power output in the alps

Grifteruk

I've been to the alps for the past couple of years but this year ive started training with power and am looking to try to figure out required outputs for some of the climbs ill be doing this year. Im planning hour long turbo efforts to try and mimic as far as possible

typically ive achived times of just over an hour on alp dhuez, at 1hr 3mins and 1hr 8 mins (the slower being on a very hot day). Both times I weighed in at 68kg.

As I am eager to break the hour can anyone point me in the direction of how to calculate the req'd power output to manage it? Im determined to manage it this year !!

Cheers in advance

bigpikle

check Alex Simmons blog as he had a chart specifically looking at power outputs (w/kg) needed for different times up AdH.

IIRC 4w/kg was needed for a 1hr time but double check.

Grifteruk

Thanks for that found it. Managed an hr on turbo earlier at 258watts average so technically not too far away but I get the feeling its not gonna be that easy !!

FatTed

Provided your bike + Gear is 8 Kg

Grifteruk

Yeah was thinking about the bike weight side of things - luckily my summer bike is well under that limit and hopefully ill be a few kg's lighter than 70kg by the time July comes around. Already sitting at 68.5kg whilst still carrying a bit of damage from Christmas !

bahzob

I'd back up, 4w/kg should do for a sub hour time. However in my case at least that's bodyweight only

70kg@285W = 58:30 mins (full 13.7km route, bike was an extra 8kg or so)

For this and other climbs I find this calculator to be pretty good

http://bikecalculator.com/index.html

Grifteruk

Thanks guys:

Calculator looks good but no doubt will keep me awake when I start to get closer to the time!!

I'm a bit surprised with my turbo effort last night as my heart rate stayed low in comparison to normal efforts of that type and duration and I felt like I had more in the tank at the end. Appreciate the difference between watts and HR but was still odd from my previous experience.

I've previously cross checked my power readings on the turbo bike with my powertap on winter bike and they were comparable -/+ 2%, but will stick both on at the same time and test it again to make sure. Fingers crossed its not a false reading.

markwb79

Really good calculator! I like it a lot.

bahzob

Grifteruk wrote:

Thanks guys:

Calculator looks good but no doubt will keep me awake when I start to get closer to the time!!

I'm a bit surprised with my turbo effort last night as my heart rate stayed low in comparison to normal efforts of that type and duration and I felt like I had more in the tank at the end. Appreciate the difference between watts and HR but was still odd from my previous experience.

I've previously cross checked my power readings on the turbo bike with my powertap on winter bike and they were comparable -/+ 2%, but will stick both on at the same time and test it again to make sure. Fingers crossed its not a false reading.

HR can be a useful supplement to power, especially if conditions are controlled as they should be on a turbo. If you are doing repeated sessions of an hour or so steady, relatively high, power like simulating a climb of Huez then one good measure of improvement will be lower HR for same power. It's certainly something I notice.

If your bike computer/analysis software allows another useful measure to track for sessions like this is cardiac drift aka "decoupling". Basically this is just a measure of how closely HR matches power over a ride for steady state endurance efforts.

WKO provides this automatically and it's explained here http://home.trainingpeaks.com/blog/article/aerobic-endurance-and-decoupling

It doesn't need WKO though, just the capability to record average HR plus speed/distance or power averages.

This is useful because as you get fitter not only will you be able to do more power for the same HR but the HR will also match power more closely through the ride. If the drift as calculated is less than 5% then its a pretty good sign that you can step up the power and still keep it steady through the full session. Alternatively if the drift is high then it may be a sign you are at the limit. It may also, though, be a sign that you are not hydrated or overheating in which case sorting these out should improve things.

As a practical example below is a session I did yesterday, pretty similar I would guess to what you are doing atm.

First half(after HR stabilises): 257W@148bpm
Second half 265W@152bpm
Drift (pw:HR in the summary section) -0.37%
(BTW if training for climbs like ADH I'd suggest doing negative splits like this, it's the best way to pace them for real as opposed to going hard at the bottom and cracking before the top)

This is a great result and shows I am extremely comfortable at this power/HR. Part of my training over coming weeks will just be to replicate this pushing power up each time until I start to see significant drift kicking in, then train at that level with one goal being to reduce it.

Grifteruk

Thanks Bahzob some really useful information there. The point on a negative split is a good one because last year I suffered on Alp Dhuez. Looking back I realised this was because I went far too hard on the bottom. In contrast a variety of other climbs I did in the same week where I paced myself at the outset showed me the mistake I had made. clearly lots of factors but on balance this was the major issue for me.

By the look of it we have a wet weekend coming up so think I will take the opportunity if I cannot get outside to test myself again and apply some of the logic from your post. My longer term plan over the coming weeks appears similar to yours. Repeating these sorts of efforts to try and establish not only what wattage I am comfortable with / can improve upon but also the point(s) at which I take myself over the edge at any given stage of my fitness progression. Having had a power meter for a couple of months I am starting to get the hang of interpreting the information it is supplying.

bahzob

Your power meter should help a lot with pacing, especially on climbs like the Alpe where the hardest section is at the bottom. It can actually be hard to keep under power target then, combination of adrenaline surge + steep gradient makes it easy to go over hard.

One other thing I have to remind myself to do is make sure the cadence I am training at is the same as I will be climbing at. This usually means slowing down rpm on the turbo and/or fitting more gears to increase cadence on climb. If the two don't match than it may expose a weak under trained link that will cause problems.

Good luck, given your training so far + having the use of a power meter I'd be pretty confident that you will get under the hour.

Mccaria

Ahead of going somewhere hilly this summer, I am doing some 20 minute efforts. Yesterday was 20 minutes at 282 watts and 90 rpm and today pretty much like bahzob, I did a 20 effort giving 302 watts at 70 rpm - average heart rate the same on both.

Well worth doing some efforts at the kind of cadence that you will be climbing for the Alpe, it is quite a different feel to the cadence on a usual 1 hour effort. Wish I could climb at 90 rpm, but it isn't going to happen !