I was supposed to run the Manchester Marathon on the 19th April as my first marathon.

The training had gone really well, but I came down with a virus with 10 days to go. Had it been a mild cold I might have had a chance, but actually it was the worst viral infection I can remember having. I'm now almost three weeks in and still feeling the effects.

So the marathon didn't happen. But there is still value in reviewing the training process, which went well generally but with room for improvement.

What did work out:

1. Niggles/injuries held up. My core S&C consists of bulgarian split squats, seated calf raises, stability ball rollouts. These are the most time efficient and running-effective exercises that I've found so far.
2. Long runs went fairly well and I completed four runs over 30k, in the 2.5-3hr range. I didn't have the fuelling worked out on the first one, but I got it much better on the next three.
3. Long interval training had a good effect. I spent the later part of the block aiming to do Nx4k (1k recovery) once per week. Illness interfered with this somewhat, but in the peak week I completed 4x4k and unintentionally ran a half marathon PB somewhere in the middle of that workout.

Overall, to begin with I was quite apprehensive over my ability to actually do the distance and keep a pace, but by the end of the training block there were no doubts whatsoever.

What didn't work out:

1. In the 7-8 weeks before the marathon I ended up catching 3 separate illnesses. The first was a mild cold, the second was a stomach bug and the third was the big one. The first two didn't stop me running for long but lingering effects did make me swap a few quality workouts for easy runs. I think I was just unlucky with this - I'd gone about 12 months without being sick and then got 3 viruses in the space of two months.
2. My training load didn't get as high as I really expected it to. It was just condensed into fewer and longer runs. The recovery from the 30k+ runs led me to take more rest days than I expected. But I found that my recovery on the later long runs improved, which means my body adapted and/or the better fuelling helped.
3. In the last six weeks or so I ended up cutting out interval sessions faster than threshold, just because I couldn't tolerate a long run, a long interval and a fast interval session in a week.

My metrics for the training block looked like this:

The load ratio dips a lot as a result of illnesses but was mostly in the right area other than that. The long runs pushed it briefly into warning zones but only for a day. My HRV was a bit suppressed throughout most of the block, and seems largely decoupled from the training load, so I don't think it was a sign of overtraining. I found this hard to interpret at the time. I think it probably most correlates to viral infections, which means it probably actually inversely correlates with training load over much of the period, whereas it would be the opposite over a healthy period. Heart rate follows a similar pattern to HRV, but recovers faster after viruses.

The viral symptoms started on the 11th, but HRV and HR knew something was up on the 9th. Now, the HR looks mostly recovered whereas HRV is lagging a little bit, which is normal but means I'm not 100% recovered. Both are still a bit twitchy. I've opted for total rest for all this time, because 1. I felt pretty bad, and 2. I'm concerned about post-viral issues/long COVID, but I'm going to begin testing the waters now with some very gentle bike sessions.

Not to be defeated, I've signed up for another marathon in October. The road to this one will be via half marathons in August and September.

So, plans for this next round:

1. It turns out I'm vitamin D insufficient (which is the space between deficient and sufficient), which might explain the illnesses, especially on top of a demanding training load. So I'm supplementing this.
2. Fuelling - fuelling worked out pretty well, but I'd like to try to get my body used to taking in even more. My general strategy for the 2.5-3hr runs was 2x Tailwind + 2x SiS beta gels, which is about 180g of carbs in total or 60g per hour. That's the generally recommended figure for the average person, but elite runners will take on about 90-120g per hour and they train their stomachs to handle it. So it's worth practicing shoving goo into my mouth. Tailwind is a bit complicated because it ties fuelling to hydration, and perceived hydration needs vary substantially with conditions so I had to force myself to drink sometimes when it was cooler, but it seemed to work out.
3. I'd probably benefit more in terms of scheduling to merge the weekly long interval workout into the long run. Maybe not every week, and it might pay to try to hit the 30ks earlier in the training block so that the earlier long runs are long slow runs then they become interval sessions later in the block.
4. ...because this would leave me able to do a faster interval workout too. I feel that faster sessions are great for running strength and economy and I lose something by cutting them out, even if 400m intervals aren't obviously applicable to a marathon in terms of endurance.
5. Add volume on the bike. I didn't feel like running the day after a long run, but I could have tolerated a 30 min bike session and it might even have helped my legs recover.

I just need to start off gently before I ramp it back up again. I'm feeling optimistic.