Environment Canada's weather guy — David Phillips — says last month was the warmest December on record for southern Ontario. The entire year was the second-warmest on record for all of Canada.

On Monday, Toronto recorded its warmest-ever start to a new year. That has those of us who prefer to exercise outside feeling pretty good. It's not often you can slip into a pair of shorts and go for a run in January.

Now, while it stayed fairly mild over the holiday season, there was one day where exercising outside was not an option — unless facing just-above freezing rain driven by strong easterly winds is your idea of a good workout. I may be fanatical when it comes to getting in my runs, but I'm not a lunatic.

Grudgingly, I made my way to a local fitness centre and a date with a treadmill.

I can do 16 kilometres on a treadmill, but I'd rather not. Besides the never-changing scenery, there are certain things about the act of running that really get your system moving — especially if you've been indulging in some of that rich holiday fare. When you're outside with a group of running buddies, you can deal with it. Drop off the pack for a few seconds and discreetly alter your personal atmosphere.

That doesn't work very well in a fitness centre — unless techno-rock music is thumping the sound system and every treadmill, elliptical, stair climber and stationary bike is occupied by someone burning calories at a furious pace. Noise and the smell of sweat won't be enough to mask your indiscretion. Back off the pace and you could fly off the end of the treadmill.

But now — as fitness clubs deal with a surge of New Year's resolution members — there's word of another risk to exercising indoors. An epidemic of community-associated methicillin-resistant Staphylococcus aureus, or CA-MRSA, according to the Canadian Medical Association Journal, is ready to invade locker rooms across the country.

CA-MRSA is a nasty bug that can cause large boil-like infections and hemorrhagic pneumonia or flesh-eating disease in rare cases. Last summer, it laid up Toronto Blue Jays outfielder Alex Rios for more than a month. The team took the unusual step of disinfecting their entire clubhouse and calling in the health department to try to trace the source of the bacteria.

The problem used to be limited to hospitals and certain high-risk groups, but it's becoming a threat where people gather to exercise as well, especially for people who play contact sports.

Steps they can take to reduce the risk include good hygiene, such as showering after every practice or game, cleaning common bathing areas frequently and regularly cleaning equipment.

A little caution should mean that your New Year's resolution to get fit indoors won't make you sick. Or you could run with a group and stay away from the person who drops off the pack for just a few seconds.