The target pace on the sign up form turned out to be a range so i went for 3:15 - 3:45, which feels pretty generous but i'm not going to complain. I do plan to do some Daniels-esque intervals, maybe for the Wednesday session from Higdon, but i want to keep my overall running mileage relatively low to start out with and rely more on cross training to try to reduce the risk of further injury.
If you are worried about injuries then I definitely wouldn't do any intervals or speed work, and in general keep paces slower than suggested b various pace calculators.
Weekly millage is actually only very slightly correlated with injury incidence until the weekly millage gets very high, e.g. 90+ miles per week. Injury risk is more strongly correlated with:
- Poor Technique/form
- Poor shoes/worn out shoes, badly fitting shoes
- Over-training, insufficient rest and recovery periods
- Fast pace running, intervals, tempo runs
- Increasing millage or days running too quickly
If I was worried about injury then i would drop all speed work, slow down, and very slowly increase weekly millage to allow adaptions to occur that will strengthen bones and joints. I probably also wouldn't worry about racing a marathon and instead spend a year increasing base millage. But I really like having a goal so I probably wouldn't head that last piece of advice! But seriously, running too fast and any form of intervals puts far more stress on joints and bones. you want well placed, light foot-steps maintaining good form and posture, correct cadence and good foot strike. People can run 100 miles in a single race and get little more than DOMS, running 100 miles over 6 days is much less stressful. Ultrmarathon achieve that by running slow.
You get a triple whammy improvement going slow :
1) Slower speeds means shorter strides and less vertical oscillation which reduced impact forces.
2) You don't get so tired to maintain better form which reduces stresses
3) Most of the adaption required to do well in a marathon occur at slow speed, such as increased capillary formation, improved ability to metabolize fat, increases in mitochondria, improved slow-twitch muscle density.