title: Acute Rhodiola rosea intake can improve endurance exercise performance.
abstract: OBJECTIVE
  The purpose of this study was to investigate the effect of acute and 4-week Rhodiola rosea intake on physical capacity, muscle strength, speed of limb movement, reaction time, and attention.
  
  
  METHODS
  
  
  
  METHODS
  A double blind placebo-controlled randomized study (n= 24) was performed, consisting of 2 sessions (2 days per session). Day 1: One hour after acute Rhodiola rosea intake (R, 200-mg Rhodiola rosea extract containing 3% rosavin + 1% salidroside plus 500 mg starch) or placebo (P, 700 mg starch) speed of limb movement (plate tapping test), aural and visual reaction time, and the ability to sustain attention (Fepsy Vigilance test) were assessed. Day 2: Following the same intake procedure as on day 1, maximal isometric knee-extension torque and endurance exercise capacity were tested. Following a 5-day washout period, the experimental procedure was repeated, with the treatment regimens being switched between groups (session 2).
  
  
  METHODS
  A double blind placebo-controlled study (n = 12) was performed. Subjects underwent sessions 3 and 4, identical to Phase I, separated by a 4-week R/P intake, during which subjects ingested 200 mg R/P per day.
  
  
  RESULTS
  
  
  
  METHODS
  Compared with P, acute R intake in Phase I increased (p <.05) time to exhaustion from 16.8 +/- 0.7 min to 17.2+/- 0.8 min. Accordingly, VO2peak (p <.05) and VCO2peak (p<.05) increased during R compared to P from 50.9 +/- 1.8 ml x min(-1) x kg(- )1 to 52.9 +/- 2.7 ml x min(-10) x kg(-1) (VO2peak) and from 60.0 +/- 2.3 ml x min(-1) x kg(-1) to 63.5+/- 2.7 ml x min(-1) x kg(-1) (VCO2peak). Pulmonary ventilation (p =.07) tended to increase more during R than during P (P: 115.9+/- 7.7 L/min; R: 124.8 +/- 7.7 L/min). All other parameters remained unchanged.
  
  
  METHODS
  Four-week R intake did not alter any of the variables measured.
  
  
  CONCLUSIONS
  Acute Rhodiola rosea intake can improve endurance exercise capacity in young healthy volunteers. This response was not altered by prior daily 4-week Rhodiola intake.
authors.affiliation: Faculty of Physical Education and Physiotherapy in the Exercise Physiology and Biomechanics Laboratory at the Katholieke Universiteit Leuven, Tervuursevest 101, B-3001 Leuven, Belgium.
authors.forename: Katrien
authors.initials: K
authors.lastname: De Bock
authors.forename: Bert O
authors.initials: BO
authors.lastname: Eijnde
authors.forename: Monique
authors.initials: M
authors.lastname: Ramaekers
authors.forename: Peter
authors.initials: P
authors.lastname: Hespel
mesh_terms: D000328:Adult; D018592:Cross-Over Studies; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D010101:Oxygen Consumption / Q000187:drug effects; D010807:Physical Endurance / Q000187:drug effects*; D010936:Plant Extracts / Q000008:administration & dosage*; D029771:Rhodiola / Q000737:chemistry; D013647:Task Performance and Analysis
chemical_list: D010936:Plant Extracts