Running

From doing the same relatively recently try and avoid doing more runs at the same pace - I found it increasingly monotonous with no obvious gains in speed/comfort. After a few weeks of a tempo run and a slower long run at the weekend I felt significantly more prepared when starting training for a marathon than I had done previously!

That said each to their own, try a few different things and see what you enjoy

edit: just seen @duncs covered the same in fewer words...

Different volume / intensity of training exercises different energy systems, plus variety keeps things fresh and makes it more likely you'll stick to a schedule (albeit one that will be tweaked along the way.) Best to keep the majority of your runs at an easy pace but maybe make one run per week a "long run" at a very easy pace. If you can get up to one hour or more you'll specifically work on endurance adaptations such as fat burning and mitochondria development. At the other end, a regular weekly/fortnightly interval, tempo session or parkrun will keep things fresh and act as a good gauge of fitness improvement.

I'm still alternating hard sessions using Saucony Endorphin Speed (nylon plate) and Endorphin Pro (carbon plate) to see which I will use for the marathon. The Pros might have edged back into the lead after yesterday's run, a half marathon comprising 22 laps of a local park, which I managed in 1:13:51, working hard but definitely not flat out. Legs/feet felt good throughout, despite a niggly calf recently. I think I may be getting used to the squishiness of the Pro compared with the Speed, and they have got go-faster stripes on them. :)