TY - JOUR
T1 - Belief in caffeine's ergogenic effect on cognitive function and endurance performance: A sham dose-response study
AU - Delang, Nathan
AU - Irwin, Christopher
AU - Cox, Gregory R.
AU - McCartney, Danielle
AU - Desbrow, Ben
PY - 2021/9
Y1 - 2021/9
N2 - This study aimed to determine if belief in caffeine's ergogenic potential influences choice reaction time (CRT) and/or running performance. Twenty-nine healthy individuals (23.7 +/- 5 years, 16 males) completed two trials (one week apart). Before the trials, participants indicated their "belief" in caffeine's ergogenic effects and previous "experience" using caffeine for performance. On arrival, participants randomly received either sham "Low (100mg; LD)" or "High (300mg; HD)" dose caffeine capsules 30-min before commencing the CRT test, followed by a 10km run. Paired samples t-tests determined differences between trials for CRT latency (Ex-Gaussian analysis; mu-, sigma- and tau-) and running performance using the entire cohort and sub-groups exhibiting strong "beliefs"+/-"experience". Sham caffeine dose did not influence CRT (mu-, sigma- and tau-respectively, LD: 400 +/- 53ms vs. HD: 388 +/- 41ms; LD: 35 +/- 18ms vs. HD: 34 +/- 17ms; LD: 50 +/- 24ms vs. HD: 52 +/- 19ms, all p's > 0.05). Neither belief (n = 6), nor belief + experience (n = 4), influenced this effect. Furthermore, caffeine dose did not influence run time (LD: 49.05 +/- 3.75min vs. HD: 49.06 +/- 3.85min, p = 0.979). Belief (n = 9) (LD: 48.93 +/- 3.71min vs. HD: 48.9 +/- 3.52min, p = 0.976), and belief + experience (n = 6) (LD: 48.68 +/- 1.87min vs. HD: 49.55 +/- 1.75min, p = 0.386) didn't influence this effect. A dose-response to sham caffeine ingestion was not evident on cognitive or endurance performance in healthy individuals, regardless of their convictions about caffeine's ergogenicity.
AB - This study aimed to determine if belief in caffeine's ergogenic potential influences choice reaction time (CRT) and/or running performance. Twenty-nine healthy individuals (23.7 +/- 5 years, 16 males) completed two trials (one week apart). Before the trials, participants indicated their "belief" in caffeine's ergogenic effects and previous "experience" using caffeine for performance. On arrival, participants randomly received either sham "Low (100mg; LD)" or "High (300mg; HD)" dose caffeine capsules 30-min before commencing the CRT test, followed by a 10km run. Paired samples t-tests determined differences between trials for CRT latency (Ex-Gaussian analysis; mu-, sigma- and tau-) and running performance using the entire cohort and sub-groups exhibiting strong "beliefs"+/-"experience". Sham caffeine dose did not influence CRT (mu-, sigma- and tau-respectively, LD: 400 +/- 53ms vs. HD: 388 +/- 41ms; LD: 35 +/- 18ms vs. HD: 34 +/- 17ms; LD: 50 +/- 24ms vs. HD: 52 +/- 19ms, all p's > 0.05). Neither belief (n = 6), nor belief + experience (n = 4), influenced this effect. Furthermore, caffeine dose did not influence run time (LD: 49.05 +/- 3.75min vs. HD: 49.06 +/- 3.85min, p = 0.979). Belief (n = 9) (LD: 48.93 +/- 3.71min vs. HD: 48.9 +/- 3.52min, p = 0.976), and belief + experience (n = 6) (LD: 48.68 +/- 1.87min vs. HD: 49.55 +/- 1.75min, p = 0.386) didn't influence this effect. A dose-response to sham caffeine ingestion was not evident on cognitive or endurance performance in healthy individuals, regardless of their convictions about caffeine's ergogenicity.
UR - http://www.scopus.com/inward/record.url?scp=85105005841&partnerID=8YFLogxK
U2 - 10.1002/hup.2792
DO - 10.1002/hup.2792
M3 - Article
SN - 0885-6222
VL - 36
JO - Human Psychopharmacology
JF - Human Psychopharmacology
IS - 5
M1 - e2792
ER -
