Continuing the thoughts about weight – as Chad has said many times on the podcast, you are probably putting yourself in a bad position if you carve yourself down to your lowest possible weight in pursuit of a w/kg goal. You can actually end up a worse cyclist, and a less healthy athlete, by doing so.
My personal experience with this was in the 80s and early 90s, and then in 2015. When I was in my 20s, I kept myself at 67-70 kilos, just because of the mantra “skinny is fast” (I’m 1m 84). From some lab tests, my relative VO2 was 75 ml/kg/min at 68 kilos. But, I was injured or sick at least twice a year, and never made good progress. From those same lab tests, I wasn’t getting as much wattage as I could have out of that oxygen I was consuming – my best 4mmol output was 350w, so a little over 5 w/kg, but my lactate threshold was only 80% of my VO2 max, because the consistency was never there from 87-98 in my training. Always some injury undoing a month or two each year, always colds and flu each year. And I didn’t get much better – it’s hard to make progress when you only train 7-8 months out the year, and spend 4-5 months sitting around healing up.
I took a couple of years away from the bike in 99-00, and then started riding again at 76kg, and I’ve been 75-77 since. Getting proper orthotics and shoes (orthotics for me only solved most, but not all of my foot issues) has been a part of the picture over the last 18 years, but maintaining a healthy weight and being able to train 600+ hours a year has been the big difference.
I’m actually getting more power at MLSS and fat VO2 peak than I was at 68kg – my system is older and not as strong, but there is more muscle mass to use the oxygen, and more power. It’s very possible to keep yourself at a weight that gives you a great w/kg number, but that actually has your body in a weakened state – also, when you get really skinny it’s the fast-twitch fibers that get catabolized first. I’d bet my EVO that I was getting more power for 5min at 45, 77kg than I was at 25, 68kg, just because I had the fast-twitch fibers to call on during aerobic capacity efforts.
Right now I can consume about 5L/min of oxygen, at 52, 77kg. At 25 I was doing 5.1 L at 68 kg. For me (n=1 again), the heavier, more muscular version FTW. A little slower up the hills, but healthier, and able to train consistently without breaking down. I can consume close to what I did almost 30 years ago because of the consistent training volume. My FTP is a higher percentage of VO2 than when I was young and skinny, for the same reason.
Really, w/kg may not be the best goal to target. It’s not “what is the lightest me” but “what is the strongest me” – those are often two very different things. Absolute power will get it done more often than power/weight, unless you’re doing summit finishes all the time…