Don't.

The ache in the knees should have been a warning sign.

One look at the training logs told me the terrain of the previous weekend could have been the root cause of discomfort.  Sure, others outside the Gulf Coast can scoff at the 50-to-100-foot variations in total elevation, but most physical therapists would probably not recommend my county-fair-style wanna-be roller coaster courses from Sunday morning or Sunday afternoon.

Not the best training surface for a pair of recovering achilles tendons.

Since the achilles were not aching, the next suspect would have been the shoes.  Nope.  I ran in shoes which had 300 and 180 miles, respectively.  Old shoes cause aches first in the ankles, then the knees, closely followed by the hips and low back.

I've waited until the "back pain" stage to buy the next pair.  It's amazing how quickly the ache goes away.

As I lay, stewing in my own 101.3-degree juices, it suddenly came to me.

Eric.  And 13,000 of my closest (some as stone cold sober as me!) friends.

I had a sneaking suspicion something was not going to go well when he asked me: 'Mike, do you have any recommendations on how to run when you cannot breathe?'

My one-word answer: 'Don't.'

Most experienced runners know the "chin rule" when it comes to running while sick.  If the congestion or discomfort of an allergy or cold is limited to the head and sinuses, runs at a decreased intensity are acceptable.  If the congestion is below the level of the chin (the small accessory muscles of the ribcage is a good sign - if the ribs are tender the accessory muscles have probably been used too much), rest, rest and some more rest is a great idea.

The weekend's exposure more than compensated for the wisdom and prudence I used through the end-of-year holidays.  Sometimes the runner can exercise caution - avoid crowds, eat properly, and train smartly - and still one (or two, or three, in my case) exposures can put them down for the count.  Illness can be punishing enough without adding to it, so don't.