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?
This looks off to me. Do you know what method was used to calculate these zones? I’d say your main issue is your watch is giving you false expectations. I entered your values into a variety of calculators online (age, MHR, RHR) and they all somewhat line up for z2 around 130ish-140ish, maybe 145 max. Between this and the the description of how you feel, I’d say you are far past your actual zone 2. These models are just a starting point. I’m able to breathe comfortable through my nose the whole time in zone 2. If I push too hard it starts to feel like my feet and ankles have weights on them by the end of my run, which is lactic acid build up by pushing into anaerobic territory. Maybe try this lower range and see how it feels?
I wouldn't be surprised. It's the values Garmin gave me when it recalibrated me VO2 max. I'm considering getting a lactate test done to get my actual levels. You might be right though. I probably need to keep the heart rate under 140. Like you, when I get tired it's really my feet and ankles and knees. Not my lungs.