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The 10 Nutrition Commandments for the Functional Fitness Athlete

1. - Thou shall stay consistent

Like exercise, if you want to see any real change from your diet then you have to be consistent. One quinoa salad won’t make you healthy and likewise, one tub of Ben and Jerry’s ice cream isn’t the end of the world.

By being consistent you can also more easily identify what is working and what is not. This is why I’m a big fan of tracking what you eat. Similar to training, tracking your dietary habits alongside some performance/body comp metrics although may be boring, is an easy way to ensure you keep seeing progress.

Follow the Box Nutrition framework:

- Workout your numbers

- Track progression

- Make necessary changes

- Get results

2. - Thou shall always eat when hungry

Like any sport, adequate energy intake should be the cornerstone of your diet setup and due to its heavy energy demands in both volume (a lot of sessions) and intensity, caloric intake is especially important for the competitive athlete. It’s all well and good eating ‘clean’ or ‘Paleo’ but if you’re not meeting the energy demands of your sport then it’s not just performance that will suffer but also health, recovery and an increased likelihood of getting ill.

What about if weight loss is your goal?

Because of the demands of sports like CrossFit(tm) , it's very easy to under-eat when trying cut weight making it unwise to focus on this as your primary goal. A low EA will only negatively affect performance and health. This is why if body composition is an area that needs improvement then a carefully periodised strategy over the season should be implemented rather than a short-term plan. It makes sense to 'programme body comp goals in the base phase of training or well out of competition to minimise loss of performance' (Nutrition and Athletic performance, 2015), where there should also be an emphasis on preserving muscle mass whilst reducing fat mass. A stronger athlete is a better athlete after all.

3. - Thou shall eat properly around training

It is far more important to look collectively at how much you eat rather than the timing, however correct nutrient timing is still very important for fuelling your workouts, mitigating fatigue, facilitating maximum adaptation to training and to improve recovery.

4. - Thou shall eat your veg

It’s very easy to focus on the ‘exciting’ parts of building your diet and sometimes forget the smaller yet integral part of staying healthy, like eating enough veg. Often overlooked, ensuring you consume enough vitamins and minerals we require in small amounts will help keep your body functioning properly for things like energy, bone health, immunity, recovery from exercise and injury. In most cases, providing you’re eating a well-balanced diet then additional supplementation should not be required and will not lead to an improvement in performance or health.

There are some exceptions where precautions should be taken to ensure adequate micronutrient availability. Athletes, who restrict energy intake, are vegetarian, remove whole food groups or undertake severe weight loss strategies can put themselves at risk where a low energy intake is likely to cause an inadequate amount of vitamins and minerals. Also, due to the heavy demands of competitive fitness, there may be a need for additional micronutrients to help with performance, repair and maintenance in sports like this.

Providing you’re eating a well-balanced nutrient-rich diet, additional supplementation should not be necessary. However, additional supplementation may be warranted. My advice would be to get tested for Vit D and iron and make an informed decision based on this. In the meantime, make a concerted effort to eat the rainbow, although incredibly cheesy something like this will stand you in good stead. Remember, a healthy athlete is a better athlete.

5. - Thou shall sleep.

Sleep is just as important as nutrition and exercise. The foundation for recovery, sleep helps with the revitalisation of both physical and mental function. Being deprived of sleep can have a negative impact on body composition, hunger, hormone regulation, cognitive function, energy levels, risk of illness and injury and lead to a drop in performance. If you can’t get 7-8 hours of sleep daily, consider power naps (aim for 15-20 minutes) when you can.

6. - Thou will buy Tupperware

A lack of preparation is one of the biggest problems I see with clients. It’s not that you need the 12 Tupperware box’s of chicken and veg you see floating around IG, but simply ensuring you don’t get caught short by making a note of when you need to prepare for. I like to map out for the week what I’m going to be cooking, jot down what I need to get in and also keep track of days when I’m going to be out and about. This ensures I don’t have those ‘argh, what shall I have’ moments, or left being stranded at work with nothing to get other than the Boots sandwich and crisps meal deal.

Preparation is arguably the most important step to get right. Those who embrace it as part of their new weekly schedule will ultimately get better results in the gym. Fail to prepare, prepare to fail really does hold true here.

7.- Thou will drink shed loads of water

Obviously yo need to drink plenty of water throughout the day but you should also take note of your drinking around training. Drinking enough water helps with health and performance where only a 2% drop in body weight can significantly hinder cognitive function and exercise capacity, particularly in hot weather. Although there are a lot of individual differences between athletes to maintain euhydration (hydrated), it is recommended you consume around 5-10ml/kg of bodyweight 2-4 hours before exercise.

During training athletes should try and replace fluid lost by sweating with around 0.4- 0.8l/h and colder drinks to help keep core temperature down. There will be individual differences so stay flexible and if you perceive you sweat a lot then increase this.

After training you should try and achieve euhydration by consuming slightly more than any bodyweight lost. So for every 1kg lost in weight, drink around 125ml of fluid. Also, aim to keep foods and liquids with sodium in them to help maintain fluid balance.

8. - Thou will not get bored

One of my peeves is when people say they get bored eating ‘healthy’. Well change it then. It’s this dogmatic belief that healthy food must consist of chicken breasts, broccoli and sweet potato. It doesn’t.

9- Thou will start learning

Following a meal plan blindly will only get you so far. By understanding why you should be eating that much, why you should be eating that food, why you should be eating around workouts will make achieving success far easier. Understanding the why’s gives you the ability to be flexible with your diet and build something that not only works but something that you can stick to.

If you haven’t already, then make sure you get your copy of Fuelling the Functional Athlete, the number 1 sports nutrition book for functional fitness.

Also available on Amazon:

10. - Thou will find help

Sometimes knowledge isn’t enough. Whether it’s an accountability buddy, a coach or group, surround yourself with like-minded people and those sharing a similar goal.


Currell, K. (2016). Performance Nutrition. 1st ed. Crowood.

Moore, D., Robinson, M., Fry, J., Tang, J., Glover, E., Wilkinson, S., Prior, T., Tarnopolsky, M. and Phillips, S. (2008). Ingested protein dose response of muscle and albumin protein synthesis after resistance exercise in young men. American Journal of Clinical Nutrition, 89(1), pp.161-168.

Nutrition and Athletic Performance. (2015). Medicine & Science in Sports & Exercise® and in the Journal of the Academy of Nutrition and Dietetics, and the Canadian Journal of Dietetic Practice and Research., (Position Stand).

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