I'm bulking (1m86cm; 78.5kg). I see my weight goes slowly up when I consume 3200kcal every day and train 3 times per week. Today I did unintentional additional "training" because I walked for probably 10 kilometers and I was very tired when I got home. I calculated that It took additional 300kcals. Should I consume 3500kcals on that day or should I stick to 3200kcal?
no two days are exactly the same in terms of energy expenditure. Your calorie requirement's going to jump around all over the place from day to day.
If you're gaining at 3200 just stick with that. No need to overthink things and start monkeying with it.
So 3200 works for me when I train 3 times a week but my question is when I occasionally do additional training or strenuous activity should I increase my intake on that particular day.
Only you can answer that.
Depends on said activity. Depends on work. Depends on what kind of calories you will consume. And so on and so forth.
Think long term instead of meal or day.
this is what I was getting at. If 3200 calories daily is working then just stick with it.
Don't try and get too deep into analysing it or you'll go crazy.
You are right. I'm trying to hasten things and I might be overanalysing.