Since starting a full time job my gym usage has stopped. Going to the gym after work means taking a longer tube journey home, and the gym gets absolutely packed in the evenings.
I've walked home from work a couple of times - it's 4.5 miles and enough to make my legs ache a bit. I'm thinking of using walking as my main form of exercise rather than going to the gym. Is walking 4.5 miles 4 times a week a good enough workout to help me lose the 3 stones I need to lose?