I've been running for about 10 months now, started in January, when it was about -15 °C outside. Over the time, I managed to lose about 15kg and improved my running a lot, but I always come across the same problem.
I sometimes tend to run too hard. For example, there are a lot of uphills on my track, some of them are really steep. Sometimes I try to run up as fast as I can until I get completely exhausted. But I'm not just exhausted, I can feel my heart pumping so hard, I can feel it on my chest, in my ears, just everywhere.
I don't have a heart rate monitor, but I've been practicing with measuring it on the neck, and I can on average say if it's 1.5, 2 or 3 beats per second, which gives me a rough idea of my BPM. The problem is, that when I stop, I sometimes feel like it's 3 beats per second, or even more, which seems dangerous.
Is there any limit where I should stop pushing myself to prevent some serious injury? I've never been diagnosed with any heart problem, or anything else (I'm 22).
I know that many people recommend running at a pace when I can somewhat sustain a conversation. But I also read, that it's good to practice sprinting once in a while. So I'm trying to mix the usual 5K and 10K with some faster paced uphill sprinting (I know it's not really sprinting).
I don't feel any heart pain when I stop, at least not like I'm gonna pass out, only a little bit. But I can feel the blood pumping really hard and can barely catch a breath. I usually try to run past the point where I want to stop, and just put on the music a little louder and run until the point where I have to stop.
When I add current weather conditions (it's about 5 °C out right now), is training like this good idea to improve my overall endurance, or should I stop immediately to prevent some serious injury?