Uphill gait transitions matched energetic crossover in trained runners

Uphill running
Trail running
Running economy

Thomas Solomon, PhD

7 September 2026

Knowing when to switch from running to walking can matter on sustained climbs. This study tested whether trained runners naturally changed gait near the point where walking and running required similar amounts of energy.

Reference: Finiel et al. Energetic cost of locomotion closely aligns with the preferred uphill walk–run transition at constant vertical speed in runners. European Journal of Applied Physiology (2026) DOI: https://doi.org/10.1007/s00421-026-06363-x. PMID: 42530641. PubMed link: https://pubmed.ncbi.nlm.nih.gov/42530641/.

Study snapshot

A quick, practical summary for runners and coaches.

Quick answer

This laboratory study tested uphill walking and running in 17 trained male distance runners across 6 visits. The runners tended to switch gait near the point where walking and running required similar amounts of energy. The finding is useful for steep climbing, but it doesn’t establish a universal walk-run threshold.

Key takeaways

The runners’ preferred uphill gait transition closely matched the energetic crossover between walking and running.
Heart rate, ventilationThe total amount of air you breathe in or out in one minute. It equals breaths per minute multiplied by the amount of air per breath., and the measured mechanical variables did not align as closely with the transition.
The findings support individualising uphill gait choices rather than treating 1 gradient as a universal walking threshold.

How confident should we be?

Evidence confidence: Moderate

The researchers used detailed physiological and biomechanical measurements in well-trained runners, and the findings broadly fit earlier research. Confidence is limited by the small male-only sample, short laboratory trials, and testing at just 1 vertical climbing speed.

Bottom line

For steep uphill running, walking isn’t automatically the slower or less efficient option. This study suggests that trained runners may naturally switch gait near a useful energetic crossover, but it doesn't tell every runner exactly when they should start walking.

Read the deep dive below to get a practical interpretation, the wider evidence, some actionable decisions, my thoughts, my rating of perceived scientific enjoyment, and the full study details (research question, study design, participants, methods, data integrity, results, and the strengths & limitations).

The deep dive

The details behind the headline result, including the practical meaning, full findings, limitations, and my interpretation.

Practical meaning

What does this research mean for runners and coaches?

The study is most relevant to trail and mountain runners tackling sustained climbs. It suggests that energetic demand may help explain where trained runners prefer to switch between walking and running when the rate of ascent is held constant. That doesn’t mean there is 1 magic speed or gradient for everyone.

For runners

If your races include long, steep climbs, it makes sense to be comfortable with both uphill running and purposeful walking.

That is a practical interpretation rather than something this study directly tested. The researchers did not examine whether practising walking improves race performance, saves energy later in an ultra, or delays fatigue.

What the study does suggest is that your natural gait preference may contain useful information. At a vertical speed of 800 metres per hour, the runners switched close to the estimated point where walking and running had similar energetic demands.

So practise both gaits on race-relevant climbs and pay attention to where each feels sustainable. Just don’t programme 7.3 degrees into your watch as the sacred boundary between running and walking.

For coaches

The study supports considering individual walk-run responses rather than prescribing the same gradient threshold to every athlete.

One sensible interpretation is to expose trail and mountain runners to both walking and running during uphill training, particularly around the climbing intensities they expect to race at. The study did not test whether that training strategy improves performance, though.

Heart rate also shouldn’t be treated as a precise gait-switch signal. Under these conditions, the heart-rate crossover occurred at a noticeably faster speed than the runners’ preferred transition.

Evidence in context

What does the wider evidence say?

Earlier research suggests that runners often switch from walking to running before running becomes the energetically cheaper gait, although the 2 transition speeds appear to converge on steeper slopes. (Minetti et al. 1994) In trained mountain runners, the preferred transition remained slower than the energetic optimum at gradients of 5 and 10 degrees but converged with it at 15 degrees; heart rate did not reliably predict the energetic transition for individuals. (Brill et al. 2021)

How this study fits: This study refines rather than overturns that evidence. By holding vertical climbing speed constant, it found much closer agreement between preferred and energetic transitions, suggesting that the testing protocol may partly explain differences between earlier studies.

