Should you ‘carb-up’ before training? Studies show that all depends on your goals? Here sports scientist Ross Edgley reveals how those pre-workout carbohydrates could improve your performance in the gym, but won’t necessarily help your six-pack.
Firstly it’s important to state carbohydrates are the body’s primary fuel supply. So if you’re goal is to improve your performance, you absolutely need a sufficient supply. Training or competing without them is ‘sports suicide’. Just ask the scientists at Loughborough University who set out to quantify the difference carbohydrate intake made to a runner’s performance. What they found was those who consumed a high carbohydrate diet 7 days before a 30km treadmill time trial were 10% quicker than those who didn’t.
Science also supports the use of pre-workout carbohydrates for those wanting to pack on muscle too. Researchers from the University of Queensland subjected strength athletes to a carbohydrate restricted diet to analyse its effects on performance. After a 2-day carbohydrate restriction program athletes performed three sets of squats with a load of 80% of one repetition maximum. What they found was the carbohydrate restriction program caused a ‘significant reduction in the number of squat repetitions performed’. Basically showing how avoiding carbohydrates pre-workout could directly reduce your muscle building potential in the weights room.
Also if you’re prone to overtraining, surprisingly pre-workout carbohydrates may hold the answer. Scientists from Loma Linda University Medical Center in California set out to test how carbohydrates influenced the immune system and more specifically cytokine concentrations. Cytokines are substances that carry signals between the cells of the immune system and are believed by researchers to be critical to preventing the body becoming ill and run down from too much exercise. What they found was consuming a 6% carbohydrate drink before training positively affected cytokine levels. Concluding pre-workout carbohydrates could help support the body’s immune system during periods of intense exercise.
So in view of all this research, do I personally ‘carb-up’ pre-workout? The answer is no. Since long gone are the days when I used to compete as an international athlete. Now I train for the sheer love of it and so forgo my pre-workout carbs and improved performance in pursuit of a better six-pack, let me explain why. Researchers from the University of Texas, USA discovered eating pre-workout carbohydrates actually slowed the fat burning process during exercise. This is because the ingestion of carbohydrates causes a rise in the hormone insulin which when elevated during training can ‘limit fat oxidisation’. So by not eating any pre-workout, you effectively put your body in a better hormonal state to burn fat.
So in summary if you’re wanting to improve your performance, in just about anything, be sure to ‘carb-up’ pre-workout. But if you’d happily clock a slower 5km time on the treadmill for a better six-pack come beach season, science may support ditching them.
Lose fat with the diet that combines the principles of digestive health and intermittent fasting - Click here to find our more
• M K Ranchordas, P Pattison (2011) ‘Effects of carbohydrate and caffeine co-ingestion on a reliable simulated soccer-specific protocol.’ British Journal Of Sports Medicine, 2011, 45
• M. Doherty and P. M. Smith (2005) ‘Effects of caffeine ingestion on rating of perceived exertion during and after exercise: a meta-analysis.’ Scandinavian Journal of Medicine & Science in Sports, Volume 15, Issue 2, pages 69–78, April 2005
• D. Essig, D. L. Costill and P. J. Van Handel (1980) ‘Effects of Caffeine Ingestion on Utilization of Muscle Glycogen and Lipid During Leg Ergometer Cycling.’ International Journal Of Sports Medicine.
• G.L. Khanna & I. Manna (2004) ‘Supplementary effect of carbohydrate-electrolyte drink on sports performance, lactate removal & cardiovascular response of athletes’ Indian J Med Res 121, May 2005, pp 665-669
• Sanders B, Noakes TD, Dennis SC (2001) ‘Sodium replacement and fluid shifts during prolonged exercise in humans’. European Journal of Applied Physiology; 84 : 419-25.
• Rehrer NJ (2001) ‘Fluid and electrolyte balance in ultra-endurance sport’ Sports Medical; 31 : 701-15.
• Clapp AJ, Bishop PA, Smith JF, Mansfield ER (2000) ‘Effects of carbohydrate-electrolyte content of beverages on voluntary hydration in a simulated industrial environment.’ Am Indus Hyg Assoc J; 61 : 692-9.
• Chryssanthopoulos C, Williams C, Nowitz A (2002) ‘Influence of a carbohydrate-electrolyte solution ingested during running on muscle glycogen utilisation in fed humans.’ Int J Sports Med; 23 : 279-84.
• Fallowfield JL, Williams C, Singh R (1995) ‘ The influence of ingesting a carbohydrate-electrolyte beverage during 4 hours of recovery on subsequent endurance capacity.’ Int J Sports Nutr; 5 : 285-99.
• Bilzon JL, Allsopp AJ, Williams C (2000) ‘Short-term recovery from prolonged constant pace running in a warm environment: the effectiveness of a carbohydrate-electrolyte solution.’ Eur J Appl Physiol; 82 : 305-12.
• Gisolfi CV (1983) ‘Water and electrolyte metabolism during exercise’. In: Fox EL, editor. Nutrient utilization during exercise. Columbus: Ross Laboratories; p. 21-5.
• Nehlsen-Cannarella SL, Fagoaga OR, Nieman DC, Henson DA, Butterworth DE, Schmitt RL, Bailey EM, Warren BJ, Utter A and Davis JM (1985) “Carbohydrate and the cytokine response to 2.5 h of running.” Journal Of Applied Physiology, 1997 May;82(5):1662-7.
• Horowitz JF, Mora-Rodriguez R, Byerley LO and Coyle EF (1997) “Lipolytic suppression following carbohydrate ingestion limits fat oxidation during exercise.” American Journal Of Physiology, 1997 Oct;273(4 Pt 1):E768-75.
• M Leveritt and P. J. Abernethy (1999) “Effects of Carbohydrate Restriction on Strength Performance” Journal of Strength & Conditioning Research, February 1999