I started running at 45 and about 50lbs overweight. I started running using a couch to 5k program with Runnkeeper. I actually did a couple of those because I couldn't increase my running as fast as they were. I paid extensive attention to my stride, and my pace, looking for the forefoot to midfoot landing, more midfoot. (I run in zero drop shoes) During my first 2 years, I lost weight but dealt with a couple of injuries. I found if I was not very careful with my pace, I could pull my left calf. I did it once and repeated the injury by trying to get back too soon. It was a good 3 years before I was able to feel good about my stride and my pace. Shorter strides, with a faster pace, work well for me. Running 10-15 miles a month during the summer, plus a lot of work on the stair stepper in the winter, had me running an entire 5k by year 4 without any walking. COVID, George Floyd, and a family divorce impacting my grandkids has stopped me from having time or energy to run. But I'm still doing pretty good.
July 2016, just when I was starting to run my resting heart rate was 84 with a blood pressure of 125/82
My last visit was3 weeks ago, my resting heart rate is 53 and my blood pressure is 112/73
I'm 52 years old and on no medication. I was essentially sedentary until I was 46.
My suggestion for any new runner, particularly if they have not been a runner in the past is to start slow. You don't want an injury as it'll stop you completely. Do walk run to start. Even if you feel strong, don't push yourself for a good 6 months to give your body time to respond. Regular short runs will trigger your body to respond, strengthening bones to handle the new loads. Building up connective tissues like ligaments to adapt for the new loads you are putting on your body. Let your calves and other muscles get used to it. Do that for at least 6 months. Your muscle growth, your cardio improvements will out pace the bone and ligament adaptation, possibly leading to injury if you don't give things enough time to adapt. Have patience and take it easy.