I am feeling like week 5 is a mountain I can't climb at the moment. 4/2 and 4/3 one of the 5minute runs in both I could barely complete as my legs were burning so much, I was slow jogging as slowly as possible and my breathing was good. This has been the issue every time I've tried to get into running. I can walk 15 miles almost power walking, slam a spin class etc, my CV fitness isn't the issue. My leg muscles just can't seem to adapt to the running motion without so much lactic acid they literally start to seize up.
5/3 looks like a joe right now. Wondering if I should loop week 4 again until the 5min runs get at least do-able!
I feel exactly the same as you... my legs really start to burn and feel tight in the last 5 minutes and I’m really worried about week 5 ...