[vencislav.popov]

vencislav.popov on November 5, 2020 at 1:43 am · in reply to: Lactate test – AeT seems too high #46546

Hi Scott, thanks for the response – your explanation about the drop around 155 makes sense – that’s exactly where I spend the majority of my base runs, (except for recovery runs).

[vencislav.popov]

vencislav.popov on November 4, 2020 at 9:20 am · in reply to: Lactate test – AeT seems too high #46522

Interestingly, this manual (in German) from SwissOlympic says that the AeT is the point after which lactate increases by at least 0.3mMol (given that intensity increments aren’t too small). If I use this guideline, then I get an AeT of 156bpm because the lactate increases from 0.9 to 1.4 at the next stage (165bpm), and then continues to rise. This value of 156 is right about what I would expect based on HR drift tests

https://swissolympic.ch/dam/jcr:b15b191a-eb0d-46e8-b9c0-417b887a440d/Leistungsdiagnostik_Manual_160201_DE.pdf

[vencislav.popov]

vencislav.popov on November 4, 2020 at 9:01 am · in reply to: Lactate test – AeT seems too high #46521

PS: I measured HR with a chest strap connected to my watch.

[vencislav.popov]

vencislav.popov on April 29, 2020 at 2:18 pm · in reply to: ME – HR too high? #41041

I increased the weight to 68 lb today. Really felt it in my legs, and HR was lower, but still higher than the book/plan suggests (~167bpm). Next week I’m considering trying with even more weight, though I’m not sure if that’s a good idea because of the potential to overdo it.

[vencislav.popov]

vencislav.popov on March 31, 2019 at 11:28 am · in reply to: Stair Mill vs Stairs for Aerobic Pace Workouts #19300

I think that in addition to the factors you listed, it’s the uniformity of movement on a stairmill/treadmill vs the variance in terrain outdoors. I’ve personally noticed that if I go on a consolidated snow slope where I go straight up on snowshoes with the heel lift on, then it feels pretty similar to the stairs/stairmill, because the motion is extremely similar. Anyhow, the main comparison was about training on stairmill machines vs actual stairs or box steps, and as a friend of my noted recently, all of them are much more similar to one another than to climbing a hill, so in my mind training on all should be pretty equivalent.

I did some additional research over the weekend. While there haven’t been explicit comparisons between stairmaster and stair climbing (that I could find), there has been a ton of research comparing treadmill and overground running (on homogeneous terrain). The case should be analogous, because the differences between the two are similar.

This research has concluded that:

1) For a fixed velocity and angle, there is no difference between the energy consumption between running on a treadmill vs running overground (Bassett et al, 1985; https://bit.ly/2JQYb8U). Thus, even though the treadmill moves away and downwards from you (if you are on an angle), if you maintain the same speed, you exert the same effort and get the same training result.

2) The biomechanics of motion over a treadmill and overground are the same (Van Ingen Schenau, 1980; https://bit.ly/2JQYYqo). This article is particularly good because it goes through the math and the frame of reference issue that is the same in the stairmaster vs stair debate. Basically, the fact that the machine is moving is completely irrelevant, since your relative motion is the same when you adopt a frame of reference fixed on the moving surface. None of the forces applied to the body change in any way between the two situations.

In the absence of research on stairmaster vs stair climbing, we could extend these results by analogy, because the situation is pretty similar (moving forward and upwards on stationary ground, vs the treadmill moving backwards and downward and you staying stationary). I’ve added links to the papers above after I accessed them through my university’s subscription.

Refs:

Bassett, J. D., Giese, M. D., Nagle, F. J., Ward, A., Raab, D. M., & Balke, B. R. U. N. O. (1985). Aerobic requirements of overground versus treadmill running. Medicine and Science in Sports and Exercise, 17(4), 477-481.

van Ingen, S. G. (1980). Some fundamental aspects of the biomechanics of overground versus treadmill locomotion. Medicine and science in sports and exercise, 12(4), 257.

[vencislav.popov]

vencislav.popov on March 29, 2019 at 3:31 pm · in reply to: Stair Mill vs Stairs for Aerobic Pace Workouts #19263

Scott,

I’m really confused by your comment concerning CG. What matters in this case is not your CG relative to the ground, but relative to the moving stairs themselves. Regardless of the fact that the stair is moving down, your relative displacement to the stair is exactly the same as if it would be if the stairs were stationary. As a result your leg muscles perform the same amount of work – they are raising the same amount of mass the same distance (because you are moving down with the stairs as well, so the effect is negated). Imagine three escalators next to each other. E1 is moving down without accelerating, E2 is moving up without accelerating, E3 is stationary. You perform the exact same motion at the exact same rate on each. Since motion is only relative to a specific frame of reference (special theory of relativity), if your frame of reference is the steps themselves, you have moved the same vertical distance on E1, E2 and E3, and as a consequence have performed the same amount of work (which is force multiplied by distance traveled in the opposite vector direction). The fact that the three elevators are moving in different directions (or not at all) is irrelevant with respect to your body and the amount of work it has done. They could even be moving at different speeds, but as long as your relative speed to the steps remains the same, there would be no difference in the amount of work performed or in the relative displacement. Because your relative displacement with respect to the grounds frame of reference is irrelevant – it doesn’t factor in at all in how the physics of motion and work play out. Maybe I’m just missing some nuance to your argument?

Ven