have on your performance is minimum, however the return for your pound gained from using and understanding power meters/ power is massive.


I have presented lots of information here, but if I know my audience well, good preparation is part of most multisport/ endurance athletes lives and hopefully you will now have superior preparation. CV drift will occur, but now that you are aware of it and know how to limit it, your actual race times should not be ‘drifting’ away. Just remember to practice your eating/ re-fuelling patterns and try to keep the body temperature down. Basically limit the amount of undue-stress you place on your body. The body is stressed enough just doing the type of distance and races you guys are asking of it, be kind to it when you can.

Further reading

  1. Bompa, T. O., (1994). Theory and Methodology of Training. Iowa: Kendall and Hunt.
  2. Boudet, G., Albuisson, E., Bedu, M., Chamoux, A., (2004). Heart rate running speed relationships during exhaustive bouts in the laboratory. Can J Appl Physiol. 29(6): 731 – 742
  3. Farber, H. W., Schaefer, E. J., Franley, R., Grimaldi, R., Hill, N. S., (1991). The endurance triathlon: metabolic changes after each event and during recovery. Med Sci Sports Exerc. 23(8): 959 – 965.
  4. Farber, H. W., Arbetter, J., Schaefer, E. J., Dallal, G., Grimaldi, R.., Hill, S., Hill, N., (1987). Acute metabolic effects of an endurance triathlon. Annals of Sports Med. 3: 131 – 138.
  5. Gulbin, J. P., Gaffney, T., (1999). Ultraendurance triathlon participation: Typical race preparation of lower level triathletes. The Journal of Sports Medicine and Physical Fitness, 39(1): 12-15.
  6. Larsen, P. B., Rhodes, E. C., (2001). Factors affecting performance in an Ultraendurance triathlon. Sports Medicine, 31(3): 195 – 209.
  7. Larsen, P. B., Rhodes, E. C., Langill, R. H., (2000). The effects of 3000m-swimming on subsequent 3-h cycling performance; implications for ultrendurance triathletes. Eur J Appl Physiol. 83(1): 28-33.
  8. McArdle, W. D., Katch, F. I., and Katch, V. L. (2001). Exercise Physiology, Energy, Nutrition, and Human Performance. USA: Lippincott Williams and Wilkins.
  9. O’Tool, M. L., Douglas, P. S., (1995). Applied physiology of triathlon. Sports Medicine, 19(4): 251-267.
  10. O’Tool, M. L., Douglas, P. S., Hillier, W. D., (1998). Use of heart rate monitors by endurance athletes: Lessons from triathletes. J Sports Med Phys Fitness. 38(3): 181 – 187.