Comparing different shoes with help of lactate device?

Not the lactate I presumed when reading the title

It's still not a big enough data pool.

What happens if: you're a bit sluggish on one of the days; you got a little less sleep; ate a little less the day before; haven't recovered as well from a previous workout; it's a hot day, etc, etc?

Agree that the data pool might be to small but ideally a result like lets say shoe B is measuring 0,2 lower in lactate than shoe A in general. Then I thought that shoe would be more efficient for my running but dont have tested out yet so result may be all over the place.

Any test stripe has their uncertainty, based on that you need to have >0.2mmol difference (depends on measurement equipment+stripes). You need to run as close as possible below MLSS to see the highest change. Marathon pace is too slow. Should be Half-Marathon pace at least.

You can narrow down a problem by reducing the variables. That means, you reduce to 2 shoes A and B only (skip shoe C for the moment).

Treadmill, to reduce environmental issues. Same day, same time.

Procedure: 15min warm up at a very easy pace (well hydrated, carbo loaded, rested, no discussion here on the warm-up), 10 min shoe A (HM+ pace) -> measurement, 10min very easy to bring lactate down, 10min shoe B (same speed as with shoe A) -> measurement

If you are lucky you see a difference. :) Also store HR and remember your effort feeling for A and B (use a borg effort scale from 1 to 10).

-> show us the result.

Unless you have a research-grade lactate meter, your data won’t be precise enough for you to get anything actionable.

For example, go do the exact same workout twice and lactate measurements can be different by 40-100%, but the trend will be the same.

Might be a fun experiment, but you're probably chasing your tail.

If the difference is significant enough, you'll probably be able to feel that without the measurements. Unless you are training for the lactate threshold olympics, there are lots of other variables that can contribute to a faster race result. I think the most reliable test is to wear them in workouts and other races. I would be more interested in how the shoes felt and performed at the end of a hard workout or long race, as opposed to various 10-minute sessions under ideal conditions.

perhaps i am being silly here but wouldn't the normal process for testing running shoes be comfort/durability and, oh, the time that timing mechanism over there has for the race?

I'd consider using a power meter instead. Run at race pace for each style for a set distance (need not be super long) and see which saves the most watts. This is how cycling does it.

I was just going to reply with: why doesn't running have a good power meter? Maybe I haven't caught up with the times. Is there an accurate meter available? An insole? Cycling has had accurate consumer level power meters for well over 30 years.

Best meter out now is Stryd. Insoles are not going to be around any time soon. Several companies have tried.

S

So did a first test yesterday.

Set up:
* 2 different shoes, Vaporfly 3 (interval 1 and 4) and Alphafly 1 (interval 2 and 3)
* Intervals on treadmill, same as I always using at the gym. Worth mention that this treadmill can not be 100% accurate speed wise.
* 8 minutes run @ 3:20 min/km and 8 minutes rest/recovery (3 minutes to take lactate and change shoes and then 5 minute @ 5:15 min/km).

Test result as follow:
Lactate: 1.3 (VF) - 1.8 (AF) - 1.3 (AF) - 1.4 (VF)
Heart rate avg: 142 - 143 - 143 - 143
Heart rate max: 150 - 149 - 148 - 150

Conclusion:
Not much I guess :) Need to increase speed and see whats happen then. Since day one I prefer the fit of Vaporfly (both 2 and 3) compare to Alphafly but that is just regarding the fit in mainly the toe box.

Interesting.

You second lactate measurement seems to be an oulier (possible sweat contamination).

Based on your lactate and HR measurement, you can not identify a winner.

How long was your warmup? Seems the elevated lactate sample was from not warming up properly.

And i forgot: the pace was too slow to judge. You need higher lactate levels (as i mentioned already) possible around 3-5mmol to see more difference -> higher speed on treadmill (your treadmill display seems to indicate a (much) higher speed as it is in real).

Warm-up?

I would concur with that, especially since HR numbers line up with the other results.

OP, don't sell yourself short on conclusions from the first test. Just because there is no disparity under those conditions, doesn't mean you don't have valuable data. I think it gives you a solid baseline to determine whether or not you have differentiation under other conditions.