Power loss to weight loss formula

[Nate@Scarab]

I know, a WIDE-ass range with a lot of variables - but assuming the subject has unlimited fat stores, is there a general range one could look at for FTP decrease vs. overall weight loss?

[DOOFUS]

I don't think there is a formula for body fat%, simply because losing some lean mass helps W/kg (at a short duration power cost).

The key is to identify what the rider is best at -- since you're a pro, ask: what is the thing I have to kick ass at to earn my paycheck?

A sprinter or leadout rider might simply hit a body fat % -- hard to see getting Conti Tour watts for 1min or 10sec and being six one and 70kg, unless the rider is very gifted and has an unusual build for a sprinter.

For a climber (of the 5 min or 20min variety), it's a matter of trial, error, and experience: What is the lowest weight you can hold for recovery and regular training that will allow you to peak at your best w/kg for those predominantly aerobic durations. Weight loss for aerobic w/kg involves losing lean mass -- you *want* to lose some fast twitch muscle to give more fuel to the slow twitch ones that are doing the work. The slow twitch mass will stay. The fast twitch will be catabolized, along with upper body. The question is how much mass can you lose without compromising 1min and under power too much, and without fucking up the immune system from too much lean mass loss.

You have years of power data to look at Nate -- find the mass range where your best performances came at what pays your check. As long as you were healthy and recovering, there is your answer.

[Nate@Scarab]

I don't think there is a formula for body fat%, simply because losing some lean mass helps W/kg (at a short duration power cost).

The key is to identify what the rider is best at -- since you're a pro, ask: what is the thing I have to kick ass at to earn my paycheck?

A sprinter or leadout rider might simply hit a body fat % -- hard to see getting Conti Tour watts for 1min or 10sec and being six one and 70kg, unless the rider is very gifted and has an unusual build for a sprinter.

For a climber (of the 5 min or 20min variety), it's a matter of trial, error, and experience: What is the lowest weight you can hold for recovery and regular training that will allow you to peak at your best w/kg for those predominantly aerobic durations. Weight loss for aerobic w/kg involves losing lean mass -- you *want* to lose some fast twitch muscle to give more fuel to the slow twitch ones that are doing the work. The slow twitch mass will stay. The fast twitch will be catabolized, along with upper body. The question is how much mass can you lose without compromising 1min and under power too much, and without fucking up the immune system from too much lean mass loss.

You have years of power data to look at Nate -- find the mass range where your best performances came at what pays your check. As long as you were healthy and recovering, there is your answer.

Sorry for the late-ass response...I appreciate it.

Unfortunately I don't have years of power data, but I have enough for baseline metrics.

Two-three years back, as you know, I fucked up my endocrine system something fierce from too much weight loss. I was also making shit power. 150lbs with a 350w threshold isn't getting anyone anywhere fast, especially when you can't hang in your aforementioned "fuckme" five minute moments. Shelling everyone with a slow ramp up a long climb was never a problem, but being able to stay with the break at the bottom when everyone hit it was.

Now, I'm relatively huge - 172-178lbs depending on the day. Lack of racing, getting married (read: inheriting three teenage sons), and working the real job tends to put a crimp on things. That said, I've been riding almost exclusively Inigo San Milan-style high Z2 (the happy spot at type I/type II fiber training) for two years, and its given me very solid resilience. My rides are far bigger, from a volume perspective, than anything I could accomplish in my earlier years. I can repeat hard efforts throughout a 5-hour effort or longer without a issue. I recently acquired another PM, and my threshold without interval training seems to be in the 420w range. I'll take 5.2-5.4 w/k without really trying any day of the week, but I'd really like to get back to beating the shit out of fast guys.

If I put my head down for two months, track nutrition, and work on type IIa/IIb training, I'm figuring I could arrive at 150-155lbs or so with fairly minimal power loss at the mid to top-end (but that's just figuring, and the reason for posting). With my added endurance/ability to recover during hard rides and over multi-day efforts, I could be stronger than I ever have. But, the reality is that if I want to get there again, I need to hire a coach and commit.

