Effects of a carbohydrate-, protein-, and ribose-containing repletion drink during 8 weeks of endurance training on aerobic capacity, endurance performance, and body composition


Journal Title (Medline/Pubmed accepted abbreviation): J. Strength Cond. Res..
Year: 2012
Volume: 26
Issue: 8
Page numbers: 2234-2242
Summary of background and research design:
Background: It has been shown that the combination of protein and carbohydrates in a recovery beverage is more effective than carbohydrates alone in replenishing energy stores, specifically glycogen, post-workout.  These beverages may also maximize the gains from a workout.  Ribose is a sugar that is found within the chemical structure of ATP (energy) and has been proposed to increase the rate of glycogen restoration.

Hypothesis: Long term use of a recovery beverage containing protein, ribose, and other carbohydrates will increase aerobic capacity and endurance and improve body composition compared to a beverage with only carbohydrates.

Subjects:  Healthy, physically active men (n = 32), age 23 ± 3 y

Experimental design: randomized, double-blind, parallel groups

Treatments:
Test beverage: maltodextrin, whey protein, dextrose, fructose, ribose, vitamins and minerals, 370 kcal/106 g serving (76 g carbohydrate, 14 g protein, 1.5 g fat)
Control beverage: maltodextrin to equal 370 kg/106 g serving (93 g carbohydrate, 0 g protein, 0 g fat)
Both beverages were adjusted so that they were indistinguishable by taste or appearance.

Protocol: The participants were randomly assigned to one of the test beverages.  For 8 weeks, the cyclists participated in supervised exercise sessions- a one hour cycling bout at 70% of their VO2peak 5 times per week.  They then consumed their assigned beverage immediately after exercise.  Food was then consumed 1 or more hours later.  They reported to the lab on 4 occasions- before the commencement of the test period, after the 3rd week, after the 6th week, and after the 8th and final week.  At the laboratory sessions, the participants were evaluated for body composition using underwater weighing and for aerobic capacity.  Aerobic capacity was assessed on a stationary bicycle.  After a warm-up, the athletes cycled at 70 rpm at 60 W.  The power output increased 30 W every 2 min until the participant could not maintain speed.  Respiratory gases were monitored and VO2peak was also noted.  Two days after the aerobic capacity evaluation, the participants were assessed for fixed power output.  After a warm-up on the stationary bicycle, they rode at 90% of their power output until they could not maintain a speed of 60 rpm.  Time to exhaustion was noted.
Summary of research findings: 
  • On average, participants lost weight, lost body fat, increased VO2max, and increased endurance as measured by time to exhaustion with no differences between groups.
  • Only those that consumed the test beverage lost a statistically significant percentage of body fat between a) the beginning of the study and week 3 and b) week 3 and week 6.

Key practice applications: Regularly consuming a post-workout beverage that contained carbohydrates, protein, ribose, vitamins, and minerals did not improve body composition or aerobic capacity any more than a beverage that had only carbohydrates.  With that said, the data suggested that the beverage with protein, ribose, vitamins, and minerals, improved body composition and performance more quickly at the beginning of the exercise study (first 6 weeks) while the participants that consumed the carbohydrate beverage achieved the same gains but in a longer amount of time.

Key search terms for this article (5-7 terms): protein, ribose, post-workout, recovery, aerobic exercise, glycogen, carbohydrates
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