Drinks with alkaline negative oxidative reduction potential improve exercise performance in physically active men and women: double-blind, randomized, placebo-controlled, cross-over trial of efficacy and safety


Journal Title (Medline/Pubmed accepted abbreviation): Serb J Sports Sci
Year: 2011
Volume: 5
Number: 3
Page number: 83-89
doi (if applicable):

Summary of background and research design:

Background:A dietary supplement that could buffer against the fatiguing effects of lactic acid and have antioxidant properties to protect muscles from oxidative stress may be of interest to all athletes. Negative oxidation reduction potential (NORP) alkaline water may be such a supplement; however, health benefits have not yet been determined

Hypothesis/Purpose: Acute intake (7 days) of NORP would reduce the rate of blood lactate accumulation during and after exercise, increase exhaustion time and serum buffering capacity, and not increase adverse event incidence.

Subjects: Eighteen healthy athletes between 20 and 30 years of age (mean age, 24.3 ± 4.1 y; weight, 80 kg; body fat, 20%) who were experienced in endurance training (> 2 yr) participated in this study.

Experimental design: Randomized, double-blind, cross-over

Treatments Protocol: Each participant was randomized to receive 1 L/day of either the NORP drink (2 g NORP, 6 g sucrose, 1 to 2 mg sodium) or the control drink (minus NORP) for 1 week before the first exercise session. The following week the opposite drink was consumed. All athletes consumed a standardized diet and followed a similar training program (3 days/wk) before each exercise session. During each exercise session, the drink was self-administered before (30 min), during (every 15 min), and after (up to 45 min) exercising. The exercise session was a treadmill ramp protocol up to the maximal symptom-tolerated level. Gas-exchange data were collected throughout the exercise session. Heart rate was continuously monitored during exercise. Blood samples for total antioxidant capacity and glucose, bicarbonate, and lactate levels were collected before, during, and immediately following exercise, and at 3 and 5 minutes after exercise. Rate of perceived exertion (RPE) were assessed during exercise (every 3 min), immediately following exercise, and 3 minutes after exercise.


Summary of research findings:
  • Time to exhaustion, maximal oxygen uptake [VO2max ], blood glucose levels, and total antioxidant capacity were similar between the 2 drink groups.
  • Serum bicarbonate levels were significantly higher following exercise in the NORP group compared with the control group (31.2 vs 26.5 mmol/L; P < .05).
  • Immediately following exercise, RPE scores were significantly decreased in the NORP group compared with the control group (P < .05).
    • RPE scores during the exercise and 3 minutes after exercise were similar between the 2 drink groups.
  • Heart rate during exercise was significantly lower in the NORP group compared with the control group (P < .05).
  • Blood lactate levels were significantly lower in the NORP group compared with the control group (P < .05).
  • After-exercise levels were similar between the 2 drink groups.
  • No adverse events were reported during the study.

Interpretation of findings/Key practice applications:

The results of this study suggest that NORP alkaline water provides buffering abilities in athletes. Exercise performance could be increased, especially during maximal exercise. Lower heart rate indicates less cardiovascular stress and could be a source for enhanced performance. However, blood volume, heart stroke blood volume, and control of heart rate were not assessed in this study. Antioxidant properties of NORP alkaline water were not observed, although biomarkers of oxidative stress were not measured. In addition, performance indicators such as power output were not measured in this study and time to exhaustion did not improve, so it is unclear if NORP alkaline water is an effective ergogenic aid. Finally, the article provided no information on the composition of the NORP ingredient.

 
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