As far as training for the death march goes you hit the motherload. I just trained my buddy for the event and he kicked ass. When it comes to ruck marches the one thing that everyone knows is this "head down ass up". Whats that mean, it means this suck it up and just keep moving.
The cycle you want to get into is 50 minutues of movement 10 minutes of rest. You have to stick to this even when your fresh and even when your dog tired. After you complete your first race then you can modify this cycle. I highly recomand getting a military alice pack and frame. Then go out and find the most comfortabel straps you can find even if you have to cut them off another pack and then sew them up. Also go get a military ground pad, the kind that rolls up. Cut this thing in small increments untill it can fold up and fit along the entire back of the pack. Between your body and the pack. It will need to slip into the upper frame pocket and between the waist strap and the pack.
Why? first it adds cushion, second you pull it out each and every time you sit down, this keeps you from burning your butt on the hot sand or getting it wet in the mudd. The rest of the ground pad cut it in lengths and add it to the shoulder straps as added cushion.
Now the training, start with one mile and always use 45lbs. First it will make 35lbs much easier and second a 45lb plate fits perfect in the ruck. You can use a sandbag too and put it in the radio pouch of the ruck. If you do make sure you put the sandbag in two garbage bags and then tape the entire surface of the sandbag up with riggers tape.
Do two ruck marches per week, start at a slow pace on flat ground. What you will discover is how much it hurts. Hence the reason we start on flat ground and short distances.
Take your time putting on the mileage, once you go off road then buy yourself a set of hiking ski poles, they are adjustable and make all the difference in the world.
How to don the ruck, crisscross your arms and grab opposing shoulder straps, then in one viloent pull lift the ruck and spin it onto your back. It takes practice, dont wear a watch or it could rip off. Do this with the ruck empty first. Dont ever use help to get to your feet. No one is going to be around to help you so get used to getting up on your own. How? you will figure it out.
Start doing more deadlifts, back squats and lunges in conjunction with the workouts. Do them at light wieght, your form has to be perfect. start with low reps and then add more and more reps. You need your legs and back to be strong and in serious condition. The ruck seperates the men from the mice.
Do not run with the ruck until you can do 4-miles without stopping. Dont go buy combat boots to be hard. Go buy a comfortable high top running shoe or boot. We dont wear combat boots anyway. I wear Asolo's and they keep my feet dry and my ankles from buckling.
Go buy smart wool socks and liners. Wear both, it keeps the feet dry and from blistering. Short nylons under the socks work just as well but they tear easier.
Take care of your feet, if they blister your screwed. Find out were your hot spots are and then buy some blister control pads. They sell then at REI, small peices of plastic you put on before the march to keep the friction down. If the shoes are uncomfortable take them back and get different ones.
Do not go march in low top shoes. Put a camel back or two in the ruck so you dont have to stop to get water. After each march drink a full quart of gatorade very important. If you can handle the taste drink it on the march.
My ruck is loaded like this, 45lb plate, 4-quart sized nalgene bottles, two with half and half gatorade, two with water only, Then I put two full camel backs in the ruck. Yes it makes it way heavier but I drink a ton of water and I used to the wieght.
Every rest break I eat beef jerky, m&ms, and a peanut butter nature valley oat bar. There are all kinds of meals but I am fat enough to live off my reserves for a long haul. I just cant eat very well when I am humping.
I have done some significant humps in my day so I have this down to a science. Most of mine were in combat or training for combat. 45lbs would have been a luxury, usually I was about 135lbs over body wieght. It got lighter as I drank my water and ate but it was always heavy.
Im starting to babble, big thing, humping is just a mental and physical gut check. The ruck cuts into your shoulders and back, your knees hurt, your feet are swollen, your hot while your walking and cold when you stop. It just sucks but its so much fun. Man up-ruck up-and get moving trooper good luck. By the way Ill see you at the march, ill be doing it as well.