Power meters

[toontra]

Intervals.icu is a decent free site which elevates all your power and HR data to new levels of geekdom. I particularly like the feature where you can compare your peak power records to those of the other users by age, sex etc.

Indeed - and it's free (donations). If you link it to your Strava account then everything is automatically synced. Useful for tracking current fitness and training fatigue over time and compared to past years (personally rather depressing for me ATM )

I actually find all this power info rather motivating, pushing me to improve fitness. I can understand why others may not feel the need though

[ed.lazda]

Figures like weighted power and normalized power, compared to average power, are said to more accurately reflect the physiological cost of your ride. IIRC, it's obtained by taking the fourth root of the average of the fourth power of the individual 1-sec power readings. If your ride varies a great deal in power, the difference is large. If you ride at a constant power, the normalized power is the same as the average power.

[Jdsk]

Does anyone have any thoughts on power versus weighted power? There is often quite a large gap between the two for me on Strava.
...

Is this a value reported by Strava? And do we know anything about the definition and calculation?

According to Strava:

Weighted Average Power
When you ride with a power meter, you'll notice how your power jumps all over the place based on the terrain, grade, wind, and other factors. Weighted Average Power looks at all of this variation and provides an average power for your ride that is a better indicator of your effort than simply taking your average power. It is our best guess at your average power if you rode at the exact same wattage the entire ride.

Looking back at recent rides, Strava has calculated my average weighted power 2-5 watts higher than the actual average power.

Figures like weighted power and normalized power, compared to average power, are said to more accurately reflect the physiological cost of your ride. IIRC, it's obtained by taking the fourth root of the average of the fourth power of the individual 1-sec power readings. If your ride varies a great deal in power, the difference is large. If you ride at a constant power, the normalized power is the same as the average power.

Thanks, both.

Jonathan

[Jon in Sweden]

Thanks for the clarification chaps.

I think that the gap between my stated and weighted power outputs is due to the fact that my preferred riding style is intervals. I really like to climb, and tend to amble a bit between segments and push hard on hills. So typically 220-250w standard and then 400-500w on hills. I struggle a bit with consistent high output, but that variability might be the reason my weighted average is often 10-15% higher.

Every day a school day!

[Jon in Sweden]

Today's 120km ride had a recorded power of 249w and weighted power of 279w. The first half of the ride was at a lower overall power but with many many more hills. The second half had a higher power but not many hills.

[borisface]

You should probably do a test of either 20 min or 8 min flat out to give you your FTP. Then that will help you to make sense of the power you're supplying, it's electrifying. From that you can work out your training zones. 250w for me is close to my threshold and I couldn't sustain it for much more than an hour. But then I'm nearly 100 and only weigh 75kgs.

[Jon in Sweden]

You should probably do a test of either 20 min or 8 min flat out to give you your FTP. Then that will help you to make sense of the power you're supplying, it's electrifying. From that you can work out your training zones. 250w for me is close to my threshold and I couldn't sustain it for much more than an hour. But then I'm nearly 100 and only weigh 75kgs.

I did a 1hr 7m effort last month at about 95% of what I think my max is and it was 332w (351w weighted). So by that logic, I think my FTP then (I'm perhaps a smidge fitter as my training has been very consistent) was around 350w (370w weighted?), maybe a touch more.

My ultimate goal (before I start to decline with age - I'm 40 this year) is to get to 400w FTP. I'm only 21 months and 22,000km back into cycling after 15 years off. I still have some newbie gains to milk, but Father Time is breathing down my neck. I'm very lean, but have a couple or three kilos of fat that could be lost but that's more relevant to VO2 max (something I'd like to have tested this summer too).

I love statistics. It's really a fascinating aspect of cycling for me.

[borisface]

350ish watts would appear to be a reasonable estimate of FTP. That's pretty good going. 400 watts could be achievable if you continue to progress and certainly is a good goal to aim for, sometimes losing weight can have a detrimental effect on FTP. I'm currently trying to get up to 4w/kg at FTP and whilst my peak powers are good for shorter durations, the 8 minute seems to be making much slower progress.

Do you race? Maybe you should.

[Jon in Sweden]

350ish watts would appear to be a reasonable estimate of FTP. That's pretty good going. 400 watts could be achievable if you continue to progress and certainly is a good goal to aim for, sometimes losing weight can have a detrimental effect on FTP. I'm currently trying to get up to 4w/kg at FTP and whilst my peak powers are good for shorter durations, the 8 minute seems to be making much slower progress.

Do you race? Maybe you should.

Thank you.

I'm only 21 months and 22,000km back into the saddle, so still a way off peak fitness I think.

I don't race, no. I am not much of a fan of it and found it stressful when I was a kid. I do hope to organise a gravel race here next year though. I'd like to do it as a Gran Fondo style event though, with timed sections (all climbs). That way, you can still cycle most of it at a pleasant pace, enjoy the food on the way round, but put pedal to the metal when it's required.

