How do I stop myself running 8 minute miles all the time?

You stop yourself from running 8 minute pace by either not running or running at a different pace. 8 mins seems fine for your easy pace. Are you asking for training advice? Go back to 50 mpw and add another track session a week - so 50 mpw with 2 workouts - your 5 to 6 mile tempo and a session of 6-8 800s on a track at 540-550 pace with a 400 jog in between. Come back when you run 1759.

you do speedwork where you feel faster in general. you do intervals at a shorter distance as a faster speed where you get used to a quicker pace. something not "grooved" at some safe, comfortable pace.

this is also where (a) doing some group workouts or (b) racing regularly might help. competing or trying to stay with someone will drag some more speed out of you. or conversely getting your butt kicked running slow will motivate you to go faster.

also, think about it like this. this is not the state track meet or conference. this is your umpteenth training run. there will be another one in 1-2 days, and after that, and so on. you aren't ruining running or your big meet if you tinker with pace some days, try and push it. you blow up or end up walking or something, you learned something about yourself.

8min pace feels generally right for easy miles for someone at your level. Incorporate strides into your training weeks & think about 1-2 workouts/week. It's even unclear how you structure those 5-6 miles on a track or straight section of road. Do workouts with distinct warm ups and cool downs. Fast running can be continuous, but, for a runner like you, do workouts you wouldn't normally do -- shorter reps w./ more rest (even standing rest). That'll force your heart rate to come down & give you the legs to push. In your long runs try some tempos or fartleks just to mix it up. An 18-low 5k runner could be a sub-3 marathoner. No reason you don't do some work @ 6:30-7min pace.

I ran 7:30–8:00 on almost all my easy runs for many years. I ran well under 2:00 and 4:20 for the 800 and mile respectively, and under 16 for a 5,000. Usually around 40–45 miles per week.

The only time my easy pace got faster is when I trained for a marathon and did 70 mile weeks. I was closer to 7:00 on my easy days after all of that.

What you can do is right before you get to each mile marker just put in a quick surge and maybe even a line dip (just for practice). BOOM! You're now getting in 7:59 miles and have effectively cheated the 8:00 per mile matrix.

The 8 minute miles aren’t your problem, if you want to get faster than 18:00 you need to implement workout days. 8:xx miles will train your aerobic engine but they won’t train your speed or anaerobic endurance which becomes more and more necessary the faster you get at 5k. Most people feel a considerable shift in running mechanics somewhere in that 5:30-6:00 per mile range and you need to prep your body for that. You’re doing the equivalent of doing a ton of push ups and only push ups and expecting your maximum bench press to increase.

Heres a few good ones:

6x800m in ~2:50 w/ 2:30 rest or 400m jog recovery

12x400m in ~1:20 w/ 1:30 rest or 200m jog recovery, 3:00 or 400m jog recovery after every 4th rep if needed.

8x200m in ~0:35 w/ 2:00 rest

10x30 second hill runs w/ walk down rest

1:00 hard 1:00 easy for 30-40 minutes

get bigger to 300 lbs

You need to have some discipline. Go.......

Run downhill.

Run faster (or slower). Your choice.

Cut off your feet

Get a training partner, preferably someone faster than you.

Practice running on pure hate, or imagine you're being chased by a bear.

Also hills and strides.

I wish I still had that problem.

Wish I still had that problem.

The Easy Answer: Run faster.

The Complicated Answer: Running is Stride Length x Stride Frequency. To run faster than 8min/mi, you need to increase both of these things in proportion to each other.

Make a conscious effort to move your legs faster, it really is not that difficult. You're not moving the needle from 8:00/mi to 4:40/mi.

Warm up before your run. Stop. Do some strides and drills. Take a pit stop if necessary. Then do your run. It will be a lot faster. The key is to be fully ready when you begin your run. And have a purpose in mind for each run. It's not complicated.

Simple: run 7:59:59 per mile.

Or 9:00!