Document Type : Research Paper


1 Assistant Professor of Motor Behavior, Faculty of Physical Education and Sport Sciences, Kharazmi University, Tehran, Iran

2 MSc of Motor Behavior, Faculty of Physical Education and Sport Sciences, Kharazmi University, Tehran, Iran


The aim of this study was to determine the interactive effect of caffeine and attention focus on the postural stability in subjects with different levels of physical activity. 20 male students were divided into two equal groups (physically active and inactive) by the international physical activity questionnaire. Their postural sways were gathered from a force plate system during two 30-second trials with a 1-minute rest interval with no interventions in the pretest and in internal attention focus (attention to the lower extremity) and external attention focus (attention to a point on the front wall) conditions. On the second day of the experiment, subjects in both groups received 5 mg of caffeine per kg of body weight and the postural stability test was conducted under internal and external attention focus conditions after 30 minutes. The results of ANOVA with repeated measures at α=0.05 showed significant increases in the postural sways of both groups in internal and external conditions. Also, the caffeine intervention significantly increased the postural sways of both groups in internal and external conditions. Furthermore, active subjects showed less postural sways in different conditions than the inactive group. Regardless of the focus of attention, caffeine causes more postural sways in both groups with different levels of physical activity through affecting the sympathetic system and increased muscle contractions and tremor. In future studies, other factors such as individual differences in response to caffeine intake or its effect on tasks along with postural disturbances should be considered.


