top of page

Fuelling for F45 and CrossFit - Part 3

Part 3: Credible supplements

Throughout Part 1 of ‘Fuelling for F45 and CrossFit’, the focus was on getting the big ticket items sorted first to get the best results from your training.

Part 2 focused more specifically on fuelling before and after F45 and CrossFit training to make sure you can go harder for longer.

Part 3 will give you the ‘icing on the cake’ in terms of what you need to achieve your goals sooner.

There are hundreds of different supplements out there that promise the world and fail to deliver. In fact, some supplements can also be quite dangerous to your health.

Nobody should put anything in their body without weighing the benefits and risks first, especially if the product promises to increase your bench press by 1043%!

Working with a sports dietitian will ensure that you take the most credible supplement(s), using the most appropriate dosing strategies to achieve the best results.

Three supplements backed by robust science, specific to high intensity training, include beta-alanine, caffeine and creatine.


β-alanine is an amino acid found in animal products (such as chicken breast and fish), but can also be made by the body. It is an important amino acid as it is used in the production of a protein called carnosine.

As a consequence of high intensity training, acid by-products form in our muscles. This causes fatigue and impairs performance. Carnosine in our muscles acts as a buffer, mopping up acid by-products, enabling the muscles to train harder for longer.

Research suggests that β-alanine supplementation of 3.2 - 6.4 g / day over a 4-8 week period provides the best outcomes. It is recommended that you take a split dose across the day with meals to improve uptake.

These recommendations are based on pure β-alanine and not on other β-alanine containing supplements like pre-workouts.

Please note, in some individual’s β-alanine may cause temporary skin tingling and/or redness, but this seems to be reduced with split dosing strategies. I’d hate to see what a pre-workout could do to you.


Caffeine occurs naturally in foods, such as coffee, tea and cocoa and has a long history of safe use as a mild stimulant. In terms of high intensity training, research suggests that caffeine may influence the central nervous system (in a good way), leading to reduced perception of fatigue. In other words, you may be able to go harder for longer after taking this supplement.

A dosing strategy of between 1 – 3 mg caffeine per kilogram (for example - 65 kg female x 2 mg caffeine = 130 mg), taken 1 hour before training. A single expresso contains ~ 113 mg of caffeine, whilst a black tea contains ~ 60 mg.

Please note, caffeine intake may increase heart rate, cause anxiety and over-arousal, disturb sleep, and may cause an upset stomach. If you have never consumed caffeine before, you might want to start off on a low dose and build from there.


Found mostly in our skeletal muscles, creatine increases our body’s ability to produce energy rapidly. Many of us acquire creatine naturally through our diets (e.g. meat & fish). Our body can also produce its own creatine.

More concentrated creatine comes in the form of a supplement. Creatine supplementation has been shown to increase muscle stores of phosphocreatine, enabling the muscle to better resynthesise ATP (the body’s fuel currency). This is particularly handy during high intensity training with short recovery periods as it enhances resistance to muscle fatigue so you can train harder for longer. The degree to which this happens varies between individuals, with approximately 1/3 of users not receiving any benefit.

The most effective form of creatine supplement is creatine monohydrate. Protocol consists of both a loading and maintenance phase. There’s two ways to do it:

  • Acute loading + maintenance:

  • 20 - 30 grams creatine monohydrate per day for 5-7 days split over the day (4 – 5 x 5 gram doses)

  • Acute loading should be followed by maintenance of 2 – 5 grams per day

  • Chronic loading: 3 - 5 grams per day for ~28 days

Please note the following about creatine supplementation:

  • Creatine supplementation is enhanced when taken with a generous portion of carbohydrate

  • Muscle creatinephosphate stores remain elevated for 4 – 6 weeks after ceasing supplementation

  • Acute loading is associated with weight gain of 600 – 1000 grams

  • Some reported side effects such as kidney complications in those with pre-existing conditions

  • Anecdotal effects have been reported including muscle cramps and tears, and impaired hydration

I hope you have enjoyed this 3 part series on Fuelling for F45 and CrossFit.

Want more information? Whatever your question, please feel free to get in touch by clicking here.

Featured Posts
Recent Posts
bottom of page