The impact of physical exercise on unconscious thought processes and decision making.

Stef Jeuris

The impact of physical exercise on unconscious thought processes and decision making.

This study deals with the research question: “Is physical activity a potential distracter task for future research in the field of unconscious thought processes?” The discussion consists of three parts, and each of these parts contributes in a specific manner to the argument that results in the answer of the research question.                The first part, which discussed the literature on UTT and physical activity, immediately provides an (indirect) argument for a positive response to the research question. The article ‘Food For Thought? Trust Your Unconscious When Energy Is Low’ suggests that when glucose levels are low, relying on unconscious thought leads to superior decisions than consciously thinking.[1] Given this, while considering that glucose levels drop during physical exercise, it is plausible that the unconscious thought effect increases throughout an acute bout of exercise. If this assumption is accurate, physical exercise could lead to better decision making and improved cognitive performances via unconscious thought processes. The accuracy of this statement can be quite easily tested empirically, using standard empirical experiments from the decision-making literature that deals with physical activity. Participants could be submitted to cognitive tests before, during or after an acute bout of physical exercise. However, there is one important problem that further researchers have to overcome when performing such a study: a sudden change (increase) of blood glucose level disrupts unconscious processes in diabetes patients.[2] The question remains whether this effect is transferable to non-diabetics and if it is also disruptive the other way around (when blood glucose levels drop, for example, during exercise).                The second part discussed the meta-analyses dealing with decision making and physical activity, especially those dealing with the short term effects of acute bouts of exercise. These analyses indicated the ambiguous results of empirical studies that looked at the effect of physical activity on decision making. Those studies who found empirical support for the relation between exercise and cognitive performance – and more specific: for decision making – represent the latest works and thus illustrate that, although quite recently, some consensus was reached regarding the effects of exercise on cognition. So, if decision making is a process that includes both conscious and unconscious processes, and decision making is also affected by physical exercise, then perhaps a link between physical exercise and unconscious processes might not be so improbable.               The latest meta-analysis, conducted by Chang and colleagues in 2012, however, provides some clear conclusions regarding the impact of differing moderators on the effect of physical exercise on cognitive performance. First, with regard to exercise intensity, they showed that the higher the exercise intensity, the longer the beneficial cognitive effects could be observed. Second, they indicated that the initial fitness level was also an important moderator; the cognitive performance of ‘physically fit’ participants improved during exercise, while those who are perceived as ‘unfit’ were negatively affected. Nevertheless, “When cognitive performance was assessed following exercise, positive effects were generally observed for all fitness levels.”[3]                        Chang et al., however, also provided an important nuance of their claims regarding the moderators; they warned for third-order causation, which is a problem in every meta-analysis.[4] Looking at one specific moderator is especially challenging when one is dealing with the very complex processes that are at work during decision making. Should, for example, further research find empirical support for a positive relation between physical exercise and unconscious processes, what would this imply for moderators such as exercise intensity or the initial fitness level? Then the differing effects of physical exercise on cognitive performance during the exercise session (in ‘fit’ and ‘unfit’ participants) might be explained from an entirely different perspective. Whereas the authors have now ascribed this effect to the higher need for resources during exercise of these less fit participants – who therefore had “fewer resources available for cognitive performance”, perhaps this could then be explained in terms of blood glucose levels.[5] The less fit participants’ heart rate would go up faster, lowering their blood glucose levels more quickly, and thus possibly disrupting unconscious processes in this group of participants. Although this last part is highly speculative, evidence for a positive relation between physical exercise and unconscious processes could necessitate some serious reinterpretations of past results.                 Finally, this study looked at some recent publications that deal with decision making and physical exercise. Jacobson and Matthaeus focused on executive functions, including decision making, in both externally-paced, self-paced and non-athletes. Although they failed to find significant support for their hypothesis regarding the impact of sports type on decision making, their hypothesis that athletes would be superior to non-athletes in all executive function tasks was supported by the data.[6] This implies that, even at rest, athletes outperform non-athletes in executive functions such as decision making, problem solving and planning. Finally, Hillman et al. provided a neurological framework for the effect of physical activity on brain functions. They indicated that neuroimaging and neurophysiological research, that looked at the effect of physical activity on the anterior cingulated cortex, suggests “an improvement in task performance in aerobically fit individuals”.[7] Considering that, amongst other cognitive functions, decision making originates in the anterior cingulated cortex, Hillman and colleagues provided a last argument in favor of further research on the link between physical activity, unconscious thought processes and decision making.                                Overall, the result of this review is that the research question can be positively answered. First of all, blood glucose levels drop during exercise, and unconscious thought processes are superior when such levels are low. Second, physical exercise has proved to have a positive impact on decision making. Third, even though physically fit individuals gain more quickly from physical activity (during the exercise session), positive effects were observed for all fitness levels after exercising. Lastly, because Hillman and colleagues provided the neurological proof that physical exercise does have an impact on decision making. When all the above is added up, this should suffice to claim that physical activity is a potential distracter task for future research in the field of unconscious thought processes.

