Power question

[Windbreaker]

 

Here is one for Bikemax and all of the other coaches who have enough experience with power training.

 

I've posted a conversation thread from cyclingnews below (sorry admin) For some time I battled with this concept and I always did my 20m L4 intervals on Ou Kaapse Weg or Red Hill because I felt that it was easier than on a flat section. This year I started focusing specifically on flat work and although I am not anywhere near the same fitness level as last year (TSS way down) I definitely feel stronger on the flats. I've also got to the point where I am comfortable in the drops for 20m plus.

 

Still have to compare power files to the same time last year to see if it confirms my feeling.

 

So is there actually a different "FTP" for uphill, flats & downhills? I think that there is, but I suppose that there isn't enough to warrant creating different zones.

 

Quote

Power training

Why is it easier (or more doable) for me to constantly push 300-350 watts up

a hill for 30-45 min but then when I try to create that same power output on

a flat to slightly downhill time trial I get nowhere close to being able to

hold that wattage? It is boggling my mind.

...

Thanks

Bart Boma

 

Sacramento, CA

Scott Saifer replies:

Hi Bart,

Your situation is extremely common and most likely correctable: Are your

cadences similar in the uphill and flat-downhill scenarios? If you are spinning

down hill but mashing uphill, you likely have not developed the coordination

to make the high wattages at higher cadence. That can be corrected with practice.

 

Is you position the same in the two scenarios? If not, you TT position may

be too extreme to allow you to make efficient use of the muscle strength and

aerobic power you have. You can test this by trying to climb in your TT position

at your normal climbing cadence. If your power is down when you do that, rethink

your TT position.

Finally for whatever reason some people simply find it easier to push when

something is pushing back. If this is you, you'll need to work on motivation

for the downhill performance; picture being in the winning break at Milan

Sanremo.

Dario Fredrick replies:

Hi Bart,

With all due respect, I disagree with Scott in that your situation (or motivation)

needs correcting. You are simply experiencing basic laws of physics as resistive

forces in cycling, specifically gravity and aerodynamic drag. All of us who

use power meters are familiar in practice with what you describe.

When considering climbing power, gravity is a constant which is multiplied

by the slope of the road incline (~gradient), and it exerts a greater relative

force versus air at a given speed. It is "easier" to produce higher power

if the resistive forces are greater. On flat terrain, you have to work to

develop speeds high enough to exert sufficient resistance in aerodynamic drag

to maintain TT power - whereas on a negative gradient (downhill) resistive

forces are further reduced, making it "harder" to maintain TT power.

Let's assume that your 30 min TT power *average* is ~335 W (+/- 10 W), thus

on flat terrain it is ~335 W, uphill ~345 W and downhill ~325 W.

 

Windbreaker2007-12-23 10:09:19

[VO2max]

WB, for a moment I almost fell from the coach.. I just caught the sentence

"Why is it easier (or more doable) for me to constantly push 300-350 watts up a hill for 30-45 min but then when I try to create that same power output on a flat to slightly downhill time trial I get nowhere close to being able to hold that wattage"..

 

You are putting out some serious wattage...!! then I actually read it properly but man that was a moment of consternation as I am way off those figures and that put you almost in the same category as Bruce...

 

 

 

 

 

 

VO2max2007-12-23 09:50:34

[VO2max]

WB

 

I almost would have asked you to be a tandem partner, then you do all the work and I can sit and relax..

 

 

[Windbreaker]

Ja.... sadly at the moment 20m at 260w (uphill) is about all I can do.

[TXS cyclist]

WB

 

I also found it easier to maintain a higher power output on a hill.

 

This year however I tried to do the 20 minute sessions on an indoor trainer and found that it is actually easier to maintain constant higher power output on the indoor trainer, because even on a hill you have slight increase /decrease in elevation and that disturbed my rhythm.

 

Normally the opposite happens on an indoor trainer because heat play a huge role on an indoor trainer but if you have good fans to keep you cool it might help.  

 

But the fact is; I have a FTP for Indoor trainer and another FTP for Hills. You cannot use one FTP for all scenarios.<?:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" />

[Windbreaker]

I am pathetic on the IDT but I don't believe that it has anything to do with heat. I do my intervals out on the balcony - often in a howling south easter. The trainer is a whole 'nother subject tho

 

But having different FTP values for uphills, flats & IDT's does detract a little from the "science" of power training unless the software developers like Cyclingpeaks agree, recognise and model the difference otherwise you are comparing apples with oranges i.e. a week with hills is not the same as a week with flats w.r.t. TSS etc??

[BikeMax]

Different zones for flat or uphill are not necessary - the second reply is correct IMO, in as far as it is generally easier to put out higher power when faced with a constant resistance in the form of gravity. When you are climbing it is easier to keep the power consistent whereas on a flat or rolling course it requires concentration and focus.

