title: Cerebrovascular, cardiovascular and strength responses to acute ammonia inhalation.
abstract: OBJECTIVE
  Ammonia is used as a stimulant in strength based sports to increase arousal and offset fatigue however little is known about its physiological and performance effects. The purpose of this study was twofold (1) establish the physiological response to acute ammonia inhalation (2) determine whether the timing of the physiological response corresponds with a performance enhancement, if any.
  
  
  METHODS
  Fifteen healthy males completed two trials. Trial one investigated the beat-to-beat middle cerebral artery blood flow velocity (MCAv), heart rate (HR) and mean arterial pressure (MAP) response to ammonia inhalation. During trial two, participants performed a maximal single mid-thigh pull (MTP) at various time points following ammonia inhalation in a randomised order: MTPs were conducted immediately, 15, 30 and 60 s following ammonia inhalation. A MTP with no ammonia inhalation served as the control. During this trial maximal MTP force, rate of force development (RFD) and electromyography (EMG) activity were recorded.
  
  
  RESULTS
  MCAvmean increased and peaked on average by 6 cm s(-1) (P < 0.001), 9.4 ± 5.5 s following ammonia inhalation. Similarly, HR was increased by 6 ± 11 beats per minute 15 s following ammonia inhalation (P < 0.001). MAP remained unchanged following inhalation (P = 0.51). The use and timing of ammonia inhalation had no effect on maximal force, RFD or EMG (all P > 0.2) compared to control.
  
  
  CONCLUSIONS
  MCAv was elevated despite no increase in MAP occurring; this is indicative of a cerebrovascular vasodilation. Despite the marked cerebrovascular and cardiovascular response to ammonia inhalation no ergogenic effect was observed during the MTP, irrespective of the timing of administration.
authors.affiliation: School of Sport and Exercise, Massey University, Private bag 11 222, Palmerston North, 4442, New Zealand.
authors.forename: Blake G
authors.initials: BG
authors.lastname: Perry
authors.affiliation: Department of Exercise and Sport Science, Universal College of Learning, Palmerston North, New Zealand.
authors.forename: Hayden J
authors.initials: HJ
authors.lastname: Pritchard
authors.affiliation: School of Sport and Exercise, Massey University, Private bag 11 222, Palmerston North, 4442, New Zealand. m.barnes@massey.ac.nz.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Barnes
mesh_terms: D000328:Adult; D000641:Ammonia / Q000008:administration & dosage / Q000494:pharmacology*; D001794:Blood Pressure / Q000187:drug effects*; D000697:Central Nervous System Stimulants / Q000008:administration & dosage / Q000494:pharmacology*; D002560:Cerebrovascular Circulation / Q000187:drug effects*; D015444:Exercise; D006339:Heart Rate / Q000187:drug effects*; D006801:Humans; D001239:Inhalation; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects*
chemical_list: D000697:Central Nervous System Stimulants; D000641:Ammonia
keywords: Ammonia inhalation; Ergogenic aids; Mid-thigh pull; Rate of force development