Are lifting 6 days and running 30-40 mpw too much?

You're not doing too much.

I run 7 days/week (1 long run, 2 workouts, 4 easy) averaging around 50 miles/week

I lift 5 days/week on a single body part split (don't take Alan's aversion to this as gospel, he knows a lot but he doesn't know everything), back, chest, biceps, shoulders, triceps in that order with each body part getting the same basic workout of 3 exercises, 4 sets per exercise, 6-10 reps per set, all sets to failure.

Monday: 1.5 mile warmup

8-10x400

1.5 mile cooldown

Tuesday: 7 miles easy

lift back

abs

Wednesday: 7 miles easy

lift chest

abs

Thursday: 1.5 mile warmup

40 minute tempo

1.5 mile cooldown

Friday: 7 miles easy

lift biceps

abs

Saturday: 10 mile long run

lift shoulders

Sunday: 7 miles easy

lift triceps

abs

I'm 53 years old and I can handle this amount of work, I'm sure you can do the same.

Make sure you're getting enough quality protein, If you're having trouble recovering from lifting that's often the culprit especially coming from from a running backround where protein intake isn't emphasized as much. Shoot for .6 to 1 gram/protein per lb of bodyweight, and try adding a serving of BCAA's to your post workout meal/shake.

Good luck.

Some people run over 100 miles a week and do lifting (not heavy but lifting nonetheless) 3-4 days a week.

I'm almost sure you are not doing ENOUGH! What are your goals though???

When I first transitioned to lifting I was lifting for about an hour 5 times a week and running 30-35mpw without much of a problem. My running was VERY easy though (7:45-8:00 pace) with the exception of my long run.

I think 4 days a week is plenty with a proper upper/lower split. Your lifting volume looks fairly high and intense, no need to go to failure so often. At most I go to failure once or twice a week for just 1 set. Pretty much same growth but less fatiguing and fatigue management appears to be your problem.

I lift heavy only twice a week with a third day of explosive body weight work and endurance body weight work.

I just hit a PR Squat of 300 x 6. Previous was 295 x 6.

Quality quality quality.

Alan

I would only lift 3 times a week and not for more than 15 minutes per session.

Be a runner first and foremost. The chicks will come --- don't worry about physique.

I used to be trying to keep Rx for CF and increasing my weekly about 50 at the time and my intensity of running workouts.

Got into worst catabolic fatigues every, my body felt like a furnace for days, and then I would be back... One lasted for 8 days.

Held my running back hugely.

CF isn’t a great idea for a competitive runner. It’s too fatiguing. Doesn’t emphasize strength or explosiveness.

The whole purpose of lifting for a competitive runner is to improve the contractile properties of the muscle, to improve strength snd explosiveness, to improve running economy.

Alan