Got a power meter - first ride... Observations and questions
CptKernow
Posts: 467
Just got myself a Favero Assioma power meter. First ride yesterday was interesting. Firstly, was quite surprised how accurate Strava's power estimates have been, at least for the overall ride average.
However, what was the biggest surprise was how it felt easier than expected to knock out higher watts as soon as the road turned up, but on the other hand it felt incredibly difficult to keep the watts up on the flat.
On the hills I would regularly be hitting 5w/kg without thinking about it. On the flats maintaining 3w/kg took serious concentration.
I read a bit about what the causes this discrepancy, and apparently I'm not alone. Seems strange though as I never had problems knocking out this kind of power on the turbo.
So, would this be something to target, i.e. sustained flat power?
Also, any other suggestions for training with a power meter outdoors would be appreciated. Thanks
However, what was the biggest surprise was how it felt easier than expected to knock out higher watts as soon as the road turned up, but on the other hand it felt incredibly difficult to keep the watts up on the flat.
On the hills I would regularly be hitting 5w/kg without thinking about it. On the flats maintaining 3w/kg took serious concentration.
I read a bit about what the causes this discrepancy, and apparently I'm not alone. Seems strange though as I never had problems knocking out this kind of power on the turbo.
So, would this be something to target, i.e. sustained flat power?
Also, any other suggestions for training with a power meter outdoors would be appreciated. Thanks
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It's why when we talk about good pacing in time trials often the immediate perceived sensation of intensity is misleading when riding on variable gradient terrain.
That said, other than for purposes of learning to pace effort for optimising speed (e.g. in a TT, or managing yourself in a lone breakaway), there is no specific need to be concerned with evening out the effort a great deal. Races don't work that way in any case, and neither does any group ride on the planet.
That said, some days you may want to even out the effort a bit more, while on other days you may want to attack them more. Depends on what it is you are looking to achieve for that day.
As to suggestions, firstly just ride and collect data. Don't change what you are doing right away - it's helpful to gather data on what you've been doing, Then you can review and begin to make some assessment as to whether or not some changes are in order.
Avoid the temptation to stare at the numbers lest you might crash or injury someone else.
Learn the features of your meter and learn how to use it correctly, learn about calibration and torque zero and whatever else may be required to ensure your data is as good a quality as it can be.
Eventually you might look to do some specific test efforts to get a sense of your capabilities: short duration sprint efforts, hard maximal aerobic efforts of a few minutes, longer hard aerobic efforts of 20+ minutes.
Perhaps get your hands on the book "Training and racing with a Power Meter" by Allen & Coggan. Full of all sorts of useful information, advice and ideas about how to get much more out of your power data.
Ask questions.
Think I'll have a go at a 20 minute max effort over the next week just to see where I am compared to my indoor trainer. Will also see whether there are any surprises in the figures I get from my next few rides.
Though one main thing i will chip in regarding actual averages is that I tend to find over intervals on the flats, the actual average can come out a fair bit lower than you might anticipate.
For example, you could be constantly riding to say 250w on your display, but then when you end your ride and do your analysis, the average comes out at like 235w for that block.
I tend to find that this is the result of "micro-rests", i.e. momentary external factors that can cause you to stop pedalling for a few seconds over the course of an interval, e.g. going around a corner, slowing over a pothole.
It is rather annoying as these can make your averages feel lower than that on the turbo for a pretty much equal effort, given that 1 second here and there doesn't give you any time to recover. Mathematically speaking, it's just down to averages, so for example, 10s of not pedalling across a 10 minute interval will yield 98.3% (590/600) of your "target power", i.e. which will knock your 250w average down to 245w. Which can feel pretty significant for a random second here or there. (You may look down constantly at your head unit and see 250w, then be surprised when you see the average being lower)
It tends to happen far less up hill as you are both moving slower and thus have less ground to cover and less chance of needing to avoid something, or negotiate a turn.
The reason I mention this is because it can be a very valid explanation for why power numbers can be lower outside, or even why there can be a pure power discrepancy between riding up hill and on the flats. Most people don't consider micro "rests" to actually impact the average a lot, but they do. Equally, if you try to compensate the live interval average, you end up having to ride above your target power which can cause you to fatigue if you aren't careful.