[Too Tall]

There are a few more involved calculators online however this is going to use the same math and easier to use: Bike Calculator

You can simply plot the numbers you are talking about in a simple spreadsheet and than convert that to display bars or a line. Unfortunately it proves not much since your fitness (sum total of training at that moment) + all the physical factors = power on a given date....so it ain't really relevant to plot your power vs weight over time but it's cool and I get it. I'm no different, when I'm skinny I'm fast(er) ;)

Good?

* Here is a link for some more heavy duty software: http://www.analyticcycling.com

[DOOFUS]

it sounds like we have similar builds and are similar types of riders in terms of morphology and power profile shape -- although you are much, much more talented. I'm six one, and I've been as heavy as 175 and as light as 152. FTP has been around 335-340 for most of my 40s, 5min power around 410. I think I ride best right around 160 -- but it takes me a lot of discipline to get there at 48 (no muffins, no wine, portion control). At 154, I was doing 4.7 w/kg at FTP, but I could only get 450w for a minute -- which meant I got killed in most 40+ races (crits).

My guess is that 160 would be a good compromise point for you -- your life has changed, and with a wife and kids the domestic pro thing might not be lucrative enough (just a guess).


You're young enough that you don't need to fuck around in a gym to maintain some mass. Some 30-30s (sets of 10-20, ~150% FTP on, 50% FTP off) each week will help keep some fast twitch function without dipping too deep into the zone 5 can. There are a bunch of ways to keep a little top end while getting skinny without overcooking.

[boots2000]

You say that you are 172-178.
What do you think your body fat % is now?
If weight loss is mostly fat, I think you can lose little or know power.
If you are doing the kind of morph that requires muscle loss you will lose some power for sure.
Seems like you are doing the kind of training that aids weight loss.
Use the powermeter to guide your calories.
Figure out non riding BMR for the daily activity that you have, add kj for riding, create a 300-500 deficit and weight should drop quickly.
Just need to be consistent with diet and training.
Don't fear carbs- make sure that you get adequate carbs for recovery. Try to eat high quality, non-packaged type carbs. Cooked whole grains and the like.
Not bakery scones and such.

[boots2000]

Re-reading this (and wishing I could edit my spelling errors).
A loss of 178-160 is 10%, not much way to do that without losing a good amount of muscle.
Unless you are a fat bastard (and I am sure that you are not).
My suggestion would be too lose fat in a sensible manner (like I outlined above) and be happy being a lean strong guy.
Lean and strong with high absolute power has many more race weapons than good power to weight but less absolute power.
Might only take you to 165-168 lb.?

[defspace]

Lean and strong with high absolute power has many more race weapons than good power to weight but less absolute power.

I'm nowhere near the OP's level but I'd be interested in hearing more about this. How long do you think climbs have to be for w/kg to be more important than lean and strong?

[DOOFUS]

10-20 minutes, and there would have to be 2 of them at minimum for a masters or P12 race, with a summit finish.

VO2 climbs, there's less of a deficit, and the chance that a chase group could close a 10-15 sec gap from one climb on the flat.

for w/kg to be the deciding factor, threshold climbs (something over 15min long) need to be the deciding features of the course profile.

barring that, absolute power will take it -- especially since most races are decided on 1minute to 5 minute power.

[Badonkadonk]

(no muffins, no wine, portion control).

holy god
no way is racing bikes that fun, is it?!?!

[David Tollefson]

holy god
no way is racing bikes that fun, is it?!?!

It's a disease, not a recreation.

[boots2000]

What Robert said is true.
Rider with high absolute power can hang on most climbs under 10 minutes. Same rider can also make sharper attacks, bridge gaps, create breakaways, and also sprint better than the rider with power to weight as his main weapon.
Riders with both high power to weight and high absolute power tend to go far in the sport.

