So once a week I go hiking/walking up mostly hilly terrain for around 3-4 hours. I've looked around Google and it's estimated I burn anywhere between 500-1200 calories whilst doing this and obviously if I don't support this with extra food it'll affect my gains. Just wanted some advice on how to figure out how much extra I should eat on that day? I don't think I'm burning 1000 calories and I don't want to go eating an extra 1000 only to get fat. Also I was looking at using fruit + yoghurt for the extra calories, thoughts? Or maybe oats, milk and whey.