doesn't matter at this stage - just getting the sessions done is all that meters. Building up strength and speed will take time, but take it steadily and you'll get back to decent shape.
Thanks for the words of wisdom! I'm desperate to get back to full fitness again after the saga with my knee, then my broken collar bone and pulled calf muscle. You're right of course - take it steady. I think I'm going to have to slow the cycling down and take it a bit easier to conserve energy when my running mileage goes up.
Balancing the cycling and running will be critical to avoid too much training stress - so maybe easier bike rides and short harder runs as a start?