Do you struggle to achieve the same power output when riding on flat roads compared to uphill?
A recent study published in the Journal of Science and Medicine in Sport suggests this difference is very much real.
Is uphill power different to flat power?
To investigate this question, Valenzuela and colleagues examined power data from 98 male cyclists from World Tour and Pro Team level (1).
Over a 10 year period they collected and reviewed 1074 files from each cyclist. Data was collected during both training and racing.
Power data was analysed for power records (mean maximal power) across durations of 1, 5, 10 and 20 minutes. To ensure that they examined maximal efforts, they only included participants whose power records were above the 10th percentile of normative data for professional male cyclists.
What did they find?
The authors found a clear difference with significantly higher power records being achieved during uphill than level cycling.
5 and 10 minute absolute power was 0,4-3,6% higher during uphill compared to level cycling. Higher power records were found during uphill cycling for all durations examined (1-20 min).
The highest power records were achieved on slopes of 5.9-6.9%, regardless of effort duration.
Could race tactics influence the result?
You need to take into account that these results were based on retrospective analysis of training and race data. As such, we should ask if differences in power outputs in flat and hilly parts of the course were affected by how the races unfolded – such as riders simply making harder efforts in the uphills or other race tactics.
Indeed, the authors thought of this.
To examine this possibility, they subdivided riders by speciality, into either “climbers” or “flat specialists”. And then compared results between the two subgroups.
Interestingly, there was no difference. Both the climbers and the flat specialists achieved their highest power records in uphill terrain.
You could hypothesise that more flat specialists would execute maximal efforts in flat terrain than climbers. Think of scenarios like echelon riding in cross-winds, establishing break-aways, towing the peloton to catch a break-away and positioning the team sprinter in the front before a bunch sprint.
It would probably be fair to say we cannot rule out entirely that race tactics may have influenced results. That being said, the fact that there was no difference in the uphill vs flat power record relationship between climbers and flat specialists strengthens the findings of this study.
To this end, previous studies have also described higher power outputs in certain effort durations when experimentally testing the difference between uphill and level cycling (2-3).
Why are higher power outputs seen in uphills?
This study did not perform other assessments than power outputs. As such it cannot explain why the observed differences came around.
That being said, the authors speculates to the following potential causes.
Inertia: the greater inertia obtained during level cycling may prevent cyclists from achieving higher power outputs during level cycling.
Body position: cyclists may adopt a more upright position, or even standing position, during uphill cycling. Which may facilitate greater power output.
Biomechanics: differences in pedaling patterns and muscle activation have been reported in uphill cycling. This too may potentially contribute towards a difference between uphill and level cycling.
Cadence: differences in cadence might impact the results.
However, it must be emphasised that for now, the reason for the observed differences in power output between uphill and level cycling remain unclear.
Take-aways for your training
The important take-away from this study is that it appears you may achieve higher power outputs during uphill cycling than during level cycling.
The highest power outputs seem to be achieved on gradients between 5.9 and 6.9 percent.
As a consequence, riding at a given absolute power may yield slightly different internal workloads depending on the terrain. This is something to take into account during your training.
- Valenzuela et al. Road gradient and cycling power: An observational study in male professional cyclists. Journal of Science and Medicine in Sport, 2022 (online ahead of print)
- Nimmerichter A et al. Effect of low and high cadence interval training on power output in flat and uphill cycling time-trials. European Journal of Applied Physiology, 2012;112(1):69-78
- Hovorka M et al. Effects of flat and uphill cycling on the power-duration relationship. International Journal of Sports Medicine, 2022;43(8):701-707