[1] Bos, ‘Food for Thought?’, pp. 124-130.

[2] Ibid., pp. 127.

[3] Chang, ‘The effects of acute exercise’, pp. 96.

[4] Ibid., pp. 96.

[5] Ibid., pp. 96.

[6] Jacobson, ‘Athletics and executive functioning’, pp. 523-525.

[7] Hillman, ‘Be smart’, pp. 80.




Journal articles

Bargh, J. (2011), ‘Unconscious Thought Theory and its discontents: a critique of the critiques’, Social cognition, 29 (6), pp. 629-647.

Bos, M.W., Dijksterhuis, A.J. & Van Baaren, R.B. (2012), ‘Food for Thought? Trust Your Unconscious When Energy Is Low’, Journal of Neuroscience, Psychology, and Economics, 5 (2), pp. 124-130.

Bos, M.W., Dijksterhuis, A.J. & Van Baaren, R.B. (2011), ‘The benefits of “sleeping on things”: Unconscious thought leads to automatic weighting’, Journal of Consumer Psychology, 21, pp. 4-8.

Bush, G., et al. (2002), ‘Dorsal anterior cingulate cortex: A role in reward-based decision making’, PNAS, 99, pp. 523-528.

Brisswalter, J., Collardeau, M. & Rene, A. (2002), ‘Effects of acute physical exercise characteristics on cognitive performance’, Sports Medicine, 32, pp. 555-566.

Chang, Y., et al. (2012), ‘The effects of acute exercise on cognitive performance: A meta-analysis’, Brain Research, 1453, pp. 87-101.

Colcombe, S. & Kramer, A. (2003), ‘Fitness effects on the cognitive function of older adults: A Meta-Analytic Study’, Psychological Science, 14, pp. 125-130.

Dijksterhuis, A.J. (2004), ‘Think Different: The Merits of Unconscious Thought in Preference Development and Decision Making’, Journal of Personality and Social Psychology, 87 (5), pp. 586-598.

Dijksterhuis, A.J. & Nordgren, L. (2006), ‘A Theory of Unconscious Thought’, Perspectives on Psychological Science, 1 (2), pp. 95-109. 

Dijksterhuis, A.J., Bos, M.W., Van der Leij, A. & Van Baaren, R.B. (2009), ‘Predicting Soccer Matches After Unconscious and Conscious Thought as a Function of Expertise’, Psychological Science, 20 (11), pp. 1381-1387.

Dijksterhuis A.J., et al. (2006), ‘Complex choices better made unconsciously?’, Science, 313, pp. 760-761.

Dijksterhuis, A.J., et al. (2014), ‘The Replication Recipe: What makes for a convincing replication?’, Journal of Experimental Social Psychology, 50, pp. 217-224.

Etnier, J. & Chang, Y. (2009), ‘The effect of physical activity on executive function: a brief commentary on definitions, measurement issues and the current state of the literature’, Journal of Sport & Exercise Psychology, 31, pp. 469-483.

Etnier, J., et al. (1997), ‘The influence of physical fitness and exercise upon cognitive functioning: a meta-analysis’, Journal of Sport and Exercise Psychology, 19, pp. 249-277.

Fontana, F., et al. (2009), ‘Influence of Exercise Intensity on the Decision-Making Performance of Experienced and Inexperienced Soccer Players’, Journal of Sport and Exercise Psychology, 31, pp. 135-151.

Gutin, B. & DiGennaro, J. (1968), ‘Effect of a treadmill run to exhaustion on performance of simple addition’, Research Quarterly, 39, pp. 958-964.