Read the full Veohtu deep dive article: Train to resist fatigue

Practical decision

Should runners change anything?

Maybe. If you race on steep trails or mountains, being competent at both uphill running and purposeful walking seems sensible. This is practical interpretation rather than evidence that a specific walk-run training strategy improves performance.

Consider this if

Your races contain sustained steep climbs.
You currently treat walking as something that only happens once running has fallen apart.
You want to experiment with gait choice at race-relevant climbing intensities.

Do not overreact if

Most of your running is on roads or gentle gradients.
Your climbing speeds differ substantially from those tested.
You were hoping for a universal gradient where Science™ tells everyone to start walking.

A sensible next step

Practise both gaits on familiar climbs and learn where switching feels sustainable while maintaining a useful climbing speed. Treat the laboratory result as a clue, not a commandment.

TIP: Never make any major changes to your training or lifestyle habits based on the findings of one study, especially if the study is small or provides low-quality evidence. Check whether other trials confirm the findings. If there is a meta-analysisA meta-analysis quantifies the overall effect size of a treatment by compiling effect sizes from all known studies of that treatment. on the topic, look at the effect sizeA standardised measure of the magnitude of an effect of an intervention. Unlike p-values, effect sizes show the size of the effect and how meaningful it might be. Common effect size measures include standardised mean difference (SMD), Cohen’s d, Hedges’ g, eta-squared, and correlation coefficients., the variability between studies, and the quality of evidenceCertainty of evidence tells us how confident we are that the published results accurately reflect the true effect. It’s based on factors like study design, risk of bias, consistency, directness, precision, and publication bias. High certainty means that the current evidence is so strong and consistent that future studies are unlikely to change conclusions. Whereas, low certainty means more doubt and less confidence, and that future studies could easily change current conclusions..

Expert interpretation

My thoughts

I like this study because it asks a properly practical question with an interesting experimental twist.

Most previous uphill experiments held the gradient constant. That means running faster also means gaining elevation faster. Here, the researchers instead held the vertical speed at 800 metres per hour and changed treadmill speed and gradient together. This controlled the climbing requirement in a different way, although it did not separate the independent effects of speed and gradient.

Under those conditions, the preferred gait transition sat very close to the energetic crossover (the point where walking and running cost about the same amount of energy for the same uphill climbing rate; or, in simple terms: the speed where walking stopped being the cheaper energy cost option and running took over). That's interesting. It also makes biological sense without proving that energy minimisation actually caused the runners to switch.

The practical usefulness is more modest. We have 17 trained men completing short treadmill bouts at 1 fairly demanding climbing rate. That's some distance from hour 8 of a mountain ultra, when your quads have submitted their notice and the next switchback appears to have been designed by a Bond villain.

So I wouldn't change a training plan dramatically. I would, however, take uphill walking seriously as a skill and be curious about where an individual runner naturally prefers to change gait.

The next question is the fun one: does the same energetic relationship survive after several hours of accumulated fatigue?

My Rating of Perceived scientific Enjoyment

RPsE: 7/10

I experienced moderate scientific enjoyment because the study used a thoughtful repeated-measures design, detailed measurements, and transparent reporting to answer a useful trail-running question. The small male-only sample, single climbing speed, and controlled laboratory setting keep it just outside the upper reaches of nerdvana.

Read on for further details about the methods, results, data integrity, strengths, and limitations.

Research question

What did the researchers ask?

The authors aimed to identify which physiological and mechanical measurements best aligned with the speed at which trained runners naturally switched between walking and running uphill.

They specifically examined whether the preferred transition occurred near the crossover between walking and running for energetic cost, oxygen cost, metabolic power, heart rate, ventilation, mechanical work, and basic movement patterns.

Study design

What type of study was this?

This was a controlled repeated-measures laboratory study.

