I was just wondering like if running keeps you thin?
Basically yes! I do mostly distance running which burns up untold calories and keeps you thin despite eating obscene amounts of food! The best for this is long runs (15k plus). I always do one long run a week, the rest in the 7-12 k range.
And does it make your legs bigger?
Not unless you do sprinting. Shorter distance runners tend to have bigger legs and most do a lot of heavy weight training as well. I also do a lot of heavy weight training (for a woman and for a distance runner) so my legs are bigger than most but then I am short and blocky in build too. As soon as I stop doing weights, everything shrinks!
Also can I ask you your age, height and weight?
I am 43, 5 foot 2 1/2 and weigh between 57 and 60 kg (9 to 9 1/2 stone). I am fairly heavy boned and wide framed - like my hips never go below 38" even when I'm emaciated! I am also quite big int he upper body from weight lifting and I don't have a slim waist - most runners, especially those that do a lot of sprinting don't. So my waist is about 29". Before I did weights and running it was 24-26!
Hope this helps.