I did a solo half marathon time trail in 1:29:06 in daily trainers, what could i run in a serious race ?

In a race situation my guess is that you could do between 1:20 and 1:25 in the same course and conditions (and wearing the same shoes). With the given info it's hard to nail it down any closer.

As for the shoes I've heard they're good for 4 percent improvement. Might not be exactly that but it's a starting point for an estimate.

Since you mentioned multiple times that this was a trail run, I would suggest doing your next time trial on a flat road.

Not sure how anyone is supposed to predict that lol.

I'd guess the combination of super shoes plus race adrenaline could knock 1-2 minutes off your time.

Title; Time Trial, not "Time Trail". Okay, got that out of the way...

First and foremost, please keep in mind everyone responds slightly differently to full marathon training. Secondly, LR advice ranges from occasionally sage to fully delusional.

My take is you have a good start. Three-four months of smart training (using a basic stock plan), averaging 45-55mpw, no injuries, and flat course, then IMO 3:10:00 -maybe just a touch quicker - is a reasonable target for (first time?) full.

I would suggest you don't get crazy and shoot for mid 2:50:00s, the results are not likely to be pretty. If you are rolling at 20 miles and feel good/great, you maybe let it unwind a bit.

(My experience: 49+ years running, racing, 18 marathons or longer with a couple of wins and another top three place and some coaching experience)

My understanding is they yield a 4% return in running economy which doesnt necessarily translate into a 4% faster time. I think more likely 1 or 2%.

The 4% thing seems to be widely misinterpreted with everybody thinking it means a 4% faster time and Nike not correcting them for obvious reasons.

^^^^

Obviously the above is for a full. Another several weeks. a decent course, and racing flats; 1:25:00ish? Shoes will help, but it depends on how you respond to them. Look for maybe 1- 1.5% assistance there.

Exactly.

Don't overthink it. Just run one and see what happens.

56:21, I think you're in world record shape

1:26

Sorry, I couldn't help that, I don't know depends on the elevation gained, how muddy was the trail and lots of other variables. But I'd say 1:25 in a fast HM if it was a easy flat trail.

Go run one and find out. Stop asking me to predict your time.

There is a great chance you break 1:30!

I think you can run about 1:24. I feel like a race plus a good course, plus Vaporflys should be worth about 5 minutes vs. listening to a podcast and wearing Pegs.

I did a 1:28 on the roads (with rolling hills) and then dropped to 1:23:40 in a flat race. I was 48 at the time (2021); so I know it holds true for me.

Why would you time trial a half marathon?

It's a big effort that's gonna take a lot out of your body (especially off 30 miles a week). So why waste that on a solo time-trial?

I'm guessing you'll be faster in a race, but not as fast as you think. Maybe 1:26.

Anyone who time trials a half marathon is a moron.

Moran? I think that is a bit of overreach. Since I don't pay to race much anymore, time trialing any distance is my new de facto "race day."

I think races are over-priced and I never know if I'll have people to race with (or if I will be gapped the whole time). I also hate trying to schedule my life around a race. I can TT on days when the weather, family, work, and training all line up.

Time trials are my "races" these days and I can have my buddies pace me (they are faster anyway). I love doing the TT as my hardest effort.

Obviously 1:26:34.78.

No, not a Moran, a moron.

You eschew races and make time trials your races, yet you want to know what you could race a half marathon in after time trialing. I guess by that logic you could race a half marathon in exactly the same time you time trialed it in.

1:28:00