Its the technique, you must know the methods of warming up your voice before you sing, methods to project your voice, you want your voice to come out directly from your face? you want your voice to be sounded like sarround system? its all the technique, doesnt mean its Rock, you anyhow strain your voice and spoil you vocal cord, and there's a method to repair your voice after you sang like 8 rock songs? if you apply the right technique , you will feel tireness in your tummy and head, instead off your chest and throat.
Jogging?- good- for your lungs yes very true, but caution- you will have to retrain your voice once you started jogging becoz you will have wider lungs, and u must readjust your voice control, trust me, once you already have wider lungs, you will find its hard to control your voice while singing and reaching high pitch notes, becoz your lungs are much powerful now, its like you install a turbo into you car's engine, now you need better steering wheel adjustment, and you gotta get use to it by driving more often.Thats where proper singing techniques get invlolve here. Best to get a trainer to train you so that you wont spoil you vocal cord permanently, and if you go thru vocal train, you will find there's alot of things that you dont actually realise, how important it is for a singer to go thru vocal classes.

, Chellenge- Two songs that i really wanted to sing without a prob last time were Shes' gone (by SteelHeart) and I remember you(by Skid row), and one song which i think need constant practice on its pitching and now i couldnt really sing it well due to lack of practice on proper techniques - I never let you go (by Steel Heart).
But you must avoid Clove cigarettes if you smoke...