 

Even IDT - with practice, differences become virtually nothing and no adjustments required, although many of us just don't spend enough time or don't cool ourselves sufficiently (just outdoors is not enough - you need air flowing over you to cool you)

 

It comes down to specificity - TT bike , MTB, Hills, Flats, IDT - ride them enough and your power will be good, ride one more than the other and the likelihood is your power will be better in this modality.

 

[BikeMax]

Do a search for "flat Vs uphill power" on the wattage forum and you will unearth hundreds of posts on the topic -  most of the answers seem to stem vary from specificity of training, to motivation, to dealing with the speed on the flat etc - but there is pretty much no physiological explanation for any difference.

[BikeMax]

I liked this summary;

 

"You can picture it like you're trying to push a swing, if you time

your pushes when the swing is stationary or going pretty slow you can

get a good push in. If you try to push it when it's getting away from

you pretty fast it's hard to push with a lot of force -- like if you

time your pushes late.

 

When riding on the flat, or downhill, this effect is manifested as

little drops in power which result in a lower average power.

 

This is the so-called inertia effect, and it's independent of cadence

or the nature of resistance.

 

This might be why some people feel they can ride faster on the flat on

a fixed gear, it provides immediate feedback when you let up, so it

reminds you to stay on the gas."

 

[Racer X]

I personally find hill intervals easier but the moment I hit a flat section in a rece I struggle, I thus flick between the 2 on a bi-weekly basis. Its simple really, find a steep climb or nice long flat road and ride up/along it until you hit 4 minutes or throw up all over your top tube, well which ever one comes first. I managed to get myself to the point where I started to see double and my nose startedto bleed, only done that twice though, pain un imagined etc.

I am saving up for a PT but am still having second thoughts about parting with my 10 k on a hub, I mean the only real advantage that I can see is that with a PT your HR results aren't influenced by your diet, stress levels etc.  

[BikeMax]

 

I am saving up for a PT but am still having second thoughts about parting with my 10 k on a hub' date=' I mean the only real advantage that I can see is that with a PT your HR results aren't influenced by your diet, stress levels etc.  

[/quote']

 

There are many advantages to training with a power meter (and racing), but I am not sure this is one of them. Whether or not you ride with a power meter, your HR will always be affected by the variables you mention - the advantage is that you no longer rely on this very variable metric (HR) to guide your intensity.

 

Some others are;

 

1. Being able to measure and quantify training load - accurately

2. Being able to use the above to plan a build /peak / taper

3. Being able to track progress over various key durations - accurately

4. Knowing when to rest and when to train

5. Being able to review data post ride or race and understand better what happened

6. Pacing - learning the effect this has on success in training and racing

 

A Power meter is one of the best investments of your cycling cash IMO.

 

[Pantani]

 

I am saving up for a PT but am still having second thoughts about parting with my 10 k on a hub' date=' I mean the only real advantage that I can see is that with a PT your HR results aren't influenced by your diet, stress levels etc.  

[/quote']

A Power meter is one of the best investments of your cycling cash IMO.

 

Very true, the past few days I have been riding with my Powertap, just collecting data and am astounded by the new insight I have. Took it with me to KZN and went on some really hilly routes and it has shown me just what a weak cyclist I really am. So, before we even get to using it as a training tool I can already see my weaknesses just by analysing my easy rides.

 

Very impressive device IMO.

 

[butafly]

want to improve power - just do a 4000 m pursuits on the track (from a standing start)

[bruce]

Yesterday on my ride out to Tsitsikamma Toll Gate, I ended up doing the two scenarios on my ride.  I rode up Keurbooms at threshold, then inherited a wheel sucker on the way back wanting a free ride, so I decided to see how long he could last

 

Here is the quadrant analysis of the two scenarios:

 

 

The blue dots are the climb and the green dots are the flat section.  It is clear that the climb is more a quadrant II effort, while the flat is more of a quadrant IV effort.  This gives an indication that there is a different fibre recruitment pattern happening which could well give rise to different RPE.

 

See http://www.cyclingpeakssoftware.com/power411/quad.asp

 

bruce2007-12-24 03:40:57

[bruce]

I am saving up for a PT but am still having second thoughts about parting with my 10 k on a hub' date=' I mean the only real advantage that I can see is that with a PT your HR results aren't influenced by your diet, stress levels etc.  

[/quote']
A Power meter is one of the best investments of your cycling cash IMO.

Very true, the past few days I have been riding with my Powertap, just collecting data and am astounded by the new insight I have. Took it with me to KZN and went on some really hilly routes and it has shown me just what a weak cyclist I really am. So, before we even get to using it as a training tool I can already see my weaknesses just by analysing my easy rides.

Very impressive device IMO.

 

One of the drawbacks of a power meter is that when you are not riding well it becomse a "you-suck-a-meter"

[VO2max]

Bruce, U supposed to be on leave..!! than mean REST a bit.. VO2max2007-12-24 03:49:41