sub 49 400 and sub 3 hr marathon

Thousands of people have done this.

I imagine Rupp ran a 49 second 400m at some point. I'm sure Bekele, Geb, and Farah all have as well. Pretty much anyone who had a successful track career and then became an elite marathoner would have that combination of speed and endurance.

Any professional 800m runner in the world can do this.

I imagine anyone capable of a sub 49 400m could jog a sub 3 marathon with a couple years of aerobic training. More interesting would be within a week of eachother, but it still feels like the sub 3 marathon is the easy part of the equation.

Sebastian Coe - 400m PB 46.74, marathon for fun after retirement in 2:56 (1991)

a more challenging feat: run a sub-50 400 and sub 2:30 marathon in the same week. probably most elite milers could do this but not sure…

I think just about every pro caliber and many upper collegiate caliber 1500/5k types could do this in a 4 hour window. If you are running a 10-12 mile steady state run at 5:20 pace or faster, putting up 70 mile+ weeks, and running sub 3:40 and sub 13:30 you can run the 400m and then have a bit of an overkill cooldown afterwards. 6:5x pace is a very easy jog for that type of athlete, they probably wouldn’t even experience a bonk due to low energy demands at that pace. I had a teammate with really solid range who I wouldn’t even call a top collegiate who ran a 49.x relay, 1:52, and 3:48 1500m who was putting up 13-16 milers at 5:30-5:50 pace every week. After he graduated he trained for 4-5 months for a marathon and went under 2:30.

This is incorrect. Most world class 5000m runners cannot run 48xx for 400m. Even many world class 1500m runners cannot run 48xx for 400m.

Ran 45.4 relay leg and 2:54 marathon, also 35 min 10k on roads.

David Gillick Ireland 44.77 National Record 2009 and 2:58:59 Dublin Marathon 2023.

I'd imagine the Sub 45/3 Hours club is small!!

I’d be impressed if someone did this in the same race, especially if the last 400 was in 49

It's a weird comparison because sub-49 is so much better than sub-3. Most sub-49 runners could do a sub-3 if they trained for it.

The suggestion upthread of sub-50 and sub-2:30 is more interesting.

Steve Cram
49.1 400m 1982

2.35.44 marathon 1999