To parallel the Olympic Games, I am going to write a series of articles on dietary supplements that may help to improve athletic performance. Several years ago, I used to compete in the sport of bicycle racing. I competed for three years in this sport and was fortunate enough to travel North America to various bicycle races.
The highlight of my bicycling career was placing third in the Canadian National Cycling Championship Road Race (1993) along with winning the Alberta Provincial Pursuit Championships the same year. Well, the thirty hour training weeks, leg shaving, broken bones, and road rash are well behind me, but I still have an interest in fitness and sports.
Reminiscing back to those days, I can certainly recall that this where I developed my interest in nutrition and dietary supplements. Back then, the internet was still in its infancy (Remember those old 14,400 baud modems???) and the only source of reasonably reliable information was pretty much limited to both books and magazines that I used to read with a ferocious appetite. To my recollection, even creatine supplementation wasn’t used at the time and would not be widely marketed until perhaps 1994.
Carbohydrate-Protein Gels for Endurance Exercise
During prolonged exercise, it is estimated that protein contributes approximately 5-15% of total energy demands. Because this contribution is significantly less than carbohydrates, protein has often been ignored as an ingredient in sports beverages for endurance exercise. A recent study published in the Journal of Strength and Conditioning Research (Saunders et al, 2007), highlights the importance of consuming protein during endurance exercise.
The subjects in the study consumed either carbohydrate (CHO) gels or carbohydrate plus protein (CHO+P) gels during two timed cycle trials to volitional exhaustion.
The gels themselves included the following ratio of CHO or P per Kg of the subjects body weight (BW):
- 0.146 g CHO/Kg of BW [malodextrin/fructose]
- 0.0365 g P/Kg of BW
A theoretical 70 Kg subject received the following per 15 minute feed:
- 140 ml of water
- 10.22 g CHO
- 2.56 g P [plus or minus the P]
- Subjects performed 13% longer (p<0.05) in the CHO+P trial compared to the CHO trial.
- Post exercise muscle damage was measured indirectly by assessing plasma CK (creatine kinase) concentrations.
Creatine kinase which is also known as creatine phosphokinase is an enzyme present in your blood that elevates with increasing levels of muscle breakdown. Plasma CK concentrations increased significantly in the CHO trial when comparing pre-exercise to post-exercise levels, but not in the CHO+P trial.
The results of this study suggest that supplementation with both CHO as well as P gels as opposed to simply CHO gels alone, had two important benefits. First, the subjects were able to perform endurance exercise for 13% longer period of time when they consumed the CHO and O gels compared to only consuming the CHO gels. Secondly, the subjects had less evidence of muscle damage following exercise when they consumed the CHO+P gels.
Important! For those who seek to maximize their endurance performance, they may want to consider a sports drink which has both protein as well as carbohydrate present in its ingredients.
- Saunders MJ, Luden ND, Herrick JE. Consumption of an oral carbohydrate-protein gel improves cycling endurance and prevents postexercise muscle damage. J Strength Cond Res. 2007 Aug;21(3):678-84.