Half marathon PR (1h16) possible off the back of a triathlon season?

Ideally you'd have slightly more time for half marathon specific run training, but your fitness should help obviously compensate significantly.

With the four weeks that you've got, you may want to run race specific stuff for three with a one week taper. You may want to run 6-7 days a week with two workouts and a long run (1:30-2+ hours -- maybe fast finish long runs), with the remaining days at around one hour+ easy pace.

Workouts like 3x2 miles at HM pace with a minute rest, 6-8x1,000 m @ 10kish pace with 2 minute rest, 8x600 m @ 5k pace with 400m jog, and progression runs might be helpful.

Agree with what Georgie says. With that kind of aerobic base, some HM pace tempos between 5-6 miles will give you an idea of what you can run. i found i was faster in the race than in those tempos.

I'd also keep one hard bike workout a week in there if you can manage it. Those trainer workouts that are around an hour of 8 x 3 min hard intervals give you the opportunity to really crank up the HR without pounding the legs.

Good luck and report back.

Thanks, Georgie and Mo, for these quick reactions.

This is very valuable input! Sounds good in my ears. Tough but good. I'd thus have 6 quality workouts and 3 longer runs to go from here, followed by a taperweek in which (mid-week) I would recall the race intensity once more for maybe just 3x1k or so.

Is that an appropriate summary? Better avoid racing in the meantime altogether or is there any particular format that could help boost the race-specific shape?

That sounds like a good plan. I'd replace a hard workout with a 5k-8k race in there with 2-3 weeks out if you can find one - something to blow out the pipes.

I like the sound of that! Thanks a lot!

I think this is great advice.

33-mid open is roughly worth 35:00 in an Olympic. If you're routinely going under 35:00 on accurate courses then maybe there's a little more to gain at 10k but if it's more like 34:50s on courses that might be a touch short then I don't think that PR is too far off from where it should be. Either way, sub-1:15 or even closer to 1:14 would be the equivalent half marathon for those marks.

There's no way around 50km being a limiting factor in pure running. I would say that's somewhat low for 70.3/140.6. Do your best during over the next four weeks to add in some running volume. All of your swimming/biking has you in a good place of fitness leading into the half. Knock out some specific sessions & get in the miles & a solid time will come.

I also think there's really no reason to rush into a half rn. Take some down time & get into your base building phase. You can run a good spring half before the tri season starts off of your triathlon base.

Thanks for your reply! This is a very useful triathlon contextualization and I actually think you might be right about both me being rather close to my 10k all-time-best (as long as I keep focusing on 3 sports at a time) and the run's in triathlons oftentimes being somewhat short to 10k. Unfortunately, I only started using GPS watches about 4 years ago and ever since in OD's I ran rather in the 3:32-3:35 range than below 3:30. I don't think I actually became slower, so what you say figures.

Nonetheless, there must be at least some margin for my 10k running development, even without too much focus on running alone. Why do I believe that? Well, for 3 reasons:

1) all my 34low's were run either crunched between two triathlon weekends (too little rest) or in total off-season (too few specific shape).

2) the current official PR of mine (actually a 34:03) I ran on a correctly measured but certainly not flat course in 2021. 60hm, all packed into the first half (as it was a U-turn course), which resulted in a split of 17:31-16:32.

3) in 2019, I attempted the 10k and definetely had the sub34 in me: on a flat 4-lap course I ran at 3:21-3:23 on all "normal" km's. However, there was one big "abnormality" as each lap (don't ask me why!) we had to cross a church, curving around the benches with sharp 90 and 180 degree turns (and of course, the GPS went wild in there). Each lap, that MUST have cost me at least 5, probably more towards 10s. I clocked 34:07 for 9.96k that day and was devastated. I am pretty confident it was worth a 33:40 but I have never again been able to prove that to myself black on white. (Guess what: the church-crossing wasn't mentioned in any briefing or race description, weirdest thing ever for a competition).

Anyways, much faster than 33:40 seems unlikely. I am not a speedy guy at all. Never went below 2:53 on 1,000m for instance. Thus, speed would be the biggest limitation I think. Volume could be... you are quoting the 50k's but they were really rather the exception. Just checked my yearly avg for 2019-2022 and it was between 34 and 38k.

In my experience, pure running and triathlon running compare as follows: your 5k pace in a SD triathlon is round about the 10k running race. The 10k pace of an OD triathlon is close to the HM running race. And the HM pace within a 70.3 triathlon is close to the marathon running pace. The only values which are not covered by this equation are any pure runs of 5k or less and the marathon within an Ironman triathlon.

Last not least, thanks for the advice to potentially leave a HM attempt for next spring. There is no rush indeed. Last year in autumn I had somewhat of a mental fixation to finally go below 34 on 10k and then got injured seriously, with no running possible for more than 2 months. I won't do that same mistake again. If my legs don't respond well to the first 3-4 key workouts, I'll let go of the HM project for October.