Effects of combined creatine and sodium bicarbonate supplementation on repeated sprint performance in trained men


Journal Title (Medline/Pubmed accepted abbreviation): J. Strength Cond. Res.
Year: 2013
Volume: 27
Issue: 1
Page Numbers: 252-258

Summary of background and research design:
Background: Creatine and sodium bicarbonate are two popularly used supplements to increase gains in strength from resistance training. Creatine is used to delay fatigue by promoting ATP energy production. Sodium bicarbonate is an alkaline agent and helps to buffer muscle cells against metabolic acids produced during exercise.

Hypothesis: The combination of creatine monohydrate and sodium bicarbonate will increase performance above creatine alone.

Experimental Design: randomized, double-blind, placebo-controlled, cross-over design

Subjects: A total of 13 males that regularly underwent at least 5 hrs of endurance training per week

Treatments: Supplementation occurred for 2 days prior to exercise testing. Daily allotments are listed below. Daily allotments were divided into 4 servings spread out throughout the day. Participants were asked to consume 16 oz. of water with each serving.
1. Placebo- maltodextrin: 20 g + 0.5 g/kg body weight
2. Creatine: 20 g creatine monohydrate + 0.5 g/kg maltodextrin
3. Creatine + sodium bicarbonate: 20 g creatine monohydrate + 0.5 g/kg sodium bicarbonate

Protocol: The participants were first assessed for maximum oxygen capacity (VO2max) and familiarized with the exercise protocol. Each treatment was consumed for two days, and then the exercise protocol was completed the following morning. Three weeks separated each of the 3 trials. On the morning of the exercise test, the participants arrived at the laboratory after an overnight fast. A baseline blood sample was collected for analysis of pH, bicarbonate concentration, and lactate concentration. They warmed up on a stationary bicycle for 5 minutes and then completed 3 × 5 second practice sprints. They then performed 6 × 10 second Wingate sprints at a resistance of 0.075 kg/kg body weight. The participants were allowed a one minute rest at 50 W between sprints. Peak power (in watts), relative peak power (in watts per kg body weight), and fatigue index (in watts per second) were measured. After each sprint, the participants reported feelings of fatigue and gastrointestinal (GI) discomfort, distinguishing between upper (ex. nausea) and lower (ex. flatulence) GI symptoms. Post-workout blood samples were also collected 5 minutes after the sixth sprint.

Summary of research findings:
  • Peak power output was significantly greater with creatine + sodium bicarbonate compared to the placebo (p = 0.03). There was not a statistically significant difference between placebo and creatine or creatine and creatine + sodium bicarbonate.
  • Relative peak power was significantly greater in both the creatine and creatine + sodium bicarbonate treatments compared to the placebo.
  • The rate at which peak power declined with the 6 sprints was less with creatine + sodium bicarbonate than with creatine alone or with the placebo.
  • Average power was significantly greater in creatine + sodium bicarbonate compared to the placebo trial. The creatine trial was not statistically different than either the placebo or creatine + sodium bicarbonate.
  • Sodium bicarbonate supplementation elevated blood bicarbonate concentrations about 12% when measured before exercise. Post-exercise, bicarbonate concentrations were about one-third of pre-exercise concentrations, and there were no differences between treatments.
  • There were no differences between treatments for feelings of fatigue or GI distress. This is important since both creatine and sodium bicarbonate can elicit GI discomfort in some athletes.

Key practice applications: This study showed that only 2 days of supplementation with both creatine and sodium bicarbonate increased the speed at which athletes completed cycling sprints. Both of these supplements are widely used and widely available (another name for sodium bicarbonate is baking soda) and may be an easy and effective addition to an athlete’s daily routine, especially when training consists of high intensity, short duration exercise. It is practically appealing that the supplementation in this study did not occur immediately before the workout, which sometimes upsets athletes’ stomachs during the workout thereby decreasing performance measures. Also to decrease GI distress, one large dose is not necessary; small doses of sodium bicarbonate throughout the day are also effective. Additionally, it is likely that supplementation with creatine, sodium bicarbonate, or both before the workout, or at least the same day as the workout, may have a larger effect since there may be more circulating sodium bicarbonate. In order to minimize GI distress, you can introduce both supplements into your daily regimen gradually.

Limitations:
  • The athletes trained after an overnight fast, which is not typical. It is unknown how these results would change if the athletes performed the exercise after a meal.
  • GI discomfort was not reported during the supplementation, only during exercise. At 0.5 g/kg, a 85 kg athlete (187 lb) would consume 42.5 g/day or 10.6 g/serving. This is a large dose of sodium bicarbonate. Many studies in the literature employ a lower dose of 0.3 g/kg body weight.
  • Sodium bicarbonate was not tested alone. Therefore, it is unknown how the benefits of creatine + sodium bicarbonate compare to sodium bicarbonate alone.
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