I'm fairly new at running. I really enjoy it but definitely wouldn't consider myself very serious about it. I ran a couple 5k races and a 10k race last year. I'd like to increase both my 5k and my 10k pace and also prepare to possibly run a half marathon later this year. What types of cross-training would be effective in helping to increase 5k/10k pace as well as the pace I'm able to run at in general?
What are some of the more effective types of cross-training for increasing running pace?