Skip Navigation LinksHome > January 2010 - Volume 24 - Issue 1 > Added Protein Maintains Efficacy of a Low-Carbohydrate Sport...
Journal of Strength & Conditioning Research:
doi: 10.1519/JSC.0b013e3181c32e20
Original Research

Added Protein Maintains Efficacy of a Low-Carbohydrate Sports Drink

Martínez-Lagunas, Vanessa; Ding, Zhenping; Bernard, Jeffrey R; Wang, Bei; Ivy, John L

Collapse Box


Martínez-Lagunas, V, Ding, Z, Bernard, JR, Wang, B, and Ivy, JL. Added protein maintains efficacy of a low-carbohydrate sports drink. J Strength Cond Res 24(1): 48-59, 2010-The purpose of the present study was to investigate the aerobic capacity characteristics of an isocaloric carbohydrate (CHO) plus protein (PRO) drink and a low-calorie CHO plus PRO drink against a traditional 6% CHO sports beverage. Twelve male and female trained cyclists exercised on 4 separate occasions at intensities that varied between 55 and 75% V̇o2max for 2.5 hours and then at 80% V̇o2max until fatigued. Supplements (255.4 ± 9.1 mL) were provided every 20 minutes and consisted of a 4.5% carbohydrate plus 1.15% protein complex (CHO/PRO H), a 3% carbohydrate plus 0.75% protein complex (CHO/PRO L), a 6% carbohydrate supplement (CHO), or a placebo (PLA). Time to fatigue at 80% V̇o2max was significantly longer (p < 0.05) during the CHO (26.9 ± 6.1 minutes, mean ± SE), the CHO/PRO H (30.5 ± 5.9 minutes), and the CHO/PRO L (28.9 ± 6.5 minutes) trials compared with the PLA trial (14.7 ± 3.4 minutes), with no significant differences among the CHO, CHO/PRO H, and CHO/PRO L treatments. In general, blood glucose, plasma insulin, and carbohydrate oxidation were elevated above PLA during the CHO, CHO/PRO H, and CHO/PRO L trials, whereas plasma free fatty acids, rating of perceived exertion, and fat oxidation values were lower during the CHO, CHO/PRO H, and CHO/PRO L trials compared with the PLA trial. Only minor differences in blood parameters occurred among the CHO, CHO/PRO H, and CHO/PRO L treatments. In summary, partially substituting PRO for CHO in a sports drink did not enhance aerobic capacity, but substitution was able to occur without loss of efficacy. Thus, adding PRO to a low-calorie CHO sports drink may be an effective strategy to enhance aerobic capacity while limiting carbohydrate and caloric consumption.

© 2010 National Strength and Conditioning Association



Article Tools


Article Level Metrics

Search for Similar Articles
You may search for similar articles that contain these same keywords or you may modify the keyword list to augment your search.