Start with long distance walks to increase endurance. Try interval training by doing higher intensity reps with short recoveries. Something like 2 sets of 4 reps 400m efforts with 60 secs recovery between reps and 3 to 5 minutes between sets depending on how you feel.
Thanx jester I ordered some N2 Burn, looks like it's getting good reviews. Will update people how it goes. I'm looking to lose 9% of my body weight in 2 months as part of a marathon build. Sounds like a lot but it's only 8kg.
Yes I still run in the winter. Winter training is much more fun and important as it is the foundation for your season ahead. I also coach endurance athletes and we do indoor circuits etc in the winter routine. Try skipping for aerobic base if the weather is holding you back from going outside. I...