The same runners completed multiple walking and running conditions, which allowed the researchers to compare the 2 gaits within individuals. The order of the experimental conditions was randomisedRandomization means assigning people to different parts of a study (e.g., groups in a randomised controlled trial) by chance, not by choice. This helps make the groups similar at the start and reduces bias, so any differences you see are more likely due to the treatment, not background differences. In a crossover study, randomization usually decides the order in which each person gets the treatments (for example, Treatment A first then B, or B first then A). This way, order effects—like learning, fatigue, or simple time passing—are less likely to skew the results..

This design can show whether different measurements align with the preferred gait transition under the conditions tested. It cannot establish that any 1 measurement, including energetic cost, caused the runners to switch gait.

Participants

Who took part?

The study included 17 male long-distance runners. The participants were aged 25 plus or minus 4 years.

They were well trained: eligibility required the runners to be capable of completing 10 km in less than 38 minutes. The researchers excluded people with medical conditions identified by the Physical Activity Readiness Questionnaire that could affect the study outcomes or athlete health.

Methods

What did the researchers do?

Who? 17 trained male distance runners

What? Uphill walking and running at a fixed vertical speed

How long? 6 visits over 3 to 4 weeks

The participants completed 6 laboratory visits over 3 to 4 weeks.

During the first visit, the researchers measured each runner’s preferred transition speed on an incline treadmill. The runners completed both a walk-to-run test and a run-to-walk test, and the researchers averaged the 2 transition speeds.

Crucially, vertical climbing speed remained fixed at 800 metres per hour. As treadmill speed increased, the gradient became shallower. This kept the rate of elevation gain roughly constant while speed and gradient changed together.

Across later visits, the runners completed randomised 6-minute walking and running conditions. Walking speeds ranged from 0.56 to 2.50 metres per second. Running speeds ranged from 0.56 to 3.89 metres per second.

The researchers measured oxygen use, energy expenditure, ventilation, and heart rate. They averaged the physiological measurements over the final minute of each 6-minute condition.

During the final visit, the participants also completed 30-second trials for movement analysis. A 3-dimensional motion-capture system measured variables including step length, step frequency, and the mechanical work involved in moving the body and limbs.

For each outcome, the researchers fitted mathematical curves to each participant’s walking and running data. Where those curves crossed, they estimated an optimal transition speed for that variable. They then compared these estimated crossovers with the runners’ preferred transition speed.

Data integrity check

Do the numbers add up?

No obvious integrity concerns

I didn’t spot any obvious numerical red flags. The main crossover speeds, confidence intervalsA measure of uncertainty used in Frequentist statistics. The 95% confidence interval is a plausible range of values within which the true value (e.g., the true treatment effect) would be found 95% of the time if the data were repeatedly collected in different samples of people. If this range of values (the confidence interval) crosses zero, there is little confidence that the average value is the true effect. If the confidence interval does not cross zero, we can be confident that the average value is the true effect., and statistical significanceEvidence that a result is unlikely to be due to chance under a “no effect” model (or null hypothesis). Statistical significance is often judged by a p-value below 0.05 to flag that “something” is going on, but not how big or important that “something” is. One statistically significant result doesn’t mean proof; replication is needed. And, a statistically significant result doesn’t necessarily indicate clinical significance. conclusions agree across the text and figures, and the physiological values look plausible for trained runners. Small differences in reported slope values appear consistent with normal rounding. The paper does not report a protocol pre-registrationPre-registration is when a detailed description of a study plan is deposited in an open-access repository before collecting the study data. It promotes transparency and accountability and boosts research integrity. Without preregistration, it is easier for scientists to change outcomes after seeing the data, selectively report “exciting” results, or run many analyses and only show the ones that work, which can introduce bias and weaken the trustworthiness of the findings. or prespecified analysis plan, so I couldn’t check whether the published analyses differed from an earlier plan.

Main findings

What did the study find?

Energetic crossover Closely matched preferred transition

Heart rate & ventilation Crossovers occurred later

Mechanical variables Did not align as closely

The energetic measurements aligned surprisingly closely with when the runners preferred to change gait.