As an example, making up for that 10s at 0w would require you to make up 2500J worth of exertion, which can either be riding at 500w for 10s, or riding at 290w for a minute. Crazy huh?! (The gap gets more extreme at higher wattage intervals, given you need to make up for more work done, and can be a reason why it can perceivably take longer to boop your long interval averages up in the real world, and equally why TT's often yield a lower avg power than what you actually target)
I personally just employ the strategy of knowing that on average, these drops are going to happen most of the time anyway, so I tend to just stick to my target power and not go over it, knowing that over time, the averages will increase anyway. Trying to make up for a dropped average can mean training in the wrong zone and ruining the quality of future intervals, or tiring yourself out too early. (By this i mean if I want to target 250w lets say, i'll try to always get my power to that, and I don't display ride average,as this often causes me to surge to bringi it back up. I then just accept that after the ride, the actual average may come out a bit lower.)
I'll add that normalized power does tend to remove these anomalies and is more representative of the physiological cost, however you generally only see NP for the whole ride, rather than an individual interval or segment, and it is said that most NP algorithms do not work accurately for a duration of less than 15 minutes anyway. Another solution is to remove zeroes from the average, however you can then fall into the otherside where you don't consider valid rest enough. While 1-2 seconds may not be enough to get recovery, 5-10s is, and not including those zeroes would also be a disservice.
I too found Strava surprisingly accurate for ride average and most of the hill climbs apart from efforts known on the day to be severely wind impacted.
Probably the biggest eye opener so far was earlier this week when for the first time I tried to do some formal hill reps and I witnessed just how badly my output was fading as I went up. In this case I was hitting the lower slopes on the big chainring and changing half way up so next time I want to try a different approach to see if it improves things.
Easty commuter
Tripster AT
This is perfect for me as I commute on the bike but rarely get a chance to hit the turbo.
It tells you if you need to increase training load (in which case I take the long way home and hit the hills) or if I'm overdoing it I just pootle.
The process of trying to create breakthroughs in your fitness profile is quite addictive, although now that it has me dialled in it's quite spooky how accurate it is - it knows when I'm spent!
I did a slightly un-clinical FTP test on Saturday (I actually ran out of road as I set a PB despite a headwind!). Was really happy as the figures more or less matched my turbo figures - which I always assumed were slightly flattering.
Anyway, genuinely excited about the whole new world of pain that awaits me outdoors...
I presently have trainingpeaks premium - I like the interface and layout.
But are you monitoring 'lap power' as you ride? I've got that on a screen just for reps and hill climbs along with 3s and 10s power and gradient. Just hit the lap button and you're away. Then if desired you can just focus on that figure.
The point i was more making was with reference to intervals on the flat, saying that due to micro-stops, it means you have to ride above to pull your average back up. For example, in the case I gave where you had 10s of tiny rests spread out across a 10 minute interval pulls the average down from 250 to 245w, meaning that if you want to balance it out, you would need to target 290w for the final minute, or overall target ~255w.
On the flat when you have tiny stoppages can require a higher physiological cost to compensate for it to get that average up to your original target power 250w, which is one reason why intervals can sometimes feel harder on the flat, because you are more likely to encounter hazards or turns which require you to stop pedalling for a second. And 10s across 10 minutes would feel like nothing, but it does have a significant impact.
- so to conclude, I mean that if you did target lap (or whole) average power on the flat vs a climb, the one on the flat could be more like riding at 255w,for the same 250w average, given an increased time spent at zero watts (though often no more than one second at any given time, so you don't get rest benefit from it).
Interestingly one or two hills around here must be convex shaped, because I can see the power ease off as I crest the summit. Its good to have the power meter so I can keep the power on.
Every 6 weeks or so I do a 20 minute FTP, to calculate zones. Then just use these to gauge the effort of my cycling. Aiming for an endurance zone on long rides, tempo on normal rides or threshold / VO2 max on hard efforts.
Was a bit surprised by this as I thought the effect of added resistance would be the same as riding up hill. However, I really had to concentrate even to keep it at tempo power...
Haha yep that was one of the first things I discovered too - there can be big difference between going out and riding to achieve a high average speed or a high average power! Plus holding a constant power for a whole ride is pretty much impossible.
I have to admit most of my turbo stuff is done on the hoods and the FTP test I did on the road was nearly all on the hoods.
I suppose I know the solution to this one...
Great choice, I've had a BePro and it's been faultless for 3 years.
I used the PM to keep my efforts below 3.5w/kg on climbs most of the time, and instead of being wrecked the last few miles home I was able to keep that power output even on the last climb to home. I ended up with an average speed higher than I’ve ever done the route before, and it’s a regular route too - despite pretty much ignoring what speed I was doing and just keeping an eye on the power.
I wasn’t sure if a PM would have been a bit of a wasted purchase, but I can see now it definitely won’t be!