Today I took my Okinawan kobudo weapons outdoors and went to town. I know that's a bit of an oxymoron, but I'm just trying to make a point. There's just not too many schools that will structurally accommodate the swinging of a six foot bo. In my day I've come too close to breaking the overhead florescent bulbs (also six feet in length, ironically) wielding my weapon with reckless abandon. I like to feel free when I train.
Does your school ever conduct training outdoors? One summer day we took a class down to the beach for a two mile run followed by some basic drills done in the surf while drawing some spectators. Kicking in knee-high water provides a tough workout. Peter Urban, the legendary goju karate pioneer in the States, would occasionally have his uniform clad students run down the streets of New York outside his famous Chinatown dojo. I admit, Canal Street bears no semblance to a nature trail, but I'm sure a group of karate trainees jogging across busy Manhattan intersections was cheap advertising for Urban's school.
Most of the twentieth century founders favored rigorous outdoor training at some point. As a youth Gichin Funakoshi would practice kata during the midst of a raging typhoon to forge his spirit. Mas Oyama spent extended periods in the wilderness performing karate and Zen meditation under frigid waterfalls as part of his shugyo (austere training) regimen.
Fitness guru Jack LaLanne used to run these TV ads during the 70s for his health clubs with the promise of escaping the winter chill ("Baby it's cold outside!"). The classical dojo was not designed as a total haven from the elements - a departure from the insulated, air conditioned modern facilities. As historian Donn Draeger noted, the traditional training hall is "hot during summer, cold during winter; it has approximately the temperature of the environment beyond its walls." I really don't recommend training during extremely hot or cold conditions unless certain precautions are taken. Keeping yourself hydrated is a must during any strenuous activity, especially in the heat. Stretching and warming up the muscles and connective tissues is imperative prior to training, particularly when it's cold.
For me, martial arts training outdoors is ideal. There's nothing like it: fresh air, freedom, sunshine (when available) and if you live in the 'burbs like me you benefit from the surrounding oxygen-exuding plant life. Such is the symbiosis of living on our planet, for now, as long as we don't continue to ravage her natural resources.