Mt Fuji as we do it is a single huge push up and back in a day. we start at the bottom and return to the bottom, hopefully via the summit. at its most streamlined its still a 10hr round trip, covering 2500m of vertical gain, and all of it is cold, wind-strafed and upwards. most trips take about 12hrs. add it all up and its a 4500kcal day.
the effort is a constant slow grind forwards and cold becomes the major factor. without adequate kcal intake the chances of topping out are small. now those 4500kcals dont need to be consumed on the mountain. with a 750kcal breakfast, another 250kcal snack in the car and 750kcals waiting for the return, theres about 2750kcals left and less again if you apply the idea that replacing at least 50% will get you thru.
lets say consuming 1500 – 1750kcals over the +10hrs is the goal.
800kcals of liquid energy + 1200kcals of salami, nuts and bars. chocolate coated coffee beans added for the hell of it.
to consume that amount of kcals in that time doesnt happen by chance. a couple of snickers or Clif bars and a bottle of water wont do it. to get it right means a constant flow of carbohydrate into the bloodstream, and after a while replenishment of fat and protein. efforts that long push well beyond what simple carbohydrate consumption serves, not to mention that amount of kcals in carbodydrate form is pretty bulky.
food works best when it is real as the balance of nutrients tells the metabolism and brain it is satisfied or not. gels are fine for a few hours, but aside from solidifying they throw the bodies sense of satiation. carbohydrates in the form of dense bread and quality bars contain a good amount of bang for the weight. complex sugars in the form of dried fruit comes buffered in fiber that makes the brain happy, slowly releases the sugars and gives the bowels something to work on. fats in the form of nuts trickle easily into the system with less of the digestive burden of saturated fats. and salami as a source of protein, extra fat and sodium keeps the body ticking nicely. along with being ‘real’, these foods can be easily found, and picked up 24hrs a day at Japanese convenience stores. 1000kcals from a balanced mix of these things is easy to throw together in a ziplok bag and fits easily in a pocket or top of a small pack.
liquid kcals can come in the form of weight gain powder, endurance concoctions or meal replacement drinks. dumped into a 1L sports bottle its easy to carry 750 – 1000kcals in fluid form. good liquid kcal mixes contain fat, electrolytes and protein in proportions close to what your body will need replacing. you wouldnt want to live on these powders, but for occasional use they fill a gap easily worth their refined natures.
those attempting the Asama-yama-Fuji double header will need to consume like this on both mountains, as fueling (after endurance training – but its too late by then) is the biggest factor towards both safety and success.