Why are you running 6 days a week? Your big issue appears to be doing way too much. This will only led to burnout or injury. 3 days a week is enough for improvement - interval session, tempo run and distance run. Add more days in as you get more comfortable.
Interesting discussion. For my first two marathon I ran on average 4 days a week, these runs were not focused on quality but getting in the miles. First marathon went out too fast the first 15 miles and ended up walking part of the last 6 miles out of exhaustion. At this point 9 minute miles was what I would have condsidered too fast but was my ultimate aim. My times in both these marathons was 4:21.
The next year I brought the training sessions done to 3 days a week. I did a fast tempo session, a challenging tempo session (some hills) where I tried to run at least 7 miles in an hour and the weekend long run.I also did most of my runs with someone fitter than me which was a substantial benefitI for me as they pushed the pace. Despite marathon day being one of the worst days of the year with wet weather and strong winds I came in at 3:56 and knocked 25 mins of my time.
Fast forward to this year and I had the same plan as last year only over the previous 6 months had dropped nearly 3 stones (From 15 to 12) and very much focused on spped. I was very hard interval sessions and running some of my long runs way too fast (7:30 miles). After doing a good half 1:36 I set the bar for my marathon to 3:30 however disaster struck 2 months from this marathon. I kept getting runner's knee, an issue that never really affected me the previous 3 marathons. I would say this was mainly caused by doing too many fast sessions although partly because of overused trainers.
I ended up not getting in as many long runs as I hoped due to this injury and although I ended up knocking 20 mins off last year and getting 3:38 I was disappointed. The feeling I had of hitting the wall at mile 20 was the worst I have ever had in any of my runs. I seriously thought about giving it up and walking home. My pace the first 20 miles averaged just under 8 minute miles but by this stage I was hitting 11 minute miles and struggling. The last 10k took me 65 minutes. This was down to a lack of long runs 18 miles and above due to the knee injury. So if you go for the quality trainings be sure not to make all of them them too fast.
The more and more this saga goes on the more I see it as a massive wind up of some kind! Tom says he spoke to a doctor, he got hold of one very quickly, it takes me 4 days to get an appointment on the NHS, of course he could just happen to know a doctor...
I think this whole thing is fabricated or Tom is already an elite runner looking on race day to run sub 1:10-15 and then claim he did it in 16 weeks. What's to stop an elite runner go out and run on purpose 22 min 5ks?
Johnas currently doing this interval work, a long run around 8:30 pace about 10/11 miles and a tempo run where averaging 7:10-7:20 pace usually about 8 miles. I don't want to start adding more miles to the long run just yet as marathon is not for another 4 months. Will start increasing a mile a week in July. I try and do another run in the week and maybe some weights work. Walk probably 30 miles a week on top of this.