title: Evaluating the effects of caffeine and sodium bicarbonate, ingested individually or in combination, and a taste-matched placebo on high-intensity cycling capacity in healthy males.
abstract: This study evaluated the effects of ingesting sodium bicarbonate (NaHCO3) or caffeine individually or in combination on high-intensity cycling capacity. In a counterbalanced, crossover design, 13 healthy, noncycling trained males (age: 21 ± 3 years, height: 178 ± 6 cm, body mass: 76 ± 12 kg, peak power output (Wpeak): 230 ± 34 W, peak oxygen uptake: 46 ± 8 mL·kg(-1)·min(-1)) performed a graded incremental exercise test, 2 familiarisation trials, and 4 experimental trials. Trials consisted of cycling to volitional exhaustion at 100% Wpeak (TLIM) 60 min after ingesting a solution containing either (i) 0.3 g·kg(-1) body mass sodium bicarbonate (BIC), (ii) 5 mg·kg(-1) body mass caffeine plus 0.1 g·kg(-1) body mass sodium chloride (CAF), (iii) 0.3 g·kg(-1) body mass sodium bicarbonate plus 5 mg·kg(-1) body mass caffeine (BIC-CAF), or (iv) 0.1 g·kg(-1) body mass sodium chloride (PLA). Experimental solutions were administered double-blind. Pre-exercise, at the end of exercise, and 5-min postexercise blood pH, base excess, and bicarbonate ion concentration ([HCO3(-)]) were significantly elevated for BIC and BIC-CAF compared with CAF and PLA. TLIM (median; interquartile range) was significantly greater for CAF (399; 350-415 s; P = 0.039; r = 0.6) and BIC-CAF (367; 333-402 s; P = 0.028; r = 0.6) compared with BIC (313: 284-448 s) although not compared with PLA (358; 290-433 s; P = 0.249, r = 0.3 and P = 0.099 and r = 0.5, respectively). There were no differences between PLA and BIC (P = 0.196; r = 0.4) or between CAF and BIC-CAF (P = 0.753; r = 0.1). Relatively large inter- and intra-individual variation was observed when comparing treatments and therefore an individual approach to supplementation appears warranted.
authors.affiliation: a Department of Life Sciences, Sport, Outdoor and Exercise Science, Derby University, Kedleston Road, Derby DE22 1GB, UK.
authors.forename: Matthew F
authors.initials: MF
authors.lastname: Higgins
authors.affiliation: b Department of Applied Sciences and Health, Coventry University, James Starley Building, Cox Street, Coventry CV1 5FB, UK.
authors.forename: Susie
authors.initials: S
authors.lastname: Wilson
authors.affiliation: b Department of Applied Sciences and Health, Coventry University, James Starley Building, Cox Street, Coventry CV1 5FB, UK.
authors.forename: Cameron
authors.initials: C
authors.lastname: Hill
authors.affiliation: b Department of Applied Sciences and Health, Coventry University, James Starley Building, Cox Street, Coventry CV1 5FB, UK.
authors.forename: Mike J
authors.initials: MJ
authors.lastname: Price
authors.affiliation: b Department of Applied Sciences and Health, Coventry University, James Starley Building, Cox Street, Coventry CV1 5FB, UK.
authors.forename: Mike
authors.initials: M
authors.lastname: Duncan
authors.affiliation: b Department of Applied Sciences and Health, Coventry University, James Starley Building, Cox Street, Coventry CV1 5FB, UK.
authors.forename: Jason
authors.initials: J
authors.lastname: Tallis
mesh_terms: D000293:Adolescent; D001642:Bicycling / Q000502:physiology*; D015992:Body Mass Index; D002110:Caffeine / Q000008:administration & dosage*; D002319:Cardiovascular System / Q000187:drug effects / Q000378:metabolism; D018592:Cross-Over Studies; D019587:Dietary Supplements; D004311:Double-Blind Method; D015444:Exercise / Q000502:physiology; D006801:Humans; D006863:Hydrogen-Ion Concentration; D019344:Lactic Acid / Q000097:blood; D008297:Male; D010101:Oxygen Consumption; D010807:Physical Endurance / Q000187:drug effects; D012137:Respiratory System / Q000187:drug effects / Q000378:metabolism; D017693:Sodium Bicarbonate / Q000008:administration & dosage*; D012965:Sodium Chloride / Q000008:administration & dosage; D013649:Taste; D055815:Young Adult
chemical_list: D019344:Lactic Acid; D002110:Caffeine; D012965:Sodium Chloride; D017693:Sodium Bicarbonate
keywords: alcalose; alkalosis; bicarbonate de sodium; caffeine; caféine; cycling; cyclisme; metabolic buffers; sodium bicarbonate; tampons métaboliques