Sorry for opening yet another sub-5 mile thread.
28 yo, male, running inconsistently for about 10 years, more seriously and consistently since maybe 2018.
Same situation as many other people, pandemic, no competitions, trying to find motivation, let's try a mile. My goal is to try to run it before Christmas, so far, since August, I've been running mostly what I'd call base training.
A couple days ago I went to the track for a faster workout. I ran 9x150m "fast" with a 2' jog, then jogged a lap and a half, then I ran 4x200m. I was feeling pretty fresh when I started the 200s. The first 200 I ran maybe 32s, the second one I pushed harder (I'd say it was max effort, but maybe I didn't accelerate as fast as possible at the start) and I ran 31.xx, timing myself (so I guess I can be about a second off), the other two were also as hard as possible and din't break 32 again. Maybe if I'm fresher and I run "harder" I can run sub 31, but I see sub-30 very far. Since I am trying to break 5 for the mile, I think my lack of speed may be my greatest limiter.
So my question is: am I too slow to run a sub-5 mile? How would you approach training my speed, to be able to run a 4:59 mile?
More context: To get an idea of my talent, I ran a 40:05 10k when I was 19, took me 3 or 4 years of inconsistent training to run 39:59. Another year and a little more consistency took me to a 39:30 and some more consistency led to 39:18 in december 2017.
Didn't race for almost a year after that. In fall 2018 I slowed down my easy training, had the most consistent three months of training of my life, running about 50 mi/80km per week for 5 or 6 weeks, including a couple workouts per week, fartlek and tempo type, not too hard or specific, surprised myself running 37:55 in December 2018. I didn't expect at all to have that fitness, I think I could have gone a few seconds faster. Stayed consistent and two months later, February 2019, I ran a 5km in 17:29.
I kept my training relatively consistent, running an average of 58 km/36 miles per week in 2019 (including some breaks of less than one week) plus about 290 km (180mi) of backpacking, totalling 125 hours, most of them in August (when I didn't run much). In December 2019 I ran another 5km race in 17:29, it was a local race and 17:29 was enough for 3rd, no way I could have caught the second, and I finished with the feeling that I could have gone longer, but not faster.
During the last few months I've been running consistently. I've averaged 82 km/week for the last 8 weeks, I do a fair bit of my running on trails with lots of uphill and downhill, for example my long run is two hours on trails and I get 21.1km with 400m (1200ft) of vertical. Equivalent heart rate on the flats would probably get me 24 km in those two hours on the flats.
My normal weekly schedule, which I would call "base" has been: long run on Sat or Sun (about 2h), 2 workouts on Tues+Fri, normally one tempo (10km in 40min, for example, or progression run) or a fartlek (1 min fast/1min moderate, averaging about 10km in 40-41 min). The other workout has been either longer reps (1km-2km, 8-12km total, effort 7-8 out of 10) or shorter reps (16x400 in 1:24, 35s rest, felt I could do at least 4-5 more). I've also done 2 workouts of 150m -200m fast, to work on speed, and that's how I realised how slow I am. The rest is easy mileage, normally running 7 days a week in singles, rest days as needed, 2-4 of those days are on trails with elevation, including the long run. I should probably do more strides, and this may be the first step to getting faster, I never seem to find the time to fit them after my easy runs.
FWIW, another thing I noticed: last time I did the 16x400 workout I did them averaging sub 1:24, with 35s rest. I was happily surprised, because I used to do them in 1:26-1:28 before I ran 17:29. I had the feeling that I could have kept going for a few more and it wouldn't have been a race effort. However, I decided to do the last one (number 16 faster). I ran 1:18, and it felt much, much harder, for what I'd consider a relatively small change in pace (especially taking into account that I want to run sub 75s per 400 for 4 laps). I think that to run another 1:24 after that I would have needed 2-3min of rest. I don't know if this information is useful, but it may be. The workout makes me think that I may be in about 17:15 shape, comparing it to what I used to do when I ran 17:29.
If you got to the end, thank you for reading. And again, my question: Am I limited by my speed? What can I do to improve it to the point that I'll be ready to run a 4:59 mile?