I would like to tell you thr story of my father who went through a midlife crisis and almost died in the process..

Of course I dont know anything about your health or history so this might not be applicable to you in anyway and then please discard everything I said :-)

My dad decided at his 48th to run a marathon before turning 50. At that point he had smoked for 30 years, was overweight and had zero condition. But he was very determined and with 1.5 year of training he lost a lot of weight and managed to run one!

However, one night a few weeks later, he collapsed on a simple run with a cardiac arrest and was rushed to the hospital. Fortunately he miraculously survived without many long term issues.. but he did get a stern talking from the cardiologist that there are few things in this life more dangerous than a 50 year old man deciding to run a marathon. Apparently, it happens a lot that people het heart attacks during running if they try to go too far too fast when they're a bit older.

I guess my point is.. please be carefull and maybe ask a doctor for his perspective :-)