The placebo effect is a desirable outcome resulting from a person’s belief and/or learned response to a treatment or situation. 1 Although there is considerable evidence for the effect placebos can have on sport performance, 2 empirical evidence in sport and exercise science has remained largely
Philip Hurst, Lieke Schipof-Godart, Florentina Hettinga, Bart Roelands and Chris Beedie
Christian P. Cheung, Joshua T. Slysz and Jamie F. Burr
. 13 This has been supported by a number of randomized control studies; 14 – 16 however, other evidence suggests that observed benefits are primarily a placebo effect 17 , 18 directly relating to the challenges of masking the sham control. The most common control condition mimics an IPC setup using
Stephen A. Mears, Kathryn Dickinson, Kurt Bergin-Taylor, Reagan Dee, Jack Kay and Lewis J. James
training stimulus. 11 , 12 From a physiological standpoint, despite small decreases in liver glycogen stores overnight, 13 fasted exercise should not impair short-duration performance, and therefore any influences on performance or self-selected intensity may be a result of a placebo effect. The placebo
Michael J. Davies, Bradley Clark, Laura A. Garvican-Lewis, Marijke Welvaert, Christopher J. Gore and Kevin G. Thompson
(placebo effect). Conversely, a negative experience in HYPER-DEC in other trial orders may have induced a nocebo effect that manifested in subsequent performances. 30 However, this is unlikely given no participant indicated awareness of deception nor could they correctly identify the administered gas
Zeynep Hazar Kanik, Seyit Citaker, Canan Yilmaz Demirtas, Neslihan Celik Bukan, Bulent Celik and Gurkan Gunaydin
effects of KT on DOMS over a 72-hour period after an intense exercise protocol. Methods Experimental Design This study was designed as a single blind, randomized, placebo-controlled trial. Independent variables were the 2 conditions: KT and placebo KT. Dependent variables consisted of muscle soreness
David C. Nieman, Courtney L. Goodman, Christopher R. Capps, Zack L. Shue and Robert Arnot
at Appalachian State University. Research Design This study used a double-blind, placebo-controlled, randomized crossover design. Study participants ( N = 15) were randomized to coffee or placebo conditions for two weeks, participated in a 50-km cycling time trial, and then crossed over to the
Cori Sinnott, Hayley M. White, Jennifer W. Cuchna and Bonnie L. Van Lunen
Achilles tendinopathy is a painful condition commonly affecting the general and athletic population. It presents with localized pain, stiffness, and swelling in the midportion of the Achilles tendon. The physical stress placed on the tendon results in microtrauma, which leads to subsequent inflammation and degeneration. While it is not surprising that this condition affects the physically active, nearly one-third of Achilles tendinopathy cases occur in sedentary individuals. Etiology for this condition stems from a change in loading patterns and/or overuse of the tendon, resulting in microscopic tearing and degenerative changes. There are numerous causes contributing to the maladaptive response in these patients, such as mechanical, age-related, genetic, and vascular factors. The treatment for these patients is typically load management and eccentric strengthening of the gastrocnemius–soleus complex. Unfortunately, conservative treatment can lead to surgical intervention in up to 45% of cases. A relatively new phenomenon in the treatment of this condition is the use of autologous blood injections (ABI) and platelet-rich plasma injections (PRPI). This need for a less invasive treatment fostered more investigation into ABI and PRPI to treat these nonresponsive patients. However, the evidence concerning the effectiveness of these treatments in patients with Achilles tendinopathy has not been synthesized.
Focused Clinical Question:
In patients with Achilles tendinopathy, how do variations of ABI and PRPI compared with a placebo and/or eccentric training affect pain and function?
Kirsty A. Fairbairn, Ingrid J.M. Ceelen, C. Murray Skeaff, Claire M. Cameron and Tracy L. Perry
; and the presence of any condition that affects hormone metabolism. The University of Otago Human Ethics Committee approved this study; all participants provided written informed consent prior to participation. Study Design This was a prospective parallel group, double-blind, randomized, placebo
Kevin Laudner and Kyle Thorson
shoulder of the participants was randomly assigned to either the experiment group (n = 21) or the placebo group (n = 21). Randomization was determined by free web-based instrument (Research Randomizer, Social Psychology Network, Middletown, CT). Inclusion criteria included being asymptomatic and no recent
Carl J. Hulston and Asker E. Jeukendrup
The purpose of this study was to investigate the possibility of a placebo effect from carbohydrate (CHO) intake during prolonged exercise. Ten endurance-trained male cyclists performed 3 experimental trials consisting of 120 min of steady-state cycling at 61% VO2max followed by a time trial (TT) lasting approximately 60 min. During exercise participants ingested either plain water (WAT), artificially colored and flavored water (PLA), or a 6% carbohydrate-electrolyte solution (CES). PLA and CES were produced with identical color and taste. To investigate the possibility of a placebo effect from CHO intake, participants were told that both flavored solutions contained CHO and that the purpose of the study was to compare CHO drinks with water. Mean power output during TT was 218 ± 22 W in WAT, 219 ± 17 W in PLA, and 242 ± 27 W in CES. Performance times were 66.35 ± 6.15, 65.94 ± 5.56, and 59.69 ± 2.87 min for WAT, PLA, and CES, respectively. Therefore, CES ingestion enhanced TT performance by 11.3% compared with WAT (p < .05) and 10.6% compared with PLA (p < .05), with no difference between PLA and WAT. In conclusion, during a prolonged test of cycling performance, in which participants were not fully informed of the test conditions, there was no placebo effect when participants believed they had ingested CHO. In contrast, the real effect of CHO intake was a 10.6% improvement in TT cycling performance.