Science in Crossfit: Research review: Part 1

Date Posted - April 27, 2017
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Effects of a pre-and post-workout protein-carbohydrate supplement in trained Crossfit

Crossfit has been around for 10 years and has evolved massively within this time, what once seemed just random is now specifically programmed for a desired outcome. With this evolution has come a deeper interest in the science of performance specifically in the sport of Crossfit, previous research from other sports was taken and applied to Crossfit as best it could, but this approach could never fully answer the questions asked by coaches and athletes due to the complex interaction of all the part that make us the sport or Crossfit rather than simply looking at the parts insolation. For example, A study that showed an improvement in a rowing time trial could never be fully applied to improving a workout like ‘Jackie’ because of the other variables involved in that workout.

Fortunately, more and more research is being carried out directly on Crossfit performance, both from a nutritional and strength and conditioning standpoint, which makes the application of the results a little easier to apply, although not without it limitations.

This article will cover a study carried out by Outlaw et al, 2014, which looked at how pre and post workout supplementation would affect performance.

Common belief says that we have some fuel in the tank to use up before a training session, while also provide ergogenic substances that may improve performance by one mechanism or another above and beyond their caloric value, for example, improve buffering capacity of metabolic waste products, improving rate of muscular contractions, allowing the regeneration of high energy compounds within muscle tissue between sets and rounds. Once the session has finished its been widely suggested that we should get some more fuel in the tank to kick start the recovery process, restoring depleted muscle glycogen stores, helping to prevent further muscle breakdown and kick starting the re-building process while ensuring we are fully hydrated. The net effect is improved performance, faster recovery and a greater overall training stimulus over the course of a training cycle to allow the body to adapt to.

Kratos Fuel RXD Tropical Orange

One sure fire way to ensure your protein intake is used efficiently would be to bookend your training session with protein (and or carbs depending on diet set up). This allows the muscles to have a constant supply of available amino acids and has been shown to be a pretty effective at helping with increasing recovery and muscular gains by reducing muscle breakdown and helping muscle building.  Interestingly for us Crossfitters, a recent study looking at timed nutrition for Crossfit athletes was carried out late last year. The study found that consuming a supplement containing amino acids, anti- oxidants and polyphenols pre-training and a second supplement containing carbs, protein (20g protein 40g carbs for women, 40g protein 80g carbs for men) post training for 6 weeks led to improvements in aerobic endurance and anaerobic power as shown by a 38 second improvement in test WOD 1 (500 m row, 40 wall balls, 30 push-ups, 20 box jumps, 10 thrusters for time) and 16 reps more for test WOD 2 (15 minutes to complete an 800 m run “buy in”, followed by a AMRAP of 5 burpees, 10 Kettlebell swings, 15 air squats compared to the subjects that didn’t receive the supplements, while improving fat free mass by 1.67% (which was deemed non-significant by the stats). However it is important to take the results of this study with a pinch of salt and use it to explore timed nutrition for Crossfitters rather than taking the results as fact as the study had a few limitations such as a small sample size, no calorie matched double blind placebo, possible learning effect of the WOD’s for the rests (i.e. better strategy or pacing), all of which can affect the validity of a research study. So although improvements were made we can’t 100% be sure they were as a result of the timed nutrition.

Kratos Blackcurrant Recovery

So in short, it provides clues about how timed nutrition might help Crossfit athletes but doesn’t provide concrete information about the specific nature of how or why. Hopefully further studies will shed new light on this area in the future.

Supplements have their place when performance is the main focus, but these will have little impact on performance outcomes if the following factors aren’t focused on first

  • Total calorie intake
  • Total protein intake
  • Carb intake relative to training volume and goals
  • Overall quality of the diet (vitamins / minerals / fibre / hydration)
  • Training programme / Recovery Protocol (sleep / massage  / stress management)
  • Nutrition time


Outlaw JJ, Wilborn CD, Smith-Ryan AE, Hayward SE, Urbina SL, Taylor LW, Foster CA. Effects of a pre-and post-workout protein-carbohydrate supplement in trained crossfit individuals. Springerplus. 2014 Jul 21;3:369

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