Power to weight?

bike boy

Hi,


Is the power to weight levels that alot of people / books etc talk about maxiumum aerobic power (map) or threshold power ? (i thought the second but not sure now)

Just been reading something about Maximum Sustainable (MS) power and it said that Bjarne Riis had a (ms) of 7 watts /kg during the 1996 tour and big mag had 6.8. so what is Maximum Sustainable (MS) power ? is it the same as MAP?


Thanks in advance

RapDaddyo

Depending on context, it's possible that someone is talking about either a MAP/kg or a threshold/kg. BTW, when you say "threshold," it could be taken as either lactate threshold (LT) or functional threshold (FT).

These are probably references to functional threshold, often inferred to be 40K TT max sustainable power or 1 hr max sustainable power. Personally, I prefer to refer to all max sustainable power numbers at specific durations (time) rather than distance. If your FT is 300w+, then a 40K TT is ~1 hr (assuming a flat course and no wind), but if your FT is 250w, then a 40K TT is considerably longer than 1 hr. Nonetheless, many people are assuming a 40K TT when they say functional threshold.

acoggan

Since the power-duration curve is so flat by the time you get out this far, it really doesn't make any difference whether you say ~1 h or 40 km.

bike boy

I was thinking of lactate threshold (LT) ok this opens up another can of worms! what is functional threshold (FT)?


Is a 40 k TT not ridden at or near threshold anyway?

ric_stern/RST

I'm just in the process of writing a glossary of terms...

anyway, 40k/1-hr TTpower is ~ 10 - 15% greater average power than LT. I'm not 100% certain what FT is, and hope Andy will send me a quick note on it so i can add it to the glossary (FT is a term developed by Andy - as far as i'm aware).

ric

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acoggan

I called it "functional threshold power" because, regardless of what blood lactate levels might happen to be, from a functional perspective there is a threshold power that you can maintain for a significant period of time w/o slowing down/fatiguing. Others have referred to this intensity as "coach's or athlete's threshold", reflecting the fact that most people associate the concept of threshold with this higher intensity, versus the point at which blood lactate levels begin to rise (as evidenced by the poster to whom you replied). You could also call it "maximum steady-state power", as Dave Morris has done. In terms of scientific studies, the closest concepts/definitions would be critical power, maximal lactate steady-state power, and/or individual anaerobic threshold (esp. the first, since it is purely a performance-based measurement, whereas the last two involve measuring blood lactate).

ric_stern/RST

thanks

would there be a duration associated with this measure?

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acoggan

No and yes. No, in that functional threshold power isn't strictly defined as the power you can maintain for a specific duration. Yes, in that functional threshold power can only be maintained for a certain duration (that duration being ~60 +/- X min, where the magnitude of X depends on just how tightly you think you can specify functional threshold power).

To put it another way: I consider my functional threshold power when I'm fit to be 300 W (which is essentially my critical power, although I don't rely on critical power testing to determine my functional threshold power). If you put me on an ergometer and ask me to ride as long as possible at 300 W, I'd probably last between 50 and 70 min, depending on how good of a day I was having. OTOH, if you asked me to go as hard as I could for 50 min and I was having a really good day, I might average as much as 305 W, but no more. Similarly, if you asked me to go as hard as I could for 70 min and I was having an off day, my power might be as low as 295 W. So, if my functional threshold power can be narrowed down to the nearest 5 W (i.e., +/- ~2%), then the duration that I can sustain it is 60 +/- 10 min. However, if you view functional threshold power as being more variable (say, +/- 10 W), then the corresponding time window would be wider.

ric_stern/RST

so, in other words it's virtually identical to what i'd term term ~1-hr TTpower.

ric

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acoggan

Right - but what I was trying to get at is the fact that identical to (virtually or not), and defined as, are not exactly the same thing.

An analogy (which I'm sure you'll appreciate) is the oft-made statement that "my LT is XXX beats/min". As you rightly point out, this is incorrect, since LT is an exercise intensity, not a heart rate. You could, though, say that "my LT is an exercise intensity virtually identical to that which elicits a heart rate of XXX beats/min", and you'd be correct. Correspondingly, I wouldn't say that "functional threshold power is ~1 h TT power", although it is correct to say that "functional threshold power is virtually identical to the power you can sustain during a ~1 h TT".

Ain't semantics fun?

roadcyclist101

That power to weight of Riis sounds huge! 7?
I'm new enough to cycling, but had a V02 max test done. My power to weight was only 4.9 Watts/kg at Lactate threshold. I was told to train for 15 minute intervals at ~10 - 5 beats below lactate to improve that. The load at lactate threshold was 330 watts and V02 max was 82. Anyone with similar numbers have training advice to improve power to weight, or are those intervals the best thing? I don't have a power meter, but could go to a gym with a power thing on the exercise bike for intervals if power training was better than heart rate.

On another point - my haemocrat was ony 42% (sounds low) but my v02 max was 82 (sounds high) - I would have thought that these would be correlated. I guess the V02 max depends more critically on other stuff other than the ability of the blood to carry oxgen. Anyone else think its strange that these aren't correlated or am I missing something?

Spunout

Why can't we all get along?

If we look at the Power Profile chart http://www.cyclingpeakssoftware.com...rofiling_v3.xls, we see power-to-weight numbers for all peak times. So, while we would all like to have one number to speak of, four may be better. We are using so many different measuring sticks (TP, MAP, %MHR, etc) it is impossible to compare.

In the meantime, I'll just say I'm 20 w/kg Mr. 60% has nothing on me.

roadcyclist101

O yeah, I suppose 7 W/kg might not be too huge when you look at 60% haemocrat

bike boy

I think riis value is about right as he did win the tour not a 3rd cat race

If you are 4.9 and fairly new to cycling i would imagine his score to be about right