If you wanted to just get the best possible time, unless you're already very lean, I'm pretty sure the optimal strategy is something like dieting pretty hard to lose weight whilst doing low intensity volume, not enough to injure yourself given the calorie deficit, but enough to get the short-term plasma volume expansion that comes on pretty quickly with increased volume. But weight loss alone is very effective - speed is essentially inversely proportional to mass at constant fitness.

I'm also returning to more consistent running after years of spotty training. This is a ~linear volume ramp from 15 km per week up to 50 km per week, mostly low intensity, with about 0.5 kg of weight loss per week up to mid-August (and maintaining weight after that). It's mostly Garmin's estimate but the one time trial I ran to test it was ~spot on, I basically believe it.

@chrisjbillington To clarify, 5k obvs benefits from high intensity training, but there's not really enough time to make a dint in any fitness other than plasma volume expansion, which responds to pure volume and takes only a few weeks. Given weight loss, intensity would just be injury risk so not much point. Maybe a little bit to get a feel for what your target pacing for the race should be.

@chrisjbillington thanks for the advice i appreciate it! I like your strategy, ig claude thinks like it can ‘only’ shave 30s bc the weight i can safely lose in 3 weeks (1.5-2kg) is worth 30s of time in a 5km at my pace. Still seems worth doing so adding to my plan. And also volume yeah that is also good advice i did not know about plasma volume expansion or thay it would respond quickly to volume that’s fun.

GL on ur goal!

@traders today i ran 5km in 36min, and claude seeing my pace puts a 3% chance i beat 23min, puts my sustainable pace at 6:30-7:00, puts 85% on sub35, 70% on sub33, 40% on sub30. I think it is too pessimistic but we shall see.

@Bayesian Your 36min felt like you were really trying to complete it quickly? It wasn't just a casual jog pace that felt like it was more of a struggle than it should have been given the pace?

@WilliamKiely

5 laps of ~0.6miles. Isn’t quite optimised for speed, walked much of the third lap, went too quickly the first. I was struggling quite a bit but it felt like a casual jog pace, just pretty difficult

@Bayesian Actually this makes me a bit more hopeful. I'd suggest trying to hold exactly 6:00 per lap (or 3:00 per half) for as many as you can this weekend until you can't keep it up. I think there's a good chance you'll be able to make it 5 full laps or longer even though it'll probably be difficult from lap 2ish.

I feel silly betting against you when you can just run slowly intentionally and have way more information about your current fitness than I do. But betting YES on 29-32 minutes when you ran a 19:20 7 years ago is crazy. Surely you can beat that. I only broke 19 minutes once when I was 16 at my junior year XC state meet, and yet my slowest 5k ever after that (a decade and a half later) after I got fat and put on 45 lbs (or 55 lbs from my HS XC weight) and basically stopped exercising for over a year was still under 23 minutes. If you can't run sub-25 mins I hope it's because you have a chronic health problem you didn't mention or something, because if you really let your body go that much that'd be sad.

Now this sounds insulting, sorry, but I really just hope you run fast and am reporting that I'd be surprised if you can't get 22-25 minutes still.

@WilliamKiely lmao i think you’re probably right. In my head 30min is a respectable time for

Someone that runs the whole way and isnt in great shape so seems like a time i felt i could reach but ig at my age it is pretty easy to make a lot of it back. Tbh i have been really almost entirely sedentary for several years, and recently gained some weight but not quite 45lbs.

Monday i ran and after a few hundred meters my back muscles were overcompensating and hurting from my posture being bad, claude says. Today it was fine. Makes me optimistic!

@Bayesian "In my head 30min is a respectable time for Someone that runs the whole way and isnt in great shape" And who has never been a runner. But for someone who ran 19 minutes a mere 7 years ago? I'd expect the fastest regression to mean to happen around age 18-25, rather than say 40-47, but even then regressing 10+ minutes from 19 minutes in such a 7-year-period seems quite surprising to me.

@WilliamKiely well i basically exercised a handful of times per year during all that time, so i regressed a bunch. And a month isn’t long!

@Bayesian Well I'm definitely updating on how much some exercise helps. I would not have thought that barely any exercise and <45lbs of weight gain would lead to that much regression for almost anyone running sub-20 5ks in 7 years. You should make it a goal to start exercise regularly again and do another 5k 6 months or a year from now and see if you can get back to sub-25 quickly. Even if you run 32 minutes or whatever in October, I would think that you'd be able to shave several minutes off that in less than a year with some training just given your prior feat, though maybe I'm overconfident about that too. Anyways, would be happy to trade on a market about that assuming you commit to exercising :)

@WilliamKiely i think you’re right, i would feel confidentish i can do sub 20 after like 9 months of effort, but yeah consistency is def not my strong suit so that’s a concern. If i think i ll do it ill make a market, sounds fun

@Bayesian I'd bet against sub-20 within 9 months. Unless you're just way more malleable than I am (meaning it's super easy for you to both lose fitness and gain fitness), or the 19:20 you ran was without much training and you actually had the capability to run like a 15 minute 5k at that age if you had just trained a year for it.

@WilliamKiely And by "I'd bet against" I mean "you're crazy if you think you can run a sub-20 5k in 9 months if you can't even run a sub-32 5k next month" XD

But maybe I'm wrong, would absolutely love to see it and be humbled.

@WilliamKiely 😄 ok you are probably right! ig in my mind 20min and 23min is such a small difference it's like 15%, pfffffft. but maybe not. I ran 19:20 with a fair bit of training but probably closer to 2 times per week than 4. I have the impression that i was not tapped out in the sense that with better or more training i could have been a fair bit faster but idrk