4w/kg would be very good. That's about as high as I can ever hope for given my size. If cycling were my sole focus, I could lose 15kg, but it would all be muscle and mostly from my upper body. Life is more than just how fast you can climb a hill, and being physically strong is important too. Especially for longevity.

[borisface]

I used to race (road, track and TT) as a kid and got my first cat licence in the UK. I then damaged my knee and had 17 years off, resuming when I was 40. I did some TTs in the UK but never got up to where I thought I should be, partly as my weight didn't budge lower than 82kgs. I have done quite a few granfondos over here but I had a bad crash at 66 kph when I hit a cat that was scared by the riders and ran across the road in front of me. So I've been persuaded against doing those in the future. I'm interested in doing some zwift racing but my internet connection in rural Portugal ain't great so I have to content myself for now for racing against the numbers and trying to better the local lads. Pushing 57 I'm in a bit of a race against time!

[Jon in Sweden]

I used to race (road, track and TT) as a kid and got my first cat licence in the UK. I then damaged my knee and had 17 years off, resuming when I was 40. I did some TTs in the UK but never got up to where I thought I should be, partly as my weight didn't budge lower than 82kgs. I have done quite a few granfondos over here but I had a bad crash at 66 kph when I hit a cat that was scared by the riders and ran across the road in front of me. So I've been persuaded against doing those in the future. I'm interested in doing some zwift racing but my internet connection in rural Portugal ain't great so I have to content myself for now for racing against the numbers and trying to better the local lads. Pushing 57 I'm in a bit of a race against time!

Sounds like you had a very similar experience to me. I did a lot of 10 mile TTs, competed once nationally (against Mark Cavendish no less! ) but then got chronic tendonitis in my left knee and stopped age 16. Back on the bike at 37 and I'm 39 now.

If ever you want to experience Swedish gravel, give me a shout. I'm a roadie at heart but ride gravel in practice because it's just so very, very good here. I tend to ride more road in winter during periods of thaw and I need a speed fix after weeks (or more) on studded tyres. Gravel can be tough in winter with persistent ice.

Either way, it's lovely that you rediscovered your love of cycling again later in life too. Hurrah for middle aged men in lycra!

[borisface]

Cycling is one of those things where some years/months you have tons of enthusiasm and motivation and others not so much. For me that's often weather-dependent, so you do really well to motivate yourself in the Swedish winter. The fact remains cycling will always be there.

[Jon in Sweden]

Cycling is one of those things where some years/months you have tons of enthusiasm and motivation and others not so much. For me that's often weather-dependent, so you do really well to motivate yourself in the Swedish winter. The fact remains cycling will always be there.

Thank you. I find getting out is very good for my mental health. If I manage it (which is going to be tight, due to the shorter month and volume of snow), this month will be my 12th straight month of 1000km plus.

Interesting observation today whilst out on the Mercian tourer (work bike/wet weather bike). Half way into a 37km recovery ride, I had one half of one chain link snap. I then had to ride very gingerly home with the smoothest pedalling you've ever seen.

I think that usually I am a bit stampy with my pedalling style. Most of the power comes on the downstroke. Today, I made a concerted effort to smooth out the power delivery around the whole rotation, pushing forwards from 12 until 3 (when viewed from the crankside), down from 3 until about 7, and then pulling up back to 12.

I understand that this is a common pedalling technique for MTB riders where traction is seriously limited. The upshot for me was a much great power output for the same heart rate. So whereas 120bpm would usually equate to 200w for me, I was getting 230-250w for the same stable heart rate.

I'm on a longer, faster ride tomorrow, so I'll test this hypothesis on the road and see how it pans out. My theory is that by having a smoother, fuller pedal stroke, you engage more of your leg muscles, reducing the strain on your CV system. Whether this would sustain for an entire ride is another matter and one I intend to investigate.

[foxyrider]

I don't have a power meter so i've no idea of my ouput but that pedaling action is surely what everyone does? Well its how i was taught anyway.

As for getting home with the broken side plate - its happened to me a couple of times, the last time i got it back home 50km from where i discovered the issue.

I've tried doing 'recovery' rides - when i check the stats afterwards i've usually ridden exactly the same as the rest of the time, just less far!

[Jon in Sweden]

I don't have a power meter so i've no idea of my ouput but that pedaling action is surely what everyone does? Well its how i was taught anyway.

As for getting home with the broken side plate - its happened to me a couple of times, the last time i got it back home 50km from where i discovered the issue.

I've tried doing 'recovery' rides - when i check the stats afterwards i've usually ridden exactly the same as the rest of the time, just less far!

The broken side plate was a new one for me. All the more amusing that it went when I was intentionally limiting my power output.

It's been a good week or structured rides. Two days of solid zone 2 training (37km each time, 137bpm each time - no power data as ice present so on a bike without a power meter) and then 37km recovery at 120bpm. 120km tomorrow, at I'd guess 140-145bpm average.

Either way, I feel like the power meter has improved my training thus far. Over summer, I should be able to do nearly all my rides with them as I'm selling one of my incompatible bikes and my other one is a winter bike.