Well damn. Work on a Sunday. 
250 lbs is 113.4 KG.
assuming a 225 watt FTP, thats 1.98w/kg
+5 watts is 230 FTP. 2.03w/kg
-1kg is 112.4 kg or 2.00 w/kg
So I guess you’re right. It’s because we’re talking about such small increments. I think in my head I was thinking of it more like 5lbs vs, 5 watts. I stand corrected!
And you did it faster than me too!
I personally think in the real world you’re right, simply because it is easier to keep that weight loss going than adding 5 watts a week.
And thats beer math, and I like beer math. 
% relative for each is what’s really important.
There is no simple answer. Take me as an example: in 2019, I was at my lowest weight when I competed for a hill climb TT. I weighed 71.0–71.5 kg and had an FTP of about 311 W if memory serves, i. e. about 4.4 W/kg. During Covid I decided to focus less on my weight and see what happens. My weight went up to 74–75 kg, but my power went up even more. Last season my peak was at 342 W (about 4.7 W/kg) and this morning I tested at 339 W (4.5 W/kg) after completing Base 1.
So which is better? If speed is your priority, it is clear I am faster now. Due to Covid I haven’t competed in the same hill climb again, but it is pretty clear that I’d be faster now. I have some Strava segments as proof.
IMHO if you are within a healthy body fat percentage range, I’d focus on maximizing performance rather than chasing a weight. Of course, I am tempted to lose 2 kg, but that isn’t my priority at the moment. Probably I will have to wait until later in the season or perhaps the offseason to make that adjustment.
Sweep weight at 1kg increments.
Sweep power at 5w increments.
Calculate wkg for all combos.
Then compare [nominal w, nominal kg] vs [-5w, -1kg] for each.
There is a clear cut off where the statement does not hold true.
It makes bigger differences at higher powers.
In the context of FTP, 5wkg riders start to benefit from every kilo lost.
In the context of sprinting, it is no contest.
What is not captured is that lighter riders conserve more momentum going into hills and rollers at speed. So every kg helps when racing rolling terrain. Of course, it depends on your speed… but entering at +5w won’t be as beneficial as losing 1kg.
tldr “it depends”
If you are using lean to mean light, I’d agree that striving to be as light as possible reaches a point where you’ll be getting slower and less healthy.
You can be muscular and very lean (as in low body fat).
Getting leaner shouldn’t have any negative affect on power unless you are dropping to crazy low body fat levels. Adding lean muscle is good if it’s the right type and in the right places. Adding fat does nothing but slow you down and makes cooling less efficient. Not many of us are walking around anywhere close to our ideal body composition for performance. PIc below is Jan Frodeno, a triathlete. He’s about 6’4" (193cm) and raced at around 165lbs (75Kg). Could he be faster if he added more lean muscle? Maybe, but he’s reasonably muscular and he did OK as a pro.
I’ll take the extra 5 watts and the 1kg weight drop as well please. I think most of us have room on both parts of the equation.
This just came up in my mtb race today with 7k ft of climbing. Same race in 2021 I weighed 75 Kilos, today closer to 78 kilos. Rode with about 15 watts more NP for the race this year. Went with full suspension over HT that probably added 1.5 kilos. Thought the gains in descending would offset weight.
Maybe obvious to most but my time got slower by 5 minutes over 4:42 vs 4:37. Overall went faster on downhills but significantly slower on uphills even with more power.
I guess I’ll take both power and weight loss👍
You can use the Watts on the flats as well as the climbs. With that being said, it really depends on your current power and weight situation.
Lol.
But compare his body to Kristian blummenfeld. The dude is 20cm smaller and just as heavy.
Good math’s, but I just feel the need to say that it doesn’t take into account your ability to produce 5wkg, cycling is a strange sport in that we endorse excessive weight loss because it makes you a better climber and confuse under and healthy eating, using your math (and like I say, good math, and I hope this isn’t coming across as a attach on it or you) could be seen as a endorsement for me to lose weight until I get to 5wkg. which I think would be about 10kg, which would take me to around 60kg, or a 5" 10 male, I believe that this would affect my ability to produce my current ftp
Again, math is great, just adding some possible context (really to the entire thread)
Doesn’t this assume no increase in FTP if you’ve lost 1kg. What the basis for that assumption?