I'm nowhere near the OP's level but I'd be interested in hearing more about this. How long do you think climbs have to be for w/kg to be more important than lean and strong?

[Too Tall]

Boots and others are right on the money not that it matters for hacks like me.
The above is one reason why I dig track racing, it is short and sweet favoring absolute power.
Climbing the alps is survival and pleasure, don't look for me at the front.

[boots2000]

Are you living in Redlands? Even more reason to just get lean and not go too crazy trying to leverage power to weight.
Races in California are breakaway races, even the ones with climbs.

[DOOFUS]

holy god
no way is racing bikes that fun, is it?!?!

it's called being 48. sugar takes the s out of fast in no time.

I like staying lean

[Badonkadonk]

it's called being 48. sugar takes the s out of fast in no time.

I like staying lean

i'm 38
sugar is death, but god DAMN am i hooked
i wish i could stay lean, but i am too goddamned stressed and too devoid of sleep and too little riding and ah shit, i should probably stop doing this stupid job before it kills me

[Nate@Scarab]

Are you living in Redlands? Even more reason to just get lean and not go too crazy trying to leverage power to weight.
Races in California are breakaway races, even the ones with climbs.

Yes. I think 155-160 is my happy place as well. It's enough of a cushion that if I went overseas for a long stage race, I can get away with taking a long-term beating for a week or two.

I'd say that's true for pretty much every domestic race out there - it's all about being able to hold on for the 30 seconds of eyeballs-popping-out, the 5 minutes of your lungs exploding, and then the slow grind of holding the break. Rarely are you going to encounter a climb longer than 15 minutes in a US race, save at Gila/ToC/ToU - and even Gila is pretty violent, given the length of the climbs.

[cazdrvr]

Sorry for the late-ass response...I appreciate it.

That said, I've been riding almost exclusively Inigo San Milan-style high Z2 (the happy spot at type I/type II fiber training) for two years, and its given me very solid resilience. My rides are far bigger, from a volume perspective, than anything I could accomplish in my earlier years. I can repeat hard efforts throughout a 5-hour effort or longer without a issue. I recently acquired another PM, and my threshold without interval training seems to be in the 420w range. I'll take 5.2-5.4 w/k without really trying any day of the week, but I'd really like to get back to beating the shit out of fast guys.

Can you shed any light on what these high Z2 workouts look like for duration and determining the zone vis a vis HR/Power, Lactate level? Thanks!

[Nate@Scarab]

Can you shed any light on what these high Z2 workouts look like for duration and determining the zone vis a vis HR/Power, Lactate level? Thanks!

Consistent 260-310ish watts (depending on how I feel), HR 145-160ish (again, many feelz), 4-6hr duration. Occasionally I get really freaky and throw in a tempo effort or three (~340W+) for however long I feel, 20-40min. Leading up to the Belgian Waffle Ride (6.5hr effort), I was doing 6-7hrs with long Z3 efforts in the middle and a Z4/Z5 10-15m dickpunch at the end. The key to staying on top of riding like this is maintaining a constant carb/water intake, or you WILL crater.

I don't have a lot of impetus to do hard intervals right now except when I feel like trashing myself since there isn't any racing coming soon. I figure the above for 10-15hrs a week is enough to keep the engine warm and my base there with occasional higher volume weeks thrown in. I never get very tired (from riding alone) since I'm not going long/hard enough. The fitness is enough to go get nasty in a group ride and do ok in local racing with long climbs, but that's it.

Zones are divined from when I was coaching with Dr. San Milan and did his test (the LT test from hell that also pegs cho/fat burn rate), as well as continued self-testing afterwards using the old 20-minute method. Read here for a much better explanation of constant endurance training from the source: What is Lactate and Lactate Threshold | TrainingPeaks

Not saying it's a good training method to win races, but it keeps me fittish.

[ned]

Your problem is that full strength beer in California. If you'd just stick with the Utah grade stuff you'd be skinny again.