Running and lifting

[Larsson1967]

What is the best way to maintain strength in compound lifts while improving running times?
As my bench improves generally my running times worsen and vice versa.
For reference currently I am 86kg at 5’11, can bench 100kg for 7/8 reps and run a 5k in around 23 mins. Three years ago I ran a 5k in 18:40 and would bench 80kg for reps. At the time and weighed about 79kg.
Is it just because I’m carrying extra weight now?
First time post, thanks in advance

[TAWS6]

If you are trying to get back to a sub 20 min 5k your lower body lifts will definitely go down. You can maintain upper body much easier. There’s a few ways to set it up. You need to keep weight on bar the same. As far as programming I’d either go full body 2 days per week or 2 upper days and one lower day. Dieting down would also help but then strength will probably go down as well.

[Horizon92]

Bench press suffers massively from body weight drop. 5K time suffers massively from body weight gain.

At the end of the day, being competitive as a endurance runner is the antithesis to being strong and muscular. If you want to do both, you need to accept that you will not even get close to reaching your potential in either. I can't imagine something more demotivating than that, personally.

Bench pressing will not hurt your running, but gaining weight will - and so will prioritizing time and energy away from running. If you want to optimize for running, you need to focus on base mileage with increased focus on frequency of runs, then adding in so called "workouts" - then let time do its thing. If you want to optimize for strength and hypertrophy, running must be limited to 3 max 4 sessions per week where you're only doing base mileage.

The fact that you will need to gain weight (assuming you are lean) to improve long term hypertrophy-wise will just kill your 5k time and I don't think you're gonna have fun chasing both goals. Pick one and go for it.

[GrouchyUSMC]

What is the best way to maintain strength in compound lifts while improving running times?
As my bench improves generally my running times worsen and vice versa.
For reference currently I am 86kg at 5’11, can bench 100kg for 7/8 reps and run a 5k in around 23 mins. Three years ago I ran a 5k in 18:40 and would bench 80kg for reps. At the time and weighed about 79kg.
Is it just because I’m carrying extra weight now?
First time post, thanks in advance

Could be any number of factors - how often you were running before vs now, form issues, age, etc. more than just simple weight gain.

Being able to run a fast 5k and get strong at the same time is definitely feasible. You just need to program it properly. If you're running 3 times a week with 1 long session of no more than 45-60 minutes and the others much shorter, you won't have any issues doing that while still getting stronger.

[pondman]

You are experiencing the limitation of being human. In my experience running times for a 5k improve when lowering body weight. It helps to be as fit as possible. Lifting improves when increasing body weight. Fitness? Not so much with lifting.