Effect of acute induced metabolic alkalosis on 800-m racing time

Wilkes, Donna L.; Gledhill, Norman; Smyth, Robert D.

doi:10.1249/00005768-198315040-00004

Cited by 159 publications

(87 citation statements)

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“…In addition, preexercise pH values under alkalosis were elevated above placebo values by 0.08 units (p<0.O1). These acid-base changes in the blood were similar to those reported by other authors using strong doses (O.3g.kg bw) of sodium bicarbonate (Inbar et al, 1983;McCartney et al, 1983;Wilkes et al, 1983;Parry-Billings and MacLaren, 1986). This dose exceeds the threshold dosage of NaHCO 3 necessary to elevate blood bicarbonate (Gao et al, 1988).…”

Section: Discussionsupporting

confidence: 89%

“…In previous studies on human subjects, significant improvements in running performances have been recorded (Wilkes et al, 1983;Goldfinch et al, 1988). However, these studies simply implied from circumstantial evidence that the improvements in performance were the result of the acid-base changes in muscle and blood following the ingestion of bicarbonate solutions.…”

Section: Introductionmentioning

confidence: 99%

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Human muscle metabolism during intermittent maximal exercise

Gaitanos

Williams

Boobis

et al. 1993

Journal of Applied Physiology

756

591

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Eight male subjects volunteered to take part in this study. The exercise protocol consisted of ten 6-s maximal sprints with 30 s of recovery between each sprint on a cycle ergometer. Needle biopsy samples were taken from the vastus lateralis muscle before and after the first sprint and 10 s before and immediately after the tenth sprint. The energy required to sustain the high mean power output (MPO) that was generated over the first 6-s sprint (870.0 +/- 159.2 W) was provided by an equal contribution from phosphocreatine (PCr) degradation and anaerobic glycolysis. Indeed, within the first 6-s bout of maximal exercise PCr concentration had fallen by 57% and muscle lactate concentration had increased to 28.6 mmol/kg dry wt, confirming significant glycolytic activity. However, in the tenth sprint there was no change in muscle lactate concentration even though MPO was reduced only to 73% of that generated in the first sprint. This reduced glycogenolysis occurred despite the high plasma epinephrine concentration of 5.1 +/- 1.5 nmol/l after sprint 9. In face of a considerable reduction in the contribution of anaerobic glycogenolysis to ATP production, it was suggested that, during the last sprint, power output was supported by energy that was mainly derived from PCr degradation and an increased aerobic metabolism.

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Section: Discussionsupporting

confidence: 89%

Section: Introductionmentioning

confidence: 99%

Human muscle metabolism during intermittent maximal exercise

Gaitanos

Williams

Boobis

et al. 1993

Journal of Applied Physiology

756

591

View full text Add to dashboard Cite

show abstract

“…Finally, five studies investigated the effects of alkalosis on the performance time for a given event. Two employed the 400-meter run (15,29), one the 800-meter run (66), another the l-mile row (51), and the fifth the 100-meter swim after four intervals (1 1).…”

Section: Performance Outcomesmentioning

confidence: 99%

Effects of Sodium Bicarbonate Ingestion on Anaerobic Performance: A Meta-Analytic Review

Matson¹,

Tran²

1993

International Journal of Sport Nutrition

130

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Many researchers have investigated the effects of induced metabolic alkalosis, by ingestion of sodium bicarbonate, on anaerobic exercise performance. But the results have been inconsistent and often contradictory. The purpose of this review was to synthesize the varied findings using a meta-analytic approach. Twenty-nine investigations met our inclusion criteria. Results show that NaHCO, ingestion clearly results in a more alkaline extracellular environment. The dosage, however, was only moderately related to the increase in pH and HC0,-. Overall, performance was enhanced but the range of effect sizes was large, -0.12 to 2.87. In studies that measured time to exhaustion, there was a mean 27*20% increase in duration. The treatment effect, however, was only weakly related to the degree of induced alkalosis. But in comparing the 19 studies that showed a positive treatment effect with the 16 that showed no effect, the former were associated with a greater increase in pH following ingestion of a somewhat larger dosage, and a greater decrease in pH with exercise.Key Words: bicarbonate loading, ergogenic aids, anaerobic, meta-analysis When exercise is of a near maximal intensity and lasts longer than approximately 20 to 30 seconds, the energy for this work is derived primarily from anaerobic glycolysis. While allowing for the rapid transfer of energy within the working muscle fibers themselves, the total capacity of this system is limited. Without the benefit of oxidative metabolism to remove hydrogen ions from the cell, there is a progressive increase in the acidity of the intracellular environment, resulting in fatigue and the inability to maintain the exercise intensity.The precise mechanism by which increasing acidosis causes muscular fatigue is not clear, but it has been suggested that the accumulation of hydrogen ions may directly inhibit the contractile process by inhibiting the release of Ca++ from the sarcoplasmic reticulum, as well as by reducing the activity of glycolytic enzymes and by impairing the propagation of neural impulses (23). As exercise progresses, various buffering mechanisms function to sequester hydrogen ions and thus forestall the decrement in blood and muscular pH. Eventually when

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“…Over the decades, many studies have reported the positive effects of sodium bicarbonate supplementation and some other ergogenic aids on blood buffering capacity and exercise performance (Krustrup et al 2015, Wilkes et al 1983. Surprisingly, there are only a few studies that have investigated the impact of diet composition on acid-base status and exercise performance (e.g.…”

Section: Introductionmentioning

confidence: 99%

Dietary acid load and renal function have varying effects on blood acid-base status and exercise performance across age and sex

Hietavala

Stout

Frassetto

et al. 2017

Appl. Physiol. Nutr. Metab.

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Purpose: Diet composition influences acid-base status of the body. This may become more relevant as renal functional capacity declines with aging. We examined the effects of low (LD) versus high dietary acid load (HD) on blood acid-base status and exercise performance.Methods: Participants included 22 adolescents (AD), 33 young adults (YA) and 33 elderly (EL), who followed a 7-day LD and HD in a randomized order. At the end of both diet periods the subjects performed a cycle ergometer test (3x10 min at 35%, 55%, 75%, and (except EL) until exhaustion at 100% of VO 2 max). At the beginning of, and after the diet periods, blood samples were collected at rest and after all workloads. VO 2 , RER and HR were monitored during cycling. Results:In YA and EL, bicarbonate (HCO 3 -) and base excess (BE) decreased over the HD period, and HCO 3 -, BE and pH were lower at rest after HD compared to LD. In YA and EL women, HCO 3 -and BE were lower at submaximal workloads after HD compared to LD. In YA women, the maximal workload was 19 % shorter and maximal VO 2 , RER and HR lower after HD compared to LD. Conclusions:Our data uniquely suggests that better renal function is associated with higher availability of bases, which may diminish exercise-induced acidosis and improve maximal aerobic performance. Differences in glomerular filtration rate between the subject groups likely explains the larger effects of dietary acid load in the elderly compared to younger subjects and in women compared to men.

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Effect of acute induced metabolic alkalosis on 800-m racing time

Cited by 159 publications

References 0 publications

Human muscle metabolism during intermittent maximal exercise

Human muscle metabolism during intermittent maximal exercise

Effects of Sodium Bicarbonate Ingestion on Anaerobic Performance: A Meta-Analytic Review

Dietary acid load and renal function have varying effects on blood acid-base status and exercise performance across age and sex

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