Keeping it simple, unless your are a 5w/kg rider, gaining 5 watts would be better. Unless you are overweight and weight loss has the intention of making your healthier overall. Also, it is much more straightforward to create a strategy for continued weight loss than for continued watt increases. Both have a limit, but if you have 10kilos to lose, I’d create a strategy for that easier than for gaining 50 watts.
Yep, lots of different shapes and sizes work, I was just trying to point out that being lean and muscular are not at odds with each other and it’s the best combo for performance and health. In my experience, I put out the most raw watts and feel my best when I’m at my leanest (which is also my lightest).
I’m a 50+ guy with some squish in the mid section and I know I could get leaner and it would make me faster. As a masters athlete, I used to be concerned that I’d lose muscle if I’m dropping weight while training hard and I hear similar concerns from others. A few years ago, I did some dexa scans while I was shedding weight and there was actually some muscle gain along with loss of fat as I was going through my build cycles. It was $ well spent and I learned that even when I thought I was lean and fit, I’m still ~15+% body fat and have plenty of fat I could lose before muscle mass or power would be negatively affected (assuming my nutrition is reasonable). I think most amateurs are in the same boat with watts to be gained and fat to be lost. The risk of losing lean muscle mass while dropping weight is over-stated in my opinion. While it’s certainly possible with bad fueling/nutrition choices, I just don’t think it’s likely for most of us. I highly recommend doing some dexa scans if you have a reasonable way to get them in your area. It was really eye opening for me. N=1 and all that…
Health first, then power.
The basis for the assumption is the original post where the theoretical question was posed asking if its true that 5w gain is better that 1kg weight loss.
Again, if you read the majority of my responses I have acknowledged and supported the idea that both is optimal.
However, the original question, as posed, shows 5w to be a theoretically better gain, up to 5w/kg, as I orginally posted and was followed up by math and graphs.
No brother, I don’t see it as an attack.
I am having a bit of an issue following your points though. My point was up until 5w/kg, the 5 watts is better than losing weight.
The majority of us here are definitely not 5w/kg, so for the most part, the statement of 5w being better than 1kg weight loss rings true, as of the original question posed.
Regarding trying to get as lean as possible, nobody can be held responsible for what other people choose to do, weight loss wise. Its is simply fact, not conjecture, that a properly conducted diet that removes body fat with little loss in lean mass, as long as power stays the same, is better for cycling prowess. I imagine every pro tour level cyclist has nutritionists watching every calorie eaten to ensure the absolute best performance with the lightest weight possible.
There are multiple ways dieting can go wrong, we can overtrain, burn out, etc. But the fact of the matter is, with proper dieting and losing body fat, almost all of us would see performance gains.
This isn’t to encourage anyone to starve themselves. As I said, I can’t be held responsible for what other people do, I can only give my opinions. I am pretty sure this is why trainer road doesn’t talk a lot about weight loss, because some people can really go overboard with it (doing it incorrectly) and ruin their performance/health overall.
Not the first person today, to far in the heat yesterday me thinks
Absolutely,
I Evoq made a good video about it. If you need to lose weight it’s more that you need to change your lifestyle and eating habits for good. Not go on a diet.
Yeah, that works if we are just looking to optimize w/kg. But that approach reminds me of looking at things in the world of economics where a bunch of variables are ignored to overly simplify the answer. Unless we are constantly riding up hill, I’d much rather be a 90Kg cyclist with a 4w/kg FTP than a 50kg cyclist with a 4.5w/kg ftp.
I like to play with some of the pacing apps and mess around with watts and weight and see how they affect expected finish time. It’s been a few years since I’ve looked at it for leadville, but I remember being surprised that a watt and a pound had very similar affects on projected finish times (at least in the weight and wattage range I was looking at). I think a pound was worth a little more, but it was pretty close. I think a watt was worth ~60 seconds and a pound was worth ~70 seconds. There are a lot of variables at that race with drafting, timing of power, etc. that probably were not baked into the model, but it’s still interesting.
