Home General Training Discussions

power to weight ratio

 okay, I am a bit lazy. I am sure that a full discussion about power to weight ratio exists on the wiki, but folks, I am single parenting it this week and don't have time on my side. Here's what I want to bottom out - I have an FTP of 180-185. I want to get into the 200W club this year in the OS. But I also want to go faster and it makes sense that losing weight will make that happen too. I currently weigh 143 lbs. I think I can get down to 135 without making my entire family miserable, but like many women, I lose the same 5 lbs over and over again. I am v interested in the nutrition plan that Coach Patrick talked about in his IM texas (I think!) podcast, so need to get those resources, but would also like to have some help with the math re for each pound lost = time gained or speed gained. thanks everyone!

 

Comments

  • I don't have any answers, but in reading this I was wondering what the question was. I think you are looking for some sort of correlation - like each pound of body weight lost equates to 5W on the bike, or 10 sec/mile on the run? But I'm not sure.

    (notice those figures are completely made up)
  • There's no easy answer to how much speed you might gain on the bike from improving your W/kg, other than that it'll generally improve. W/kg becomes more important as terrain gets steeper. When you're riding on flats, the effects of aerodynamics tend to dominate. 

    It can be insightful to determine how much time you actually gain from improving your power to weight ratio on specific climbs though. For example, you can weigh yourself before a ride, go out and TT up a climb, and note your power and weight in a spreadsheet. After you get enough data points, you can plot your speed vs. W/kg and see that there should be a pretty good correlation between the two.

  •  Yes, that is what I am looking for. When I was training for martins alone, I had a coach who said that for me each extra pound was worth x,per mile. Was highly motivating. Of cours wit might have been BS!

  •  Anson, here's the thing. I flew up richter pass. I mean I was nt even trying hard and I passed at least 100 ppl who were dying. So I feel pretty strong on hills, but I seem to be plateaued at 26kph. Of course, two years go I was plateaued at 19 kph...

  • Jane — I am pretty sure I read something Coach P had written about the average impact of lbs lost vs minutes saved in an IM — from memory it was 160ish seconds per pound of fat.
  • On the run, 2 sec per mile pace per pound. So, lose 5 pounds, go 10 seconds faster per mile.

    Also see benefit on the bike, but not as easily quantified.

    Bottom line, more watts and less weight are always a good thing
  • Jane, I decided to take on the extra couple pounds this year. I'm a tall girl,5'10" and last year raced at 153 lbs. I'm down to 148 now, with a minimum of fuss. I used LoseIt app on my iPad, which really helped. I've not been successful before at getting below 150, so I'm sure that helped me to be more accurate with counting calories.

    As far as speed, I'm running 20 seconds per mile faster than this time last year. I am faster on the bike than last year as well, but as Mike said that's harder to quantify. My power-weight ratio is definitely better on paper, and I've PR'd my local routes at all distances this year.

    Pick a time of year when you can set your mind to it, and have a high likihood of success. I took my time with this, only aimed for half a pound per week. I would say it's definitely worth the effort.
  • Losing weight is a stressor. Focus on weight loss during a low stress time: the offseason, and maybe the first 3-4 weeks of the OS. Much better success.
  • Power to weight is a relative metric. Like MaxVO2 which is more often expressed in ml/kg/min (instead of absolute ml/min), by prorating output power by mass we can then compare values between people. 200W for a big dude is nothing while 200W for a 45kg person is plenty.

    I am not sure how much value there is in tracking your own W/kg. I would just focus on the output power side of the equation. If you are training well, make taking strides towards your 200W target not only should the weight look after itself but so will your ratio.

  • My 2 cents is that it is much easier to quantify on the run and have roughly heard similar to what Mike said at around 2 seconds per mile per pound with the same effort.

    On the bike, W/Kg is very important on a hilly course. On a flat course, absolute Watts seem to be more important. So on a flat course, the big Dude with a high FTP will generally be faster, but on a hilly course, the little Chica with a high W/Kg will have the advantage.

    Either way, if you want to go faster work on raising your FTP, AND work on losing the extra pounds. It's very hard to do both at the same time. You must fuel your workouts properly, but the extra little things like alcohol and sweets were the obvious things I needed to address. If you get into the 200W club AND you make it down to 135lbs (like you say should be doable) your W/Kg would be up to around 3.26 vs the 2.85 it currently is. That would be pretty darn fast on a flat or a hilly course.

    Even if you don't move your FTP at all but get down to 135lbs, then you'd be at 3.0W/Kg which could be a nice benchmark, or first target to go after...
Sign In or Register to comment.