Some background info: I am 28 years old, about 177 cm tall and my weight fluctuates between 92-96 kg. Despite the unfavorable height/weight ratio, I am pretty heavy built, with wide shoulders and a broad chest. While I would not consider myself really fit or strong, I am also not really out of shape.
I spend a lot of time in front of a PC at work and at home. That being said I try to train at least twice a week; primarily playing football (indoors or outdoors) and try to work out at the gym on a regular basis (even though I cannot claim to have good discipline). I recently got introduced to the idea of obstacle races such as (Tough Viking, Warrior Dash, Spartan Race...) and come to like the idea. Especially setting the goal to finish such a race before I turn 30 in two years.
I do realize that these competitions are tough, and that they are aimed primarily at training-enthusiasts that invest much more time and money to their training than I do. However considering that I don't care about the racing aspect of it (i.e. I dont care my "time", but only to actually make it to the end without giving up), I think it's still a reasonable goal.
My specific questions are as follows:
Is 12 months too little time to train for such an event, assuming I do not drop focus on my work and social life? I like training, but I cannot allow training to take over my life altogether.
I am concerned about my shoulders and lower back due to previous injuries, while I do not have any limitations in my daily life, I wonder if participating in such a race would be too much of a risk. What are good exercises for shoulders and lower back, considering the type of wear they will face during such a race?
How important is condition in such an event? I usually get tired after running straight after 20 mins, but in interval training (e.g. football, squash etc) I can keep going at it for more than 1h without any trouble at all. Would this be an issue?
EDIT: I have mentioned that I have had several injuries without explaining what they are... I have had serious problems with my shoulders, as both have been dislocated more than once. I have been operated on one shoulder and have some rotation limitation (about 5-10 degrees on outwards rotation). With my weight it gets pretty painful in both shoulders, very quickly, when I attempt to do proper dips and pull-ups
With my lower back, I have had less but still painful problems, due to relatively sedentary life as well as some weird movement I did on the football pitch at some point. I have some sort of minor issue with discs but they doc said it wasn't serious enough for a surgery. I pay more attention to stretching and try to be more active during the day (at work that is) in order to help with that. Hope that helps to give a better picture of my physical situation.