title: Expectancy of ergogenicity from sodium bicarbonate ingestion increases high-intensity cycling capacity.
abstract: This study examined whether expectancy of ergogenicity of a commonly used nutritional supplement (sodium bicarbonate; NaHCO3) influenced subsequent high-intensity cycling capacity. Eight recreationally active males (age, 21 ± 1 years; body mass, 75 ± 8 kg; height, 178 ± 4 cm; WPEAK = 205 ± 22 W) performed a graded incremental test to assess peak power output (WPEAK), one familiarisation trial and two experimental trials. Experimental trials consisted of cycling at 100% WPEAK to volitional exhaustion (TLIM) 60 min after ingesting either a placebo (PLA: 0.1 g·kg(-1) sodium chloride (NaCl), 4 mL·kg(-1) tap water, and 1 mL·kg(-1) squash) or a sham placebo (SHAM: 0.1 g·kg(-1) NaCl, 4 mL·kg(-1) carbonated water, and 1 mL·kg(-1) squash). SHAM aimed to replicate the previously reported symptoms of gut fullness (GF) and abdominal discomfort (AD) associated with NaHCO3 ingestion. Treatments were administered double blind and accompanied by written scripts designed to remain neutral (PLA) or induce expectancy of ergogenicity (SHAM). After SHAM mean TLIM increased by 9.5% compared to PLA (461 ± 148 s versus 421 ± 150 s; P = 0.048, d = 0.3). Ratings of GF and AD were mild but ~1 unit higher post-ingestion for SHAM. After 3 min TLIM overall ratings of perceived exertion were 1.4 ± 1.3 units lower for SHAM compared to PLA (P = 0.020, d = 0.6). There were no differences between treatments for blood lactate, blood glucose, or heart rate. In summary, ergogenicity after NaHCO3 ingestion may be influenced by expectancy, which mediates perception of effort during subsequent exercise. The observed ergogenicity with SHAM did not affect our measures of cardiorespiratory physiology or metabolic flux.
authors: Sport, Outdoor and Exercise Science, Department of Life Sciences, Derby University, Kedleston Road, Derby, DE22 1GB, UK.
authors: Matthew F
authors: MF
authors: Higgins
authors: Sport, Outdoor and Exercise Science, Department of Life Sciences, Derby University, Kedleston Road, Derby, DE22 1GB, UK.
authors: Akbar
authors: A
authors: Shabir
mesh_terms: D001642:Bicycling / Q000502:physiology*; D001786:Blood Glucose / Q000378:metabolism; D015992:Body Mass Index; D001835:Body Weight; D002319:Cardiovascular System / Q000187:drug effects / Q000378:metabolism; D019587:Dietary Supplements; D004311:Double-Blind Method; D015444:Exercise / Q000502:physiology; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D019344:Lactic Acid / Q000097:blood; D008297:Male; D058573:Performance-Enhancing Substances / Q000008:administration & dosage*; 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; D055815:Young Adult
chemical_list: D001786:Blood Glucose; D058573:Performance-Enhancing Substances; D019344:Lactic Acid; D012965:Sodium Chloride; D017693:Sodium Bicarbonate
keywords: RPE; effort perçu; endurance; fatigue; perceived exertion; psychobiologie; psychobiology