The average preferred transition occurred at 1.76 metres per second, or about 6.3 kilometres per hour, while climbing vertically at 800 metres per hour. This corresponded to an incline of about 7.2 to 7.3 degrees.

The estimated oxygen-cost crossover occurred at 1.80 metres per second. The metabolic-power crossover occurred at 1.79 metres per second, and the energy-cost-of-transport crossover also occurred at around 1.79 metres per second.

The differences between these energetic crossovers and the preferred transition were small and not statistically significant. In plain English, the runners tended to change gait near the estimated point where walking and running imposed similar energetic demands under this particular climbing protocol.

Heart rate did not align as closely. Its crossover occurred at 1.95 metres per second, around 0.19 metres per second faster than the preferred transition. This difference was statistically significant.

Ventilation showed a similar mismatch. Its crossover occurred at 1.89 metres per second, around 0.13 metres per second faster than the preferred transition, also a statistically significant difference.

Internal mechanical work crossed at about 1.90 metres per second and differed significantly from the preferred transition. External mechanical work, total mechanical work, step frequency, and step length did not produce a crossover within the tested range.

These results make the energetic measures the closest-aligned variables investigated here. They do not demonstrate that minimising energy expenditure was the sole reason the runners changed gait.

The authors concluded that, when vertical speed was held constant at 800 metres per hour, the preferred walk-run transition aligned more closely with energetic criteria than with heart-rate, ventilation, or mechanical-work crossovers.

What helps my confidence in the findings?

The strengths

The researchers studied trained distance runners, making the experiment particularly relevant to competitive uphill running.
Each participant completed both walking and running conditions, allowing useful within-runner comparisons.
The researchers randomised the allocation and order of the experimental conditions across visits.
The study combined detailed metabolic, cardiorespiratory, and 3-dimensional biomechanical measurements.
Holding vertical speed constant tested the question differently from earlier fixed-gradient studies and controlled the climbing requirement in a useful way.

What limits my confidence in the findings?

The limitations

The study included only 17 runners, and the authors did not report a sample-size or statistical-power calculationA power calculation is a way to figure out how many people or data points you need in a study so you can reliably spot a real effect if it exists. It balances four things: the size of the effect you care about, how much random variation there is, how strict you are about false alarms, and how likely you want to be to detect the effect. In plain terms: it helps you avoid running a study that’s too small to be useful or so big that it wastes time and money..
Every participant was male, so we cannot assume the same results apply to female runners.
The researchers tested only 1 vertical climbing speed, 800 metres per hour. We don't know whether the same alignment occurs during slower recreational climbing or faster elite climbing.
The physiological trials lasted 6 minutes and took place on a treadmill. Real trails add prolonged fatigue, uneven footing, rapidly changing gradients, and technical terrain.
The crossover speeds were estimates from fitted mathematical curves rather than directly observed thresholds at every possible speed.

Funding and conflicts

Who funded the study?

The authors' institution, the University of Lausanne in Switzerland, supported the study and provided the open-access funding. The authors declared no competing interests.

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FAQ

When should trail runners start walking uphill?

This study doesn't provide a universal gradient. The runners switched at about 7.2 to 7.3 degrees while climbing at a specific vertical speed of 800 metres per hour, so that number shouldn't be used as a general threshold.

Is walking uphill more energy-efficient than running?

Sometimes. The energetic advantage depends on the combination of speed and gradient, and on the individual runner. This study found a point where the energetic demands of walking and running became very similar.

Can heart rate tell me when to walk uphill?

Not precisely, based on this study. The heart-rate crossover occurred at a faster speed than the runners' preferred gait transition.

Should trail runners practise power-hiking?

Practising uphill walking is a reasonable interpretation for runners whose races include steep climbs. This study didn't test whether power-hiking practice itself improves race performance.

Does walking steep hills make you slower in an ultra?

Not necessarily, but this study cannot answer that directly. It measured short-term physiology and mechanics rather than ultra-running performance, fatigue, or finishing times.

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