Mochila para un ultratrail multietapas : Estudio Marathon Sables
La organización del Marathon de Sables acaba de publicar (en inglés) un estudio de gran interés. Analiza los datos de peso porteado por los top30 y los compara con los “paquetes” (Mas alla del top100) tanto de UK como de FR.
Las lecciones que se extraen sobre como cargar la espalda para un ultratrail por etapas son magníficas, por lo que no me pude resistir a colgarlo aquí tal cual en VO:
RUCKSACK ANALYSIS AT MARATHON DES SABLES 2009
Following a study of three categories of runner:
• Englishmen: classified outside the top 100
• Frenchmen: classified outside the top 100
• Leaders: runners of all nationalities classified among the top 30
The average rucksack weight found is:
• for Englishmen: 11.3 kg for 19,200 calories, i.e. 5.2 kg of food
• for Frenchmen: 8.700 kg for 16,800 calories, i.e. 4.6 kg of food
• for Leaders: 7.200 kg for 16,000 calories, i.e. 4.7 kg of food
If we compare the weight of food for Frenchmen and Leaders, we find that there is not much difference, and indeed often less food weight carried by Frenchmen, for more calories. This contradiction springs from the participants’ eating habits.
The difference in food weight between Frenchmen and Englishmen is just 600 g for 2,400 additional calories. This gives a weight of 4,200 kg for 16,800 K/cal.
Englishmen thus appear to find energy products with more calories. They might gain some weight in this area as they rarely repackage their food, keeping original packaging: gain of around 200 g.
Frenchmen could ideally decrease the weight of their food by 400 g.
Englishmen nevertheless appear to carry too much food – some have 25,000 cal. whereas 20,000 would be largely sufficient.
Equipment weight is:
• 6.1 kg for Englishmen
• 4.1 kg for Frenchmen
• 2.5 kg for Leaders
Frenchmen carry more weight than Leaders, but less than Englishmen.
We can note a difference of between 1.6 kg and 3.6 kg with regard to equipment itself.
‘Comfort’ equipment is an area to work upon to decrease weight carried: change of clothes, mattress, stove, camera, MP3, book, etc.
– too many clothes: FAVOUR LIGHT FABRICS WHICH PROVIDE INSULATION.
– rucksack too big and thus heavier: A VOLUME OF 25 – 30 L IS SUFFICIENT
– duvet too heavy: IDEALLY SHOULD BE BETWEEN 500 G AND 1 KG
– cooking materiel, mattress, etc.: NO CUP, POLYCARBONATE SPOON/FORK, READYMEAL, HALF MATRESS…
– large wash bags and towels: IDEAL – PIECE OF SOAP, MINI TOWEL, MINI TOOTH BRUSH, TOOTHPASTE SAMPLE, EVEN A DISPOSABLE RAZOR
The leaders will only have one change of underwear in insulating, high-performing and lightweight material which they keep for bivouac (pants or 2nd pair of shorts, 1 shirt and 1 pair of socks). They wash or rinse their running clothes to get rid of salt; to do this, they must, however, arrive early – also possible to dry during the night…For the evening, they have a sweatshirt or long sleeved shirt and a Tyvek suit.
Note: your cardiac rhythm increases by 20% when you run with a rucksack weighing the equivalent of 10% of your bodyweight. Support changes and the body has a tendency to lean forward. Your feet “slide” towards the end of your shoes. Rubbing increases, heightening the risk of injury to the lower back and shoulders.
It is thus self evident that the heavier your bag, the greater the risk of being hampered by various injuries, in particular blisters. It is thus important to pay particular attention to the weight of each object amongst your equipment.
Your rucksack should not, therefore, exceed a weight of 9 kg for 17,500 Kcal, i.e. 4.8 kg of food and 4.2 kg in equipment weight.
Ideally you should aim to get close to 8 kg for 17,000 Kcal, i.e. 4.4 kg of food and 3.6 kg in equipment weight.
This looks feasible based on the findings for Frenchmen, but drawing on Englishmen for the weight/Kcal ratio and Leaders for the equipment weight…
Easy!!! Start eliminating those excess grams!
Calculators at the ready!