If you're looking to improve your #running, the Norwegian approach to sub-threshold training might be worth looking into.
I've read both of these now cover-to-cover and the framework is simple: easy, sub-t, easy, sub-t, easy, sub-t, easy long.
I train by power and keep my CP updated. Unless in a special block, my schedule is:
1. 60' @ < 80% CP
2. 10×3' @ 96-99% CP
3. 60' @ < 80% CP
4. 5×6' @ 94-97% CP
5. 60' @ < 80% CP
6. 3×10' @ 92-95% CP
7. 90-120' @ 80-83% CP

