Outdoors training is one of my favourite things, and I do my daily practice out in the open troughout the year. Indoors, you need to clear the space, accommodate others, ventilate before and after...whereas outside there's as much room and fresh air as you need. Of course, during the summertime everything is just peachy, but wintertime training may seem like a big challenge for many.
Actually, even in a country as cold as Finland, it really isn't as big a deal as one might think. So, here are some simple tips I've found useful for outdoor training during the colder seasons!
Rather a bit too warm, than a bit too cold
In arts like chi kung, kungfu and zen, where relaxation is crucial, practicing while freezing really doesn't do you any favors. Cold makes the body tense up; shoulders go up, breathing gets shallower, and the body generally just wants to move about to fight the conditions. This is not a good recipe for meditation or stance training, where you should remain static yet relaxed for long periods of time. A good rule of thumb is to be slightly too warm during practice. Make a point to wear clothes generously, and then start removing items if you get too hot.
Keep things loose
Probably the most common problem with any practice clothes - indoor or outdoor - is for them to be too constricting or restricting of movement. It's easy to go wrong here, especially when choosing outdoor training gear. First of all, make sure that you can do any movement with ease while wearing your full set of clothes. Secondly, your clothes shouldn't coax your body into wrong positions and bad habits. This can happen quite easily yet insidiously, and in the long run may cause issues where the actual prpblem may be hard to pinpoint. A tight-fitting scarf can cause shoulder stiffness and neck pain; a body suit with a snug waistline may cause stomach problems or shallowness of breathing; shoes that cradle the ankles too closely can spell trouble for your entire posture. For the outdoors, a good, loose-fitting coverall usually has all the important bases covered for outdoor practice.
In arts like chi kung, kungfu and zen, where relaxation is crucial, practicing while freezing really doesn't do you any favors.
Coveralls are great!
The problem with combining lots of different pieces like pants and jackets for your Winter training gear is that there are more openings, so it's easier for the cold to seep in. Also, outdoor pants may often prove to be constricting around the waistline. And, when your training gets lively, suspenders tend to fly off, buttons and zippers pop open, and so forth. Coveralls and outdoor full suits work great with training, because they allow for maximimum mobility, while at the same efficiently preserving body heat. For years now I've used coveralls meant for ice fishing and other Winter outdoor activities, and they've never got in my way.
Stay light on the hands and feet
Often I see people training kungfu in relatively heavy training shoes, which I personally never recommend. A common feature with many sports shoes is that they lift up the heel and bring slightly more weight to the toes. Especially in kungfu, I find that this messes with your posture. It might feel easy and nice to train with bit of air under your heels, but this often curves the back in stances, and may also be detrimental to your knees. I favor light shoes with thin, even soles - even when practicing outdoors. Yes, heavy winter shoes may be nice and warm, but they're too unwieldy for most kungfu leg techniques. Same thing with gloves; it's better to use light and well fitting fabric gloves, than heavy mittens only capable of forming a bad fist. Kungfu techniques can use any part of the hand, so you should keep your options available. And don't worry about getting cold - when you make sure that your torso, arms and legs are well warmed, hands and feet usually don't mind a bit of chill.
Wear layers
Up where I live, Winter lasts a long time, with temperatures ranging from about 5°C (40°F) to -30°C (-20°F). For almost 20 years now, I've done (and loved) my daily training outside through all this. To benefit from the same outdoor clothes through the entire wintertime, create a set that has layers you can easily add or take away. I have my coveralls, a good single body layer, plus a warm long-sleeved set of underwear. Add to that a knit cap, a loose cotton neck protector, two layers of socks, and optional two layers of light gloves, and I'm ready to take on pretty much any Winter day. Just adjust the set as needed, and you can find a combination from the same clothes for any temperature.
Although that was a lot of gear-related advice, generally speaking kungfu training doesn't require much in the way of accessories. Of course, as with anything, you can go crazy with gear, but I think exercise shouldn't about the equipment. No need to supplement your kungfu with gyms or practice halls, special floors or yoga mats, treadmills or hand weights; just get some empty space and you're good to go!