Lifelong athlete. 37yr old male. College baseball player. Have been lifting weights for 15 years. Very consistent with my diet, in fact I have my diet dialed in and track calories eat nothing but whole foods.
I've been running for over a year, off and on due to calf and achilles injuries but mostly on. I am on week 10 of a 20-week half marathon plan.
If you look at me, I look very fit. People assume I am very fit because I have decent muscle mass and I'm pretty lean (around 10-11%bf right now). But I really struggle running. I just ran a 7-miler for my long run and it killed me. A freaking 12:53 pace, started at 5am and finished around 6:30am. I am deliberately running in zone 2 to build my endurance base using my Garmin watch and chest strap. I couldn't have run any faster if I wanted to. Running so slow but my average heart rate was 149bpm. All of my other health factors are very good. 48bpm resting heart rate. 7-8 hours of sleep a night. Weight lifting 3 days a week. Running 3 days a week. All blood work in January was great.
Before I focused on my endurance I got my mile time down to 7:33 at around 80-90% effort. I just feel like I should have a better base by now and even though building the mileage takes time I feel like I'm way too slow for how long I've been running.
Am I doing something wrong? Any advice or feedback for me?
The only thing I haven't seen people mention so far is breathing.
Make sure you are doing breathing exercises and that you can keep your breathing under control for your whole run. Once your breathing goes everything else will fall apart.
High heart rate and "struggling" makes me think this is a likely underlying cause.
Does "struggling" mean burning lungs and side stitches? If so it's certainly this. If it's just muscle fatigue it might also be hydration or electrolyte shortage.
Quick links on how to improve breathing while running: https://marathonhandbook.com/how-to-breathe-while-running/
My lungs aren't burning at all. I have my breath still, it's my legs
Maybe it's your fast twitch vs slow twitch muscles composition? https://blog.nasm.org/fitness/fast-twitch-vs-slow-twitch
Hard to say since you state you do other activities that would usually indicate a balanced ratio, but form of those activities can influence whether one type or the other is preferred in muscle growth... You did say sprinting short distances isn't an issue, when you do weight training is it burst lift or slow reps?
Genetics is a big component because you most likely developed a form complimentary to your physique, meaning you do faster lifts and fewer sets because you have more type II, which then encourages growth of type II. Nothing wrong with this form or exercise approach, but it means you're adapted to bursts of activity instead of longer duration activity. So it'd take a longer timeframe to try to retrain your muscles (if you'd even want to).
Hard to diagnose over an internet forum, a qualified trainer should be able to advise better
Edit: actually looking into it more, baseball is a sport that heavily prioritizes fast-twitch. If you trained for that in your formative growth years you likely do have an imbalance favoring type II over type I. Again: Check with a trainer over an internet stranger. But adjusting your strength training to favor typeI development could yield benefits to your distance running... That would require a multi-week period to see changes though :(
Very interesting. Thanks for the feedback.