
It's important that you're feeling strong and rested for your Saturday long run. If you're feeling very sluggish or sore on Friday, take a complete rest day.
Fridays: Do a cross-training (CT) activity (biking, swimming, elliptical trainer, etc.) at easy-to-moderate effort for 30 to 45 minutes. It's also beneficial to do overall body strength training at least once a week to build muscle endurance and reduce injury risk. Others are cross-training (CT) days when you should do a cross-training activity (biking, walking, swimming, elliptical trainer, etc.) at easy-to-moderate effort for 30 to 45 minutes. Wednesdays: Some Wednesdays are designated rest days. Or run a few miles at 5k-10k goal pace (tempo run) to test pacing.
If you are feeling tired, it's okay to run at an easy pace.
Tuesdays and Thursdays: After your warmup, run at a moderate pace (slightly faster than your long run pace) for the designated mileage. Rest is critical to your recovery and injury prevention efforts, so don't ignore rest days.