Same Effort, Further Distance: What a New Study Says About Exercising in the Woods

The short version

• In a 2026 crossover trial of 47 healthy adults, people covered about 4.6% more distance in a 30 minute forest session than in an urban one, at the same effort and the same heart rate.
• The bigger differences were psychological. Enjoyment, post-exercise mood and the intention to exercise again were all much higher after the forest session.
• The distance gain was small. The motivation gain was large. That is the part most worth acting on.
• The study was short and the sample was narrow, so treat it as a promising signal, not a rule.

The findings

What the researchers did

A team at Loughborough University in the UK, working with the University of Zurich, recruited 47 healthy adults aged 18 to 31 (31 men and 16 women). Each person did a 30 minute self-paced run or walk twice, four weeks apart: once on a loop in ancient woodland and once on a loop around an industrial estate. The order was randomized and balanced, a design called a counterbalanced crossover trial, so every participant acted as their own comparison. Effort was held constant on purpose. Participants were asked to work at 4 out of 10 on a perceived exertion scale, described in the paper as somewhat hard: comfortable, but requiring some effort. The two loops were matched for length (about 630 m each). The forest loop was actually harder: more elevation change (17.7 m per lap versus 0.7 m) and more uneven, sometimes muddy ground.

What they found

• Distance: about 182 m further in the forest (4.6%). This was statistically significant, but the authors describe the effect as small.
• Effort and heart rate: no meaningful difference. People did more work without feeling it, or showing it, in their heart rate.
• Enjoyment: significantly higher in the forest, with a large effect.
• Mood: mood scores improved after the forest session. After the urban session they showed a slight, non-significant move in the wrong direction.
• Intentions: the gaps in stated intention to repeat the session were very large, both for next week and for the next 12 months.

The forest effect did not depend on age, body mass index, weekly activity level, baseline running performance or whether people said they preferred forests to cities. There was a hint that women's intention to exercise again rose more than men's, but it did not reach statistical significance and the authors caution that route layout may explain part of it.

Why might this happen?

The researchers frame the work within what they call the Environmental Mismatch Hypothesis: the idea that modern industrial settings add stressors our biology evolved without, such as air pollution, noise and artificial light, while reducing contact with natural features. They point to air pollution as one possible contributor, since emissions data suggested the urban site had far higher particulate emissions. But no air quality measurements were taken along the routes, so they describe that explanation as speculative. Psychological factors, such as better mood, may also play a role. The study was not designed to settle the mechanism.

A related finding from earlier this year

The same group reported in June 2026 (American Journal of Biological Anthropology) that 25 healthy adults who spent 90 minutes in woodland lasted about 7.5% longer, roughly 1.1 minutes, on a lab cycling test to exhaustion than after 90 minutes in an urban industrial setting. Oxygen uptake and other cardiorespiratory measures barely differed, and mood stayed better for up to two hours.

What the studies do not tell us

• One session per setting. Neither study followed people over weeks or months.
• Intentions are not behavior. The motivation results are what people said they would do. Intention is a good predictor of behavior, but not a guarantee.
• A narrow group. Participants were 18 to 31, mostly male, 81% East Asian, and almost all already met the WHO minimum for physical activity (44 of 47). The authors say results need replicating in older, less active and more diverse groups.
• Specific comparisons. The settings were an ancient woodland and an industrial estate. The studies did not test parks, tree-lined streets, treadmills or any middle ground.
• Heart rate is a proxy. Similar heart rates do not prove identical energy cost, especially on different terrain.

What it means for you

These are practical takeaways drawn from the findings. They are applications of the research, not claims the researchers made.

1. Use nature to protect consistency, not to chase a personal best. The distance gain was small. The enjoyment and motivation gains were large. For most people, the session you actually do beats the session that is slightly more optimal on paper.

2. Judge outdoor sessions by effort, not pace. Trail loops are hillier and less even than pavement, and the study's forest loop was no exception. Anchoring to perceived effort (the study used 4 out of 10 for moderate work) keeps easy days easy wherever you are.

Keep your easy days easy. The study held effort at 4 out of 10, which the paper describes as somewhat hard, the point where speech starts to break up. That is a moderate effort, firmer than the comfortable-conversation pace that defines a true easy run. If you move your easy runs outdoors, our guide What Zone 2 Actually Means (and Why Your Zone 2 Is Not Your Friend's) shows how to find your own easy ceiling with free checks like the talk test and a heart rate drift test, and why a fixed heart rate number can mislead. It also covers how much of your week should be easy: the studies it reviews point to roughly 70 to 85 percent.

3. Put the session you skip most in a place you like. If one workout keeps slipping, try moving it to a trail, a green park or anywhere that feels good to be. The participants who finished the forest session were far more likely to say they would come back.

4. If you can, spend time in a natural setting before a harder session. The June study links time in woodland beforehand with better endurance. That study used 90 minutes of exposure before a lab test, so treat it as an interesting lead, not a pre-workout rule.

5. Mind the terrain. In the forest condition, the ground was slippery for 15 of the 47 participants. Footwear and a slightly shorter stride are worth it on mud and roots.

No green space nearby? The studies do not say a city workout is a bad one. They suggest that enjoyment matters, and enjoyment can come from many places: a favorite route, good company, a view you look forward to.

How Fit PA can help

Fit PA is built around your goal, whether that is losing weight, getting back into a routine, a 5K, a strength block or a long race. Your AI coach builds a plan around your goal and your week, syncs it to your calendar and your watch, and keeps adapting it as you train.

To put this research to work, tell your coach you want more of your easy sessions outdoors. It can build that into your plan, keep hard and easy days properly spaced, and check in if a session gets missed so one skipped day does not turn into a skipped week.

Want to check that an outdoor easy run really stayed easy? Fit PA shows your heart rate zone distribution over time and a zone comparison for each activity. The Zone 2 guide explains how that fits into finding and re-checking your easy zone.

For more research-backed training guidance, browse the Fit PA articles.

You can start a free trial at app.fit-pa.com.

Sources

• Putland MJ, Bailey SJ, Chrismas BCR, Clemes S, et al. Running wild: Forest running enhances performance, enjoyment, mood, and future exercise intentions. Evolution, Medicine, and Public Health, 2026;14(1):1-14. doi:10.1093/emph/eoag018
• Loughborough University. Want to run further, feel better and stay motivated? Exercise in nature, new study. 5 October 2026. lboro.ac.uk
• Loughborough University. Spending time in nature could boost endurance by 7.5%, new research finds. 3 June 2026. lboro.ac.uk (paper: Outpaced by Industry: Industrial Environments Reduce Endurance, With Implications for Evolutionary Fitness, doi:10.1002/ajpa.70270)

Fit PA is a fitness coaching tool, not a medical device, and does not provide medical advice, diagnosis or treatment. Talk with a qualified professional before changing your training if you have a health condition or concern.