Quantifying State Anxiety Changes Following Outdoor versus Treadmill Runs

Endurance running is useful to humans as both a form of exercise to gain or maintain physical fitness and as a stress or anxiety coping mechanism. The physiological benefits of distance running are well studied, and include increased aerobic capacity, maintenance of skeletal muscle density, and reduced body mass index (Miller et al. 2019; Singh et al. 2022).

Among the distance running community, there are innumerable anecdotal reports that treadmill running does not confer the same psychological benefits as outdoor running. Some research exists that investigates the emotional effects of different exercise environments within the constraints of treadmill running, with results suggesting that nature-based themes promote post-run happiness, even if viewed while running on a treadmill (Yeh et al. 2017).

Only limited studies have investigated the differences in psychological effects of treadmill versus outdoor running. For example, Hooper (2003) reports that runners exhibited more positive perceptions and moods when running outdoors compared to on a treadmill. The current literature does not, however, investigate pre- to post-run state, or “in-the-moment”, anxiety changes nor does it evaluate the comparison of these changes between outdoor and treadmill runs.

Miami University students aged 18-24 who reported a regular running volume ≥120 minutes/week and ability to complete a 20-minute sustained run were recruited.

Prior to a 5-week data collection period, participants completed the Perceived Stress Scale - 10 (PSS-10). Participants were asked to complete 5 treadmill + 5 outdoor runs, distributed evenly throughout the 5-week period. They completed the anxiety subscale of the Hospital Anxiety and Depression Scale (HADS) immediately prior to and following each run to capture SA. All surveys were completed independently and virtually via Qualtrics, and all runs were completed independently by participants.

Differences between post- and pre-run SA were calculated for participants with a minimum of 3 runs of each type. These changes were compared based on run type (outdoor or treadmill). Further, combined SA differences were compared to participants’ PSS-10 scores and mean run distance.

Notes on PSS-10:

• Developed by Cohen et al. (1983)

• Measures the degree to which one perceives events in life as stressful

• 5-pt Likert-type scale (never to very often), 10 Q’s

• 40pts total, higher score indicates greater perceived stress

• Sample Question:

  • In the last month, how often have you felt confident about your ability to handle your personal problems?

Notes on HADS Anxiety Subscale:

• Developed by Zigmond & Snaith (1983)

• Measures in-the-moment “state” anxiety

• 4-pt scale (0 to 3), 7 Q’s

• 21pts total, higher score indicates greater perceived state anxiety

• Sample Questions:

  • I feel tense or “wound up”.

  • I can sit at ease and feel relaxed.

  • I feel restless as if I have to be on the move.

While no statistically significant difference was identified between outdoor vs. treadmill running and pre- to post-run SA, the results of this study justify future investigation of similar hypotheses. 

These data strongly suggest that, in general, endurance runs ≥20 minutes are directly associated with immediate reductions in SA, with greater overall training volume having a potentially greater effect. More conclusive results may direct clinicians in providing specific advice to chronically stressed/frequently anxious patients. 

A literature gap remains regarding the quantifiable psychological benefits of endurance running in different environments. Future studies should implement larger sample sizes, closer observation rather than digital survey format, and pre- and post-run measurement of physiological variables associated with SA.

Cohen, S., Kamarck, T., & Mermelstein, R. (1983). Perceived Stress Scale. PsycTESTS Dataset. https://doi.org/10.1037/t02889-000 

Cohen, S. (1986). Contrasting the hassle scale and the perceived stress scale. American Psychologist, 41, 716-719

Cohen S and Williamson GM (1988). Perceived stress in a probability sample of the United States. In S. Spacapan & S. Oskamp (Eds.), The Social Psychology of Health. Newbury Park, CA: Sage

Cohen, S. and Janicki-Deverts, D. (2012) Who’s Stressed? Distributions of Psychological Stress in the United States in Probability Samples from 1983, 2006, and 2009. Journal of Applied Social Psychology, 42, 1320-1334

Hooper, S.E. (2003). The perception of indoor and outdoor exercise environments and their effect on mood states, heart rate, and running time.

Miller, J. R., Van Hooren, B., Bishop, C., Buckley, J. D., Willy, R. W., & Fuller, J. T. (2019). A Systematic Review and Meta Analysis of Crossover Studies Comparing Physiological, Perceptual and Performance Measures Between Treadmill and Overground Running. Sports Medicine, 49(5), 763–782. https://doi.org/10.1007/s40279-019-01087-9

Singh, G., Kushwah, G., Singh, T., Ramírez-Campillo, R., & Thapa, R. K. (2022). Effects of six weeks outdoor versus treadmill running on physical fitness and body composition in recreationally active young males: a pilot study. PeerJ, 10, e13791. https://doi.org/10.7717/peerj.13791 

Yeh, H.-P., Stone, J., Churchill, S., Brymer, E., & Davids, K. (2017). Physical and Emotional Benefits of Different Exercise Environments Designed for Treadmill Running. International Journal of Environmental Research and Public Health, 14(7), 752. https://doi.org/10.3390/ijerph14070752 

Zigmond, A. S., & Snaith, R. P. (1983). The Hospital Anxiety and Depression Scale. Acta Psychiatrica Scandinavica, 67(6), 361–370. https://doi.org/10.1111/j.1600-0447.1983.tb09716.x 

PSS-10 - Perceived Stress Scale - 10 items; contact information and permission to use: Mapi Research Trust, Lyon, France, https://eprovide.mapi-trust.org 

Prior to the conduction of this study protocol, Expedited (level 2) approval was obtained from the Miami University Institutional Review Board.