  1. Duarte M, Sternad D. Complexity of human postural control in young and older adults during prolonged standing. Experimental Brain Research. 2008; 191(3), 265-276.
  2. Haghighi AH, Adyalbaf Moghaddam R, HamediNia M. [The effect of caffeine consumption on substrate metabolism and time to exhaustion during exercise and one hour after exercise in athletic female (In Persian)]. Sport Biosciences. 2014; 24, 11-29.
  3. Varmazyar N, Behpour N. [The Effect of Caffeine Supplementation on Fatigue Index and Blood Pressure of Aerobic and Anaerobic Male Athletes (In Persian)]. Quarterly Journal of Sport Bioscience Researches. 2013; 3(10), 57-66.
  4. Foxe JJ, Morie KP, Laud PJ, Rowson MJ, De Bruin EA, Kelly SP. Assessing the effects of caffeine and theanine on the maintenance of vigilance during a sustained attention task. Neuropharmacology. 2012; 62(7), 2320-2327.
  5. Norager CB, Jensen MB, Madsen MR, Laurberg S. Caffeine improves endurance in 75-yr-old citizens: a randomized, double-blind, placebo-controlled, crossover study. J Appl Physiol (1985) 2005; 99:2302-6.
  6. Lee JW. Effects of caffeine of coffee on fine motor, gross motor and balance in healthy adult male [dissertation]. Daejeon: Chungnam National University; 2007.
  7. Enriquez A, Sklaar J, Viirre E, Chase B. Effects of caffeine on postural stability. Int Tinnitus J. 2009; 15(2), 161-3.
  8. Felipe L, Simões LC, Gonçalves DU, Mancini PC. Evaluation of the caffeine effect in the vestibular test. Brazilian journal of otorhinolaryngology. 2005; 71(6), 758-762.
  9. Vuillerme N, Nafati G. How attentional focus on body sway affects postural control during quiet standing. Psychological research. 2007; 71(2), 192-200.
  10. Wulf, G. Attentional focus and motor learning: a review of 15 years. International Review of Sport and Exercise Psychology. 2013; 6(1), 77-104.
  11. Duncan MJ, Smith M, Hankey J, Bryant E. The effect of caffeine ingestion on coincidence anticipation timing, perceived exertion, and leg pain during submaximal cycling. Fatigue: Biomedicine, Health & Behavior. 2014; 2(1), 14-27.
  12. Ruijter J, Ruiter MB, Snel J. The effects of caffeine on visual selective attention to color: An ERP study. Psychophysiology. 2000; 37(4), 427-439.
  13. Brunyé TT, Mahoney CR, Lieberman HR, Taylor HA. Caffeine modulates attention network function. Brain and cognition. 2010; 72(2), 181-188.
  14. Reilly DS, van Donkelaar P, Saavedra S, Woollacott MH. Interaction between the development of postural control and the executive function of attention. Journal of motor behavior. 2008; 40(2), 90-102.
  15. Deslandes AC, Veiga H, Cagy M, Piedade R, Pompeu F, Ribeiro P. Effects of caffeine on the electrophysiological, cognitive and motor responses of the central nervous system. Brazilian Journal of Medical and Biological Research. 2005; 38(7), 1077-1086.
  16. Smith A. Effects of caffeine in chewing gum on mood and attention. Human Psychopharmacology: Clinical and Experimental. 2009; 24(3), 239-247.
  17. Smith, A. Effects of caffeine on human behavior. Food and chemical toxicology. 2002; 40(9), 1243-1255.
  18. Notarius CF, Morris B, Floras JS. Caffeine prolongs exercise duration in heart failure. Journal of cardiac failure. 2006; 12(3), 220-226.
  19. Liguori A, Robinson JH. Caffeine antagonism of alcohol-induced driving impairment. Drug and alcohol dependence. 2001; 63(2), 123-129.
  20. Kim WS, Choi CK, Yoon SH, Kwon JY. Usual Dose of Caffeine Has a Positive Effect on Somatosensory Related Postural Stability in Hemiparetic Stroke Patients. Annals of rehabilitation medicine. 2014; 38(6), 775-783.
  21. Stoffregen TA, Bardy BG, Bonnet CT, Pagulayan RJ. Postural stabilization of visually guided eye movements. Ecological Psychology. 2006; 18(3), 191-222.
  22. Wulf G, Mercer J, McNevin N, Guadagnoli MA. Reciprocal influences of attentional focus on postural and suprapostural task performance. Journal of motor behavior. 2004; 36(2), 189-199.
  23. Lambrecht SG. Attentional focus on supra-postural tasks affects postural control: Neuromuscular efficiency and sway characteristics. University of Windsor. 2010.
  24. Nadji N, Baniasadi M. Effects of coffee on cognitive and balance performance. Proceedings of the 7th Annual GRASP Symposium, Wichita State University; 2011.
  25. Hagströmer M, Oja P, Sjöström M. The International Physical Activity Questionnaire (IPAQ): a study of concurrent and construct validity. Public health nutrition. 2006; 9(06), 755-762.
  26. Faghihimani Z, Nourian M, Nikkar AH, Farajzadegan Z, Khavariyan N, Ghatrehsamani S, Kelishadi R. Validation of the Child and Adolescent International physical activity questionnaires in Iranian children and adolescents. ARYA Atheroscler. 2010; 5(4), 163-166.
  27. Kelishadi R, Ghatrehsamani S, Hosseini M, Mirmoghtadaee P, Mansouri S, Poursafa P. Barriers to physical activity in a population-based sample of children and adolescents in Isfahan, Iran. International journal of preventive medicine. 2010; 1(2), 131-137.
  28. Kirchner M, Schubert P, Schmidtbleicher D, Haas CT. Evaluation of the temporal structure of postural sway fluctuations based on a comprehensive set of analysis tools. Physica A: Statistical Mechanics and its Applications. 2012; 391(20), 4692-4703.
  29. Woollacott M, Shumway-Cook A. Attention and the control of posture and gait: a review of an emerging area of research. Gait & posture. 2002; 16(1), 1-14.
  30. Wulf G, McNevin NH, Shea CH. The automaticity of complex motor skill learning as a function of attentional focus. Quarterly Journal of Experimental Psychology. 2001; 54A, 1143–1154.
  31. Landers M, Wulf G, Wallmann H, Guadagnoli M. An external focus of attention attenuates balance impairment in patients with Parkinson's disease who have a fall history. Physiotherapy. 2005; 91(3), 152-158.
  32. Wulf G, Landers M, Lewthwaite R, Töllner T. External focus instructions reduce postural instability in individuals with Parkinson disease. Physical therapy. 2009; 89(2), 162-168.
  33. Hanachi P, Kaviani G.[Impact of mini trampoline exercise on dynamic balance in old women (In Persian)]. Bimonthly Journal of Hormozgan University of Medical Sciences. 2010; 14(2), 148-155.
  34. Riley MA, Stoffregen TA, Grocki MJ, Turvey MT. Postural stabilization for the control of touching. Human Movement Science. 1999; 18(6), 795-817.
  35. Stoffregen TA, Pagulayan RJ, Bardy BG, Hettinger LJ. Modulating postural control to facilitate visual performance. Human Movement Science. 2000; 19(2), 203-220.
  36. Balasubramaniam R, Turvey MT. The handedness of postural fluctuations. Human Movement Science. 2000. 19(5), 667-684.
  37. McNevin NH, Wulf G. Attentional focus on supra-postural tasks affects postural control. Human movement science. 2002; 21(2), 187-202.
  38. Directorate C. Opinion of the Scientific Committee on Food on Additional information on “energy” drinks. 2003.
  39. Passer MW, Smith, RE. Psychology: Frontiers and applications. 1st ed. McGraw-Hill. New York; 2001.
  40. Ruwer SL, Rossi AG, Simon LF. Balance in the elderly. Brazilian journal of otorhinolaryngology. 2005; 71(3), 298-303.
  41. Altman RD, Lang AE, Postuma RB. Caffeine in Parkinson's disease: A pilot open‐label, dose‐escalation study. Movement Disorders. 2011; 26(13), 2427-2431.
  42. Postuma RB, Lang AE, Munhoz RP, Charland K, Pelletier A, Moscovich, M, Chuang R. Caffeine for treatment of Parkinson disease: A randomized controlled trial. Neurology. 2012; 79(7), 651-658.
  43. Vuillerme N, Danion F, Marin L, Boyadjian A, Prieur JM, Weise I, Nougier V. The effect of expertise in gymnastics on postural control. Neuroscience letters. 2001; 303(2), 83-86.
  44. Lamoth CJ, van Lummel RC, Beek PJ. Athletic skill level is reflected in body sway: a test case for accelometry in combination with stochastic dynamics. Gait & posture. 2009; 29(4), 546-551.
  45. Smith BD, Gupta U, Gupta BS. (Eds.). Caffeine and activation theory: effects on health and behavior. CRC Press; 2006.