Buyers' Guide - Outdoor Undies

You've spent thousands on your sophisticated layering system - you have hardshell, softshell, eggshell, mid-shell and more, but hey, strip it all away and there's a good chance that lurking underneath is a nasty pair of cotton shreddies holding moisture close to the skin and stopping what's on top from working properly.

Yep, it's a strange thing, but many outdoors people hardly give a second thought to their underwear, but it's worth investing some time and money on your outdoor undies.

It's the same theory as baselayers. To stay comfortable, you need to move moisture away from the skin and while cotton may be fine for day-to-day wear, for active use it's hopeless, tending to hold moisture next to the skin.

That means discomfort but it also prevents the layers above from working properly. There's no point in wearing, say, a high wicking pant and overtrouser if the sweat from your body is trapped in your underwear.

The same factors that apply to baselayer fabrics are equally applicable to both knickers / underpants and sports bras - more of which later - but with one essential extra requirement, because of their location, it's very desirable to use a fabric that has some sort of natural or added anti-pong property.

The main synthetic options are polyester and polypropolene. Polyester, the most commonly used synthetic, is generally good at wicking moisture outwards away from the skin, while polypro - used by Helly Hansen and the North Face - is hydrophobic, which means it forces water away from itself. In practice, both are signicantly better than cotton.

On the natural front, merino wool is another option. It can absorb lots of fluid without becoming uncomfortable and has good anti-pong properties. It doesn't wick as well as a good synthetic, so if you're really sweaty it might be best to look elsewhere.

Finally, silk works well too, however it's expensive and not particularly hardwearing.

There's only so many things you can do with your humble shreddy. For fellas that means a choice between a longer-cut trunk or boxer short style or a more brief-like design.

Our experience suggests that trunks are less likely to chafe during walking and a close-ish fitting trunk arguably offers the best combination of wicking and comfort. Baggy designs won't contact the skin as thoroughly, which will compromise wicking.

Women on the other hand, tend to have a choice of briefs or briefs. The key in both case is to avoid anything that feels like it might cut into you uncomfortably - top or bottom - but is snug enough to avoid sagginess and slumping.

What else? Make sure there's a fly if you want one and, if you're sensitive, be aware that some brands, notably Helly Hansen, produce windproof fronted briefs to ward off icy winter blasts.

If you're an active sort of lass, you probably already have a vast selection of sports bras, but here are some basic pointers.

Fit is crucial, so if you're in any doubt about your correct bra size, either measure it yourself or get it done by an expert.

You need to choose the level of support your bra offers according to the impact level of the activity. Walking is low impact, but running off road is high impact and requires more support to minimise breast movement.

Build type may be related to support. Compression-type bras pull the breasts fully in and are best suited to smaller cup sizes. Larger breasts are more suited to natural shaped bras which offer extra support and may incorporate underwiring to provide extra support.

Styling is another consideration. Some tops are designed so they can be worn both as under or outer wear and are generally more generously proportioned; others are more like a traditional bra. There are various back styles available too.

Fabrics often incorporate Lycra for a close, comfortable fit, but otherwise, we'd look for techical synthetic fabrics for best wicking and moisture management performance. Bear in mind that with extended use, the Lycra component of the fabric will lose its support and the bra should be replaced.

More Help and Advice

This article should have given you some basic pointers. The good news is that there's a load more advice on OUTDOORSmagic:

• Ask on the gear forum about general issues or specific items.
  
• Check the member reviews section for user experiences of kit.
  
• See OM editorial reviews on the front of the site for our impressions.
  
• Ask Richard Gear if you have a specific question you need answering.