Low and moderate doses of caffeine late in exercise improve performance in trained cyclists

• Published in: Applied physiology, nutrition, and metabolism nutrition, and metabolism, 2016-08, Vol.41 (8), p.850-855
• Main Authors: Talanian, Jason L, Spriet, Lawrence L
• Format: Article
• Language: English
• Subjects: agent ergogène; Analysis; Athletes; Athletic Performance; Bicycling; Blood Glucose - metabolism; Body Mass Index; Caffeine; Caffeine - administration & dosage; Caffeine - blood; contre-la-montre; cycling; cyclisme; Dose-Response Relationship, Drug; Double-Blind Method; elite; Epinephrine - blood; ergogenic aid; exercice physique; Exercise; Fatty Acids, Nonesterified - blood; Female; Health aspects; Heart Rate; Humans; Lactic Acid - blood; Male; metabolism; métabolisme; Oxygen Consumption; Time Factors; time trial; Young Adult; élite
• ISSN: 1715-5312; 1715-5320
• DOI: 10.1139/apnm-2016-0053

The aim of the present study was to assess if low and moderate doses of caffeine delivered in a carbohydrate-electrolyte solution (CES) late in exercise improved time-trial (TT) performance. Fifteen (11 male, 4 female) cyclists (age, 22.5 ± 0.9 years; body mass, 69.3 ± 2.6 kg; peak oxygen consumption, 64.6 ± 1.9 mL·min −1 ·kg −1 ) completed 4 double-blinded randomized trials. Subjects completed 120 min of cycling at ∼60% peak oxygen consumption with 5 interspersed 120-s intervals at ∼82% peak oxygen consumption, immediately followed by 40-s intervals at 50 W. Following 80 min of cycling, subjects either ingested a 6% CES (PL), a CES with 100 mg (low dose, 1.5 ± 0.1 mg·kg body mass −1 ) of caffeine (CAF1), or a CES with 200 mg (moderate dose, 2.9 ± 0.1 mg·kg body mass −1 ) of caffeine (CAF2). Following the 120-min cycling challenge, cyclists completed a 6-kJ·kg body mass −1 TT. There was no difference between respiratory, heart rate, glucose, free fatty acid, body mass, hematocrit, or urine specific gravity measurements between treatments. The CAF2 (26:36 ± 0:22 min:s) TT was completed faster than CAF1 (27:36 ± 0:32 min:s, p < 0.05) and both CAF1 and CAF2 TTs were completed faster than PL (28:41 ± 0:38 min:s, p < 0.05). Blood lactate was similar between trials and rose to a greater extent during the TT (p < 0.05). In summary, both doses of caffeine delivered late in exercise improved TT performance over the PL trial and the moderate dose (CAF2) improved performance to a greater extent than the low dose (CAF1).