I only really just returned to the gym so long way to go.
I start with a fast walk then set my times for a run. then wait for the next bit.
Started off 3 mins walk 2 mins run and over.
then the week after 2 walk 3 run and so on.
I have had to invest in some wireless headphones as the wires do my head in and I am not fond of the thumping gym music.