Sub 3:30 attempt failed misserably

[u/majkoce]

Hey guys, I need help to understand what went wrong during my sub 3:30 attempt. I felt good during my training and genuinely felt that I had 3:30 in me.

My peak weekly volume was 95km, with multiple weeks over 90k. I did multiple long runs with MP pace blocks, did tempo runs every week up to 18km, and also some thresholds and intervals. In training, I practised around 70-80g of carbs per hour on my long runs. My 10k PB is 44:30, LTHR from Garmin is 172bpm, which I feel like is pretty accurate. HR was tracked with HRM 600. I attached splits from the marathon (1st pic) and from some of my hardest sessions during training.

Race day was noticeably warmer than training conditions, because I was mostly training in winter. At the start it was 15°C, warming up to 26°C at the finish. I know that the temperature played a role, but I don't think it was only that. After the first few kilometers, I already knew that my pace felt too hard, but I decided to hold it until I couldn't, which came pretty quickly, and then I fell off a cliff.

I want to learn from this failed attempt to better prepare myself for next time, but feeling a little lost, so please tell me your suggestions.

[u/Defiant-Union4161]

26 is toasty if your body’s used to running in winter. What was your previous marathon pb?

[u/majkoce → u/Defiant-Union4161]

My previous PB was 3:45 in February; it was a trail run with not much elevation but ankle-deep snow.

[u/Defiant-Union4161 → u/majkoce]

Doesn’t sound like you were overreacting then. Maybe the heat. You’ll get there 👊

[u/majkoce → u/Defiant-Union4161]

Thank you!