The optimization challenge

When I was studying applied mathematics at school, one of the first famous exercises that I got was the backpack challenge. Imagine you are given a list of items with a 'utility' and a 'volume', and the objective is to fill the backpack maximizing utility. In other words, what is the optimal backpack?

15 years later, I would never have imagined myself to be back in a similar situation preparing for one of the toughest races on Earth. The optimization challenge for the MDS race is actually a lot more complex than the one I had at school for a few reasons:
- some items are mandatory (e.g. aspi-venin suction pump, GPS, mirror, compass, sleeping bag etc...)
- for the food, I am optimizing for the highest ratio calories / weight, knowing I need to have a minimum of 2000 calories per day.
- highest constraint is of course to have the lightest bag
- other optimization factor to take into account is comfort vs weight. Comfort for the nights at the camp: should I bring a light matress, flip-flops, how many pairs of socks? 1 or 2 t-shirts for the week, given nights can be cold (5 degrees Celsius), should I take a cap? Shoe or long sleeves?
Comfort during the race: should I bring hiking poles and protection gloves? How is my light matress going to fit in my backpack and does it move when I run? Should I bring sunglasses?
- though calls: should I take a camera? A GPS watch to track the run? If yes I'll also need a solar battery to recharge them, which means adding more weight...

As you can imagine, what you put in your backpack is not something that you can decide overnight and that takes months of preparation. In addition, it's obviously recommended to train with the full backpack. I'll be sharing in a later post the exact content of my backpack but here are 6 tips that I got in my grams chase in the past weeks and that I'll happily share:

1. A no brainer, assuming you can afford it, is to take the 2 for 1 sleeping jacket (CF picture below). That way you combine in one element the jacket you wear after the race and the sleeping bag which is an extension of the jacket. It's hard to beat that weight (650g)

2. For the food, all meals should be iophilizised. I have even heard of competitors throwing away the package that is sold by default replacing it with zip-sealed bags just to gain a few grams.

3. It's important to know exactly what you'll need and to not take more than what you actually need for the race... And I grant that's you that it is a difficult exercise. For example: you should have an exact idea of the number of gels and bars, or the quantity of sun screen or toothpaste you'll need. Make some tests to check your assumptions!

4. For those who chose to take a light matress, which is my case, remember that you probably don't need the full length of the matress and can afford to cut its weight and even height to 5 feet to cover the top of your body only, which is the most important

5. Make sure all your equipments are ultra light. Pants for the camp (mine is 68g !), plate in light aluminium, plastic fork (6g), ultra light backpack. All this grams add up rapidly. I have personally been taking decisions of what to put in the backpack using excel. Total weight of the backpack should not exceed 10kg on the first day.

6. Going extreme, but every gram counts, don't forget to cut all those ties that are useless on your backpack and to remove those pockets that you don't need, even looking at the packaging of your meals, bars, aspirins etc...