u/NotTreeFiddy

I'm running the London in two weeks and it will be my first Marathon attempt. I'm uncertain of what pace to go for. Originally, I wanted to aim for a sub 4, because I did the Oxford half in 1h50 and several calculators suggested the target.

Training hasn't gone to plan due to a mixture of motivation, injury and reduced running on my honey moon.

My longest run has been 30 km, which I did in three hours with a HR of 160. Then, yesterday I did a half-marathon in 2h07. Same HR. I thought I'd do the HM a bit faster, but just felt drained halfway through.

Given my recent runs, I feel aiming for a 4h15 - 4h30 is going to be far more sensible, but I just wanted to get a sense check here and see if attempting at sub-4 would be totally insane.

For anyone interested, here's my last 12 weeks of runs (and my HM from October last year).

Note there is a lack of tempo runs. I play five-a-side football on Monday's and have mostly sub'd them with that. It worked well for me during the HM, but perhaps a foolish move for the full.

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Oxford Half Marathon — 12 Oct 2025 21.23km · 1:50:36 · 5:12/km · HR 177

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Last 12 weeks of running (20 Jan – 12 Apr 2026)

Date	Distance	Time	Pace	Avg HR
2026-01-21	5.73 km	37:22	6:31/km	151
2026-01-22	5.67 km	36:48	6:29/km	154
2026-01-24	8.11 km	52:13	6:26/km	154
2026-01-25	10.03 km	1:00:25	6:01/km	169
2026-01-29	7.93 km	50:04	6:18/km	154
2026-02-01	6.65 km	40:15	6:03/km	152
2026-02-03	5.34 km	32:45	6:07/km	155
2026-02-07	10.02 km	52:34	5:14/km	176
2026-02-11	5.42 km	34:04	6:17/km	146
2026-02-14	14.26 km	1:26:06	6:02/km	154
2026-02-19	16.42 km	1:43:37	6:18/km	156
2026-02-21	5.16 km	30:25	5:53/km	153
2026-02-26	7.85 km	47:40	6:04/km	153
2026-02-27	6.54 km	39:20	6:00/km	153
2026-02-28	18.26 km	1:52:20	6:09/km	155
2026-03-01	7.07 km	46:02	6:30/km	146
2026-03-04	5.68 km	34:17	6:02/km	148
2026-03-07	16.34 km	1:55:26	7:03/km	150
2026-03-15	20.04 km	1:58:39	5:55/km	148
2026-03-26	10.75 km	1:01:42	5:44/km	158
2026-03-29	27.70 km	3:07:44	6:46/km	152
2026-04-02	9.54 km	57:09	5:59/km	161
2026-04-04	30.02 km	3:00:05	5:59/km	161
2026-04-05	5.08 km	40:36	7:59/km	124
2026-04-07	7.95 km	49:46	6:15/km	153
2026-04-09	10.50 km	1:04:10	6:06/km	152
2026-04-12	21.13 km	2:07:14	6:01/km	160

ETA: It's perhaps worth noting that the London race will be significantly flatter than my typical runs.