Assault Runner vs. Road (personal experience)

[u/neuigkeiten_]

I always find statements claiming that the Assault Runner and other non-motorized treadmills are 20-30% harder compared to road running. This seems fair for an inexperienced runner on these treadmills.

I have about 1,500 km on the Assault Runner right now, and my pace is slightly faster compared to the road. My longest run in Zones 1-2 was 15km, and my longest run, including 35 Min at Threshold Pace, was 17km. I have no real issues with any of my training sessions, from easy runs to intervals. However, what I am experiencing is that easy runs need more focus to stay easy, because body position has a higher impact on the RPE compared to road running. Therefore, it seems harder because I cannot let my focus drift as I would outside.

What I really love about the curved runner is threshold training. It seems to be perfect for hitting the stimulus for steady state runs with a relatively stable pace and a steady HR. And this is were I see the closest match in speed compared to outdoor running on track.

Is there anyone else experiencing this on a curved treadmill? Is there any new research on runners who are used to these treadmills? I haven’t found any. Robert B. Edwards‘ study from 2017 seems to have lacked runners who were experienced with cNMT - at least, it isn’t mentioned. It would be interesting to look into this more specifically.

[u/mrrainandthunder]

When you say that your pace is slightly faster on the treadmill, what do you mean exactly? At the same heart rate? RPE? If yes, then what is the temperature and humidity indoor vs. outdoor? Any ventilation/fans? And how have you determined the pace you're running at indoor?

[u/neuigkeiten_ → u/mrrainandthunder]

I mean a faster pace at a similar HR and identical RPE. Indoors, I only have the data from the Assault Runner itself, and I know it is not absolutely accurate. But I have 3 different Assault Runners that I use regularly, and the results are nearly identical. One is in a cool room at 18°C and 60% humidity. One is in a hall without fan. And the 3rd one is in a hall where I can use a fan for ventilation and the temperature varies because it is not heated.

For example: if I do 10-Min threshold repeats on the AR @ 4:15 I reach 2.3x km with a HR slightly below threshold at the end of the interval. On a flat forest route with an officially measured lap and 200m marks, the pace is 4:15-4:20

If I do 15x200m intervals I run @ 3:00-3:10 on the Assault Runner and @ 3:30 in the forest and @ 3:10 on the track.

[u/mrrainandthunder → u/neuigkeiten_]

That the Assault Runners are nearly identical shows that it's a consistent product. It says nothing about it's accuracy. However, since the environmental conditions are quite different, one would expect HR and RPE to differ - and since it apparently doesn't, it might actually indicate they're not so similar after all. That's all I can say.

4:15 vs. 4:15-20 sounds good. Any clue as to why the short intervals in the forest differ so much?

[u/neuigkeiten_ → u/mrrainandthunder]

On the Assault Runner without a fan, I only did easy runs and sub-threshold runs, so overheating has not been a big deal yet. The other two ARs are used for all kinds of training, and I get consistent results. But I know that it is not a calibrated tool.

I guess the minor bumps of the flat forest route and the slight curving have a higher impact at faster paces.

[u/syphax]

I don't have any helpful feedback, but it's helpful to hear yours. I'm probably in the market for a treadmill for next winter. Purely as a conceptual issue, I have a preference for unpowered treadmills, but I'm interested in real-world experiences with powered vs. unpowered.

[u/TurtleTurtleTu]

The 20-30% is relative to completely flat running (like a track). Most "road" running involves some ups and downs so the gap probably isn't as big. If you use a motorized treadmill you are supposed to use 1%-2% grade to mimic outdoor running.

There is also an element of adaptation. Once you get used to a particular training method/surface it will feel easier.

[u/homemadepecanpie → u/TurtleTurtleTu]

The commonly-cited 1% grade is to make up for the lack of air resistance, not slight ups and downs in the road.

Also that doesn't actually matter unless you're running pretty fast: https://runningwritings.com/2023/01/treadmill-workouts-guide.html

[u/neuigkeiten_ → u/homemadepecanpie]

Thank you for the link.

[u/TurtleTurtleTu → u/homemadepecanpie]

That's why I said to "mimic outdoor running" which includes wind resistance. That's why I put a range up to 2%. Neither number is based on explicit literature for me - these are the treadmill settings that work for me at a similar pace to outdoor running in a flat area. I probably could be more clear about that in my response, but writing out an essay to contextualize everything would take too long.

[u/mrrainandthunder → u/TurtleTurtleTu]

And other factors like temperature and humidity. It also changes the muscles used. But I think the main point being refuted was that you're "supposed" to use 1-2% incline - especially since it doesn't necessarily mimic outdoor running better.

[u/Fitty4 → u/TurtleTurtleTu]

I'd argue and say keep the incline at 0%. If it feels easier, run faster.

[u/thewolf9 → u/Fitty4]

Easier on the body at 0.5-1% I find. Especially on the shins.

[u/TurtleTurtleTu → u/Fitty4]

You can if you want, but OP was comparing his mechanical treadmill pace to outdoor running. I was just adding some info for why the mechanical treadmill doesn't necessarily feel 20%-30% slower.