title: Improvements in Cycling but Not Handcycling 10 km Time Trial Performance in Habitual Caffeine Users.
abstract: Caffeine supplementation during whole-/lower-body exercise is well-researched, yet evidence of its effect during upper-body exercise is equivocal. The current study explored the effects of caffeine on cycling/handcycling 10 km time trial (TT) performance in habitual caffeine users. Eleven recreationally trained males (mean (SD) age 24 (4) years, body mass 85.1 (14.6) kg, cycling/handcycling peak oxygen uptake ( V · peak) 42.9 (7.3)/27.6 (5.1) mL∙kg∙min(-1), 160 (168) mg/day caffeine consumption) completed two maximal incremental tests and two familiarization sessions. During four subsequent visits, participants cycled/handcycled for 30 min at 65% mode-specific V · peak (preload) followed by a 10 km TT following the ingestion of 4 mg∙kg(-1) caffeine (CAF) or placebo (PLA). Caffeine significantly improved cycling (2.0 (2.0)%; 16:35 vs. 16:56 min; p = 0.033) but not handcycling (1.8 (3.0)%; 24:10 vs. 24:36 min; p = 0.153) TT performance compared to PLA. The improvement during cycling can be attributed to the increased power output during the first and last 2 km during CAF. Higher blood lactate concentration (Bla) was reported during CAF compared to PLA (p < 0.007) and was evident 5 min post-TT during cycling (11.2 ± 2.6 and 8.8 ± 3.2 mmol/L; p = 0.001) and handcycling (10.6 ± 2.5 and 9.2 ± 2.9 mmol/L; p = 0.006). Lower overall ratings of perceived exertion (RPE) were seen following CAF during the preload (p < 0.05) but not post-TT. Lower peripheral RPE were reported at 20 min during cycling and at 30 min during handcycling, and lower central RPE was seen at 30 min during cycling (p < 0.05). Caffeine improved cycling but not handcycling TT performance. The lack of improvement during handcycling may be due to the smaller active muscle mass, elevated (Bla) and/or participants' training status.
authors.affiliation: School of Sport, Exercise and Health Sciences, Peter Harrison Centre for Disability Sport, Loughborough University, Epinal Way, Loughborough LE113TU, UK. t.s.graham@lboro.ac.uk.
authors.forename: Terri
authors.initials: T
authors.lastname: Graham-Paulson
authors.affiliation: Swiss Paraplegic Centre, Institute of Sport Medicine, Guido A. Z&#228;ch-Strasse, Nottwil 6207, Switzerland. claudio.perret@paraplegie.ch.
authors.forename: Claudio
authors.initials: C
authors.lastname: Perret
authors.affiliation: School of Sport, Exercise and Health Sciences, Peter Harrison Centre for Disability Sport, Loughborough University, Epinal Way, Loughborough LE113TU, UK. v.l.tolfrey@lboro.ac.uk.
authors.forename: Victoria
authors.initials: V
authors.lastname: Goosey-Tolfrey
mesh_terms: D000328:Adult; D054874:Athletic Performance; D001642:Bicycling / Q000145:classification; D015992:Body Mass Index; D002110:Caffeine / Q000008:administration & dosage*; D004311:Double-Blind Method; D015444:Exercise; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D019344:Lactic Acid / Q000097:blood; D008297:Male; D010101:Oxygen Consumption; D010807:Physical Endurance / Q000187:drug effects*; D055815:Young Adult
chemical_list: D019344:Lactic Acid; D002110:Caffeine
keywords: ergogenic; exercise; sport; supplement; upper-body