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?
A few things:
Edit: some additions:
5.Your legs getting tired could be a number of things: lactate build up (going too fast),not enough recovery from harder runs/leg strength workouts, muscle fatigue from being unconditioned to longer runs (solution is also to just keep running more and easy).
Thank you for the feedback. Maybe my muscles are just not conditioned for endurance and that's why I'm making slower progress. I'll really consider listening to my body instead of my watch.