Swiss International Mountain Marathon


Photo: Daniel Vonwiller

The Swiss International Mountain Marathon is a two-day event inspired by the UK’s Original Karrimor Mountain Marathon (now the OMM). Teams must be totally self-sufficient for the two days of this race, which first took place in 1976. A good night's sleep can make all the difference to your results, so you'll need to choose a sleeping bag and clothing suitable for alpine summer nights at around 2000m.

Sleeping bag choice

The two PHD sleeping bags most suitable for the Swiss International Mountain Marathon are the M Degree 200 and the M Degree 250. Both are very lightweight. The M Degree 200 excels at saving weight and bulk in your pack, while the M Degree 250 provides extra warmth. Otherwise, the Superlight bag on our Design Your Own Sleeping Bag site allows you to create a bag of exceptionally low weight to your own specifications.

For even more weight saving, consider a hoodless sleeping bag. The Delta Race 200 is one of the most extreme lightweight bags ever made and will combine with the buff or woolly hat you already have.

For mountain competitions, particularly where only one or two night's camping are involved, there is a strong incentive to travel as light as possible. Combining the M Degree 100 sleeping bag (or the Delta Race 100 sleeping bag) with down clothing - such as our Wafer Ultima Pullover (adding 5°C of extra warmth) - is another potential option to secure a good night's sleep.

The basic figures for the standard models:

S-bag TOT (Min Temp) Weight Packed size
Hght x Diam (cm)
°C  °F gm oz 
M Degree 100 10 50 240 9 21 x 13
M Degree 200 4 39 340 12 21 x 13
M Degree 250 0 32 390 14 21 x 13
Delta Race 100 10 50 200 7 18 x 10
Delta Race 200 4 36 300 11 21 x 13

Additional points:

TEMPERATURE RATING: Put simply, these are the temperatures at which you should be able to get a night's sleep in normal circumstances. We have more information on our temperature ratings in this Technical Briefing.

LINERS: A liner will add to the insulation, but as always there is a trade-off between the extra weight and bulk, and the warmth you gain. Silk liners add roughly 2°C but only weigh around 140g so they’re a popular choice. If you’re especially concerned about cold, our K Series Filler Bag is 100g heavier than that but will add an impressive 10°C.

CLOTHING: Thermals (if you are taking them) and/or other clothing obviously help to keep you warm. For example, an outfit of Wafer clothing will give a 5°C boost to the temperature ratings of our bags.

FABRIC OPTIONS: The M Degree bags come as standard with 7X outer fabric - a mini-ripstop nylon with excellent tear-strength - but are also available in Hypershell, which is highly wind/water resistant but only adds about 15g to the total weight. The Delta Race bags are made in the even lighter Vertex fabric. Each of these bags are also available with a waterproof footbag (racing tents can be pretty cramped and it’s easy to end up sleeping with feet pressed against wet fabric) that can be ordered either permanently fixed in place or detachable to allow stripping down for ultralight overnights.

ZIPS: Zips are an option, but most competitors don't ask for one. A short zip with draft tube adds about 50gm (2oz): a full zip and tube adds about 110gm (4oz). Zips also add to the packed size. A further option is the footzip which only adds about 10g (⅓ oz). 

PACKED SIZE: PHD stuff sacs tend to be on the loose side. All these bags can be compressed further in your pack.

Clothing selection

At the campsite, at the end of a day's racing, the drop in temperature can be very noticeable, making warm, compressible and lightweight clothing extremely useful.

The race's kit list specifies a warm mid layer for cold days or at camp in the evening. The Wafer Ultima Jacket or Wafer Ultima Pullover will provide warmth down to round about freezing point, but weigh just 185g/155g respectively. If you really tend to feel the cold though, then the Ultra K Jacket or Ultra K Pullover have also proved popular on mountain marathons, offering a fantastic level of warmth at what is still a very low weight. They have a typical operating temperature of -5°C but nevertheless weigh just 240g and 225g respectively.

It can get damp out there, and synthetic insulation tends to fare better than down in the wet. Carrying waterproof clothing is compulsory, so you should be able to avoid saturation, but if you prefer the more failsafe, less moisture-sensitive option of synthetic gear, then our Sigma gear is well worth a look.

When layering clothing inside your sleeping bag, make sure you don't neglect your feet! A pair of Wafer Socks weighs just 45g but makes a huge difference.

The next Swiss International Mountain Marathon will start on 13th August 2022:

www.mountainmarathon.ch