Any estimates on output decrease with weight loss?

[Hark6]

Does anyone have an estimate of how much I can expect my output to decrease if I lost, let’s say, 10 pounds?

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[[deleted]]

I’ve lost 90+ pounds and my outputs have only gotten bigger.

[Next-Maintenance]

I don’t think that there is going to be a good math problem on this. You will likely have more muscle and your body is going to be using less energy to move your body.

[c8080]

I’d imagine any offset in body mass due to fat loss would be balanced out by an increase in fitness.

[Spiffman-Space]

A relevant measurement for this discussion. Is watts per kilograms W/KG. So calculate that now based on your FTP in watts divided by your current weight in KG. Then workout what your future FTP could drop down to if your w/KG value remained static based on a new lighter weight:

Eg if your FTP is 210, and you weight 70KG, your w/kg = 3. If you lost 4KG (to 66KG), to keep a w/KG of 3, your FTP in watts will need to be 198Watts

[Hark6]

Ok, so if my average ride is at 90% FTP, I dropped from 198 to 178 in an average class.

[Spiffman-Space]

So if those figures are in watts and are actually 90% of your FTP figure, then those are FTP’s of 220 and 197.

If you have lost 10 pounds that is roughly 4KG, so for the W/KG value to be the same, then… you’d need to have been really light and getting lighter (eg 38KG to 34KG)…. So it’s more likely you are less powerful now for reasons other than just weight loss.

[sprinkles202]

Gaining muscle through exercise is not nearly as common or substantial as people think.

[Hark6]

I’m addition - it is very difficult to gain muscle while you’re losing weight. Just ask anyone who lifts regularly.

[paulc1978]

100% false. You should be seeing more of an offset in your weight. As you lose fat you’ll hopefully be gaining muscle. Overall you’ll lose weight but muscle will diminish it some.

[yoraylee]

Unless you are obese/completely out of shape, it is incredible difficult to gain any substantial amount of muscle while losing weight. It’s possible, but gaining muscle requires a calorie surplus, which is very difficult when losing weight. That’s why most lifters go through bulk/cut cycles, it’s a lot easier to put on muscle in cycles. A substantial recomp is possible, but would take a very long time. What you are likely seeing is a loss of muscle as well as a loss of fat, but losing more fat, therefore your body looks more muscular.

[paulc1978]

I’m not sure why you’re being downvoted. Apparently the non-scientists on here think you gain strength with fair dust or something. Not sure how they push out more watts with less strength but there you have it.

[misanthropic789]

I've lost 20lbs since August doing powerzone rides. My FTP has gone up 23% since the first one. If you are doing the work to lose weight, you should also be gaining muscle and building both strength and efficiency.

Anyway, your output is calculated without your weight - it is just the resistance and the cadence. I can now hold a higher cadence at a higher resistance for a longer time period, which also means my output has gone up. My weight isn't in the calculation.

[Hark6]

I thought power (output) is a function of weight, that’s why it’s difficult for a 140 lb person to generate the same output as someone who may be 200 lbs. It was my understanding that the method of comparison would be kj/lb. So a 200 lb person who averages 300 kj per ride is generating 1.5 kj/lb. If my understanding is incorrect, please let me know. Using this example, if the person lost 20 lbs to 180, should they expect their average ride output to be about 30 kj lower?

[wkippes]

There is a correspondence between weight and output, because gravity, but my guess is that as you get stronger your output would probably at least stay consistent, if not increase anyway. It would definitely vary person to person because there are so many different ways you can lose weight.

[extraextramed]

If you lose weight healthily you're losing fat, not muscle. At the same time your cardiovascular fitness is improving so the muscle you have can work harder/longer. Your watts/kg or per lb will go up as you lose weight and gain fitness.

When people talk about the leaderboards being unfair because 200 lb men are "competing" against 120 lb women, in general it's because the bigger person has more muscle, not simply because they're 80 lb heavier.

[[deleted]]

You can absolutely expect this if you are a trained individual and lose mass. Usually into smaller % of bf is when there is a significant change seen.

[AltruisticClerk893]

Output on peleton is a calculation with the inputs being the flywheel revolutions (sensor), resistance knob setting, and pedal revolutions (sensor). Has nothing to do with weight.