Geoff Hamilton ~ Presenter of "Gardener's World" for many years and famous for creating "Barnsdale" garden had a heart attack, despite being a non smoker and spending every day gardening and working. He was a fit man but he decided after the HA to buy a bicycle and "get fit". He died of a massive heart attack whilst cycling.
The man who invented the Jogging to get healthy craze (A Yank by the name of Jim Fixx) died at the end of a jogging session at the age of 52 of a Heart Attack.
You are now 49 ~ accept that as a fact and do not try to turn back the clock ~ believe me it cannot be done.
Sell the bike and use your car to get around. You know it makes sense.