Nutrition For Ironman Training And Improving Body Composition

This title should really be split into two separate topics as they are quite distinct objectives, but most endurance athletes are so obsessed with their weight that the boundaries get pretty blurred. Firstly, note that here I use the term ‘body composition’ instead of ‘weight’. Although it is our weight that we check and measure, track and compare – it’s not the most  reliable measure of our athletic health or fitness to race. Whilst it’s an undeniable fact that your power-to-weight ratio and Vo2 max will improve with weight-loss, which all other things being equal would give an advantage on a bike course with lots of steep climbing, and almost any run race – there are many other factors to consider. For a start ,everybody knows that muscle is heavier than fat. Your muscles are your engine – a combination of your (glycogen) fuel stores, pistons and chassis. Compromise on these too much and you’re running a reduced spec machine. So it’s body composition that we should focus on: a low proportion of body fat to muscle, not simply less weight. A second, and very important point is that a certain amount of body fat is essential for maintaining your health and energy levels whilst undergoing the extreme and unrelenting stresses of training for an ironman and holding down a full-time job, having a relationship/family and running a household. Eat good food and train, that excess weight (fat) will go – starve yourself and you likely wont get through the process to the start line. 

My outline nutrition advice for ironman training is as follows: eat healthily, eat plenty and stay off the scales, most of the year.  What I mean by “healthily” –  avoid highly processed foods and things that can be eaten straight out of the packet (via the microwave) avoid things who’s packaging either claim to be fat/sugar free, or are loaded with the stuff. Seek out foods which are nutritionally dense versus energy dense (unless you’re eating during/after a training session, or trying to gain weight) and are made up of few, and recognisable, ingredients. Include plenty of bright-coloured, vitamin and antioxidant rich, vegetables in your diet and cook from scratch as much as possible. Don’t deny yourself treats of alcohol, chocolate, puddings from time to time, and don’t go short on calories. I personally follow a diet which restricts carbs to low GI sources (oats, brown rice, plain yogurt, vegetables) before training with fruits and sports bars or bakery produce for training fuel and recovery. My own main meals are focused on fresh green vegetables and protein sources. I drink alcohol at weekends and will have home-made dessert sometimes and some chocolate or a cookie every now and then as a snack if I’m feeling drained and deserving! But most of the time I am not trying to loose weight. I’ve learned that I get less sick, and less tired if i maintain a weight greater than what i’d like to be racing at. As far as I’m concerned, there’s no harm in training a little heavy.

However, as races approach I do succumb to that common desire to lean up (or down!) – for practical reasons of not wishing to cart an extra 2-3 kg of spare tyre through 226km, as well as the aesthetic of having to wear a tight race suit all day. Being lean in the final weeks before a race gives me more confidence about my fitness and over the past 4 years, I’ve been learning what I need to do to achieve this, whilst at the same time undergoing my most strenuous training phases. My methods have varied with the development of my training approach and racing. Remember that becoming great at an endurance sport takes time- several years of developmental phases -and during this long period things will change in your life and your body, so it’s important to have an awareness of how what you eat affects your shape and size as well as your overall health, energy levels and training. I’d recommend a food diary for this – though before going further I’d like to stress that this is NOT for the purpose of weight-watchers style calorie-counting but as a method of keeping records and learning about your own response to what you shove down your throat.

Calorie-counting is a bit of a myth… here’s why: Whilst its pretty clear that restricting calorie consumption to a level below your basal metabolic rate (BMR= the energy requirement of your body to perform it’s automatic functions whilst at rest) will result in depletion of fat stores in overweight people, it’s really a lot more complex than that and the calories in/calories out method used by such rapid weigh loss programmes is flawed for many reasons, especially when applied to athletes. Without going into too much depth, it is important to understand that a) the body is not a 100% efficient b) food ‘fuel’ types vary in how efficiently they are converted to energy and c) the body responds to and treats different ‘fuel’ types in different ways. The ‘fuel types’ that I refer to are Fat, Protein and Carbohydrate. The body’s treatment of these is complicated but my lay-person’s summarization is thus: Fat does not go straight on as stored fat when you eat it. Protein can only be processed in limited amounts. Fat and Protein in combination are essential for cell and muscle repair. Fat is a stable, storable fuel source and can be utilized, inexhaustibly, for low-intensity activities. Carbohydrate is our main fuel for intense activity – it requires the least ‘processing’ and is therefor the body’s preferred fuel source, when available. It is turned into glycogen for immediate use and a limited amount can be stored in our muscles. Excess carbohydrate is converted to a more stable fuel source, fat and stored around the body. It’s pretty damn clever and works brilliantly in a natural environment where food sources are available in the correct proportions to see us through the seasons at a healthy and appropriate body weight. Unfortunately the misconception that eating fat will make you fat, and that high-carbohydrates and reduced-fat foods are healthy choices has resulted in a lot of overweight people, not to mention increases in modern disease. If this sounds hard to believe or comes as a surprise to you then really is worth reading further about this. ( A good place to start is a couple of posts on Stevens blog here and here. )

Anyway, if you are someone who does need to shed a bit of weight, or even just trimming down in your final 4-6 weeks before a key event, then as you can see from those quick facts above, you need to be looking to restrict the amount of excess carbohydrate (CHO) in your system and encourage your body to burn fat for fuel. One method, which certainly works for people with a ‘normal’ level of activity (ie non -triathletes!), is to eliminate CHO entirely. There are many weight loss plans/diets based around this concept which offer a healthy and sustainable way of eating without reducing the size of a single portion or counting a single calorie. Having tried this myself and seen Steven loose a lot of weight by this method too I know it works – even with high volume training if that training is an appropriate (low) intensity. For your off-season base training, or someone in the early stages of their Ironman preparations this is ideal – you should be keeping intensity low and encouraging fat oxidization as your focus on building base fitness and developing fuel efficiency.

However, the issue of convenience aside (you’d be surprised how hard it is to get carb-free meals and snacks when out and about) I find the inclusion of CHO in my own diet to be beneficial as my training starts to include greater intensity. I believe that everyone has a level of carbohydrate that they can eat and maintain a stable percentage of body fat. Whilst this level is different from one individual to the next, it’s also effected by the amount of exercise you do, and to a certain extent the timing of CHO consumption. I started to keep my food diary in order to keep a track of my CHO intake versus requirements – to discover what level of excess carb was ‘allowable’ before I started putting on fat, and what was required to get me up and good to go hard again the next day. A simple food diary might just be descriptive – write down what you eat and when, identifying any high carb foods/meals, your training and notes about how you felt in training and about your body composition or your weight. This will enable you to identify areas where you could improve your diet: it may sound daft but you might not have realized that you’re snacking on crisps or chocolate at 4pm every day, or that you drink a can of coke every 2hrs at your desk, until you start to write these things down. You may begin to see trends and associations – perhaps on days where you’ve skipped breakfast, you generally fail to make it to your evening training session. Or that if you have a high volume carb-based evening meal, you feel bloated and heavy the following day. You could make a separate column for ‘bad food choices’ – ie things that you impulsively bought and ate which you know should definitely NOT be included in your diet. This is a very good qualitative method for defining and refining your personal dietary goals.

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