Gutin, B. & DiGennaro, J. (1968), ‘Effect of one-minute and five-minute step-ups on performance of simple addition’, Research Quarterly, 39, pp. 81-85.

Hillman, C.H., Erickson, K.I & Kramer, A.F. (2008), ‘Be smart, exercise your heart: exercise effects on brain and cognition’, Nature Reviews Neuroscience, 9, pp. 58-65.

Jacobson, J. & Matthaeus, L., ‘Athletics and executive functioning: How athletic participation and sport type correlate with cognitive performance’, Psychology of Sport and Exercise, 15, pp. 521-527.

Kennerly, S., et al. (2006), ‘Optimal decision making and the anterior cingulate cortex’, Nature Neuroscience, 9, pp. 940-947.

Labourne, K. & Tomporowski, P. (2010), ‘The effect of exercise-induce arousal on cognitive task performance: a meta-regression analysis’, Brain Research, 1341, pp. 12-24.

McMorris T. & Graydon, J. (1996), ‘The effects of exercise on the decision-making performance of experienced an inexperienced soccer players’, Research Quarterly for Exercise and Sport, 67, pp. 109-114.

McMorris, T. & Graydon, J. (1996), ‘Effects of exercise on soccer decision-making tasks of differing complexities’, Journal of Human Movement Studies, 30, pp. 177-193.


McMorris T. & Graydon, J. (2000), ‘The effect of incremental exercise on cognitive performance’, International Journal of Sport Psychology, 31, pp. 66-81.

Newell, B. & Shanks, D. (2015), ‘Unconscious influences on decision making: A critical review’, Behavioral and Brain Sciences, 37, pp. 1-61.

Dijksterhuis A.J. et al., ‘Newell and Shanks approach to psychology is a dead end’, open peer commentary on Newell and Shanks (2015).

Pennington, R. and Hanna, S. (2013), ‘The Acute Effects of Exercise on Cognitive Performances of Older Adults’, Journal of the Arkansas Academy of Science, 67, pp. 109-114.

Pronk, N. & Kottke, T. (2009), ‘Physical activity as a strategic corporate priority to improve worker health and business performance’, Preventive Medicine, 49, pp. 316-321.

Smith, P., Dijksterhuis, A.J. & Wigboldus, D. (2008), ‘Powerful People Make Good Decisions Even When They Consciously Think’, Psychological Science, 19 (12), pp. 1258-1259.

Sofi, F. (2010), ‘Physical activity and risk of cognitive decline: a meta-analysis of prospective studies’, Journal of Internal Medicine, 269, pp. 107-117.

Strick, M., Dijksterhuis, A.J. & Bos, M.W. (2011), ‘A Meta-Analysis on unconscious thought effects’, Social Cognition, 29 (6), pp. 738-762.

Strick, M., et al. (2012), ‘Zen meditation and access to information in the unconscious’, Consciousness and Cognition, 21, pp. 1476-1481.

Tenenbaum, G., et al. (1993), ‘The relationship between cognitive characteristics and decision making’, Canadian Journal of Applied Psychology, 18, pp. 48-62

Tomporowski, P. (2003), ‘Effects of acute bouts of exercise on cognition’, Acta Psychologica, 112, pp. 297-324.

Tomporowski, P. & Ellis, K. (1986), ‘The effects of exercise on cognitive processes: A review, Psychological Bulletin, 99, pp. 338-346.

Tompoworwski, P., Lambourne, K. & Okumura, M. (2011), ‘Physical activity interventions and children’s mental function: An introduction and overview’, Preventive Medicine, 52, pp. 3-9.

Von Thiele Schwarz, U. & Hasson, H. (2011), ‘Employee Self-rated Productivity and Objective Organizational Production Levels’, .Journal of Occupational and Environmental Medicine, 53, pp. 838-844.


Online articles

Proper, K. & Van Mechelen, W. (2008), ‘Effectiveness and economic impact of worksite interventions to promote physical activity and healthy diet’, World Health Organization, Accessed 30/04/15, (accessed 30th April 2015).

Dijksterhuis’ ‘Replication crisis or crisis in replication? A reinterpretation of Shanks et al.’,, (accessed 4th May 2015).

Universiteit of Hogeschool
Master in het Management
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