Overhaul your diet this autumn

Start optimising your body composition now for the next triathlon season


With the season drawing to a close, it may seem like a strange time to be discussing your racing weight. But now is the perfect point to start thinking about your body composition and any changes you need to make for the next season.


Studies have consistently reported a link between leanness and race performance in long-course racing and other ultra endurance sports. And, although the research for sprint- and Olympic-distance racing is limited, power-to-weight ratio remains a big consideration for the athletes competing in those formats.

Too often these factors are taken together, leading amateur sportspeople and coaches to assume that ‘thinner is better’. But athletes such as Chris McCormack have found there are benefits to gaining weight, especially when going long.

Crucially, there’s also a misconception that top endurance athletes reduce body fat/weight during the race season, a misunderstanding that leads many age-groupers to diet unhelpfully during some of their most intense training, increasing the risk of injury and fatigue.

Elites and age-groupers both aim to optimise their physical condition to aid performance, but the ways they do that might vary significantly. While top athletes only make small adjustments to their physical conditioning through a year, many age-group athletes make far more significant changes. If such changes are needed for you, autumn could be just the time.

Set some targets

As the saying goes: if you don’t know where you’re going, you’ll end up somewhere else. So when it comes to changing your body composition it’s important to ask some key questions to work out what your objective is.

Firstly, what physical change is needed? Are you aiming to lose/gain fat, muscle or both? Those who haven’t trained for a while or are new to triathlon may benefit from losing body fat, while those who’ve transferred from sports like rugby or rowing could lose muscle to become more efficient.

Once you know what you’re trying to do, you need to work out the magnitude of change needed and how to measure it. It’s worth saying here that weight is a very poor indicator of physical condition and is virtually useless at telling you whether you’re progressing towards your aim. Slightly better are body composition scales. These pass a small electric current through your body to assess body composition, but their accuracy is affected by things like hydration, so they can’t be fully trusted either.

Universities often offer body composition testing and measure skin folds on specific sites around your body. Performed correctly, these tests are good, but the total body fat percentage score is of little use.

It’s better to record each measurement and get retested regularly to see precisely where any changes in your body fat percentage have occurred. But with each test costing around £100, a more feasible option for many sportspeople is simply letting your clothing tell you where your physiology is changing.

You can also measure things like waist, calf, thigh, chest and arm circumference each month to build a picture of your changing physique. Take these, together with simple performance tests, to ensure that any physical changes are affecting you in the way you want.

Focus on a race

Which race are you preparing for? Recent research has found that the bike section becomes a more accurate predictor of total race time the longer the triathlon. However, leanness is only related to faster bike times on hillier time-trial courses. Therefore smaller reductions in weight might be needed for flat or shorter races than for longer or hillier events.

Body fat and weight is also not strongly related to swimming performance, particularly in open water where bigger may even be better. It also depends if you’re male or female as research consistently shows that leanness, body shape and fat only relate to overall performance in longer-course racing for men. For women, pacing and quality of training is a better predictor – a fact that should be more widely reported given the incidence of eating disorders in female long-course triathletes.

How long do you have until your target race? In practice, you should spread out desired changes over as long a period as possible. Your best options are to either make consistent dietary changes or weave them into your training plan so that certain weeks are geared towards changing your physique rather than generating fitness.

Plan your nutrition

There are, of course, many nutritional strategies, but two possibilities are to ‘limit in life’ or ‘limit in training’ – in other words, reducing certain nutrients during exercise or every day to achieve a certain goal. For those who want to lose body fat those nutrients might be carbohydrate and saturated fat; for those looking to reduce muscle mass they might be protein and carbohydrate.

How to prioritise your nutrition to your triathlon training

You plan your training, so plan your nutrition too. Don’t just cut calories: work out which nutrients to reduce and continue to eat the things you should – eating nothing is a really bad way to lose weight! We tend to eat our biggest meal in the evening, when we need it least. Everyone knows that restricting what you eat can be tough, so make your life easier by sleeping through the times when you’re hungry.

In terms of training to burn fat, many people avoid the gym and simply cut calories. But this often burns muscle not fat, reducing your metabolic rate and causing increased fat storage. So get to the gym and look to hold on to or build muscle. Longer sessions between 55-75% of your HR max are also effective for burning both fat and muscle, so if you’re looking to reduce your fat percentage make sure you eat enough protein to maintain lean tissue.

The process is much the same for gaining weight. While it’ll probably be in the form of muscle, there may be health and performance benefits to be gained from increasing your body fat if you’re a super-lean athlete. Whatever your goal, forget the ‘off-season’. 2015 starts now!

Top tips

There’s no need to be obsessive when it comes to nutrition but if you’re unsure where to start, Matt Fitzgerald, author of Racing Weight, suggests eating more of the stuff you know is good for you and cutting down on what isn’t. Doing this feels less like a diet and encourages a positive change in behaviour. Stick to this 80% of the time and you won’t go far wrong.

If you want to reduce body fat, 20g of whey or casein protein before bed will help limit muscle loss. Somewhat counter-intuitively, cutting fat appears to reduce fat burning rates. Studies also show that high-fat diets in runners don’t lead to weight gain. Therefore, make sure you only reduce saturated and trans fats. Fats from olive and flaxseed oils are great and should feature in your daily diet.

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(Images: National Trust / MaccaLive / Delly Carr / Janos Schmidt / Ewelina Karbowiak)


What changes are you making to your diet this off season? Let us know in the comments!