There are 2 hard and fast "unofficial" rules of triathlon training:
Rule #1: Don't get injured.
Rule #2: Don't get sick.
If you can obey those 2 rules you will be much more likely to stick to your training plan. Injuries can derail your entire season (that's why it's #1) while sickness can make you inconsistent or train less. Both can chip away at your enthusiasm which is critical in any endurance event.
Living in a house with kids makes rule #2 very hard to follow. My kids, over achievers that they are, dutifully bring home every microbe and germ possible. It's easy to see who is responsible for the infection by watching who gets sick first. They usually get a lecture from mom/dad about hand washing, covering coughs, blowing noses, etc.
The latest round of illness was a nasty little stomach virus (most likely a norovirus) came home last weekend thanks to boy #2 (my second oldest). I picked it up last Thursday morning and have been suffering since. The symptoms are beginning to wane but are quite uncomfortable and don't allow for any training. Period. Unless I want to puke my guts out every few feet and pass out. Thankfully this type of virus goes away within 24-48 hours so I'm hoping to be back in the saddle by Monday.
For now it's a liquid diet of apple juice and water. Tomorrow will be toast and crackers and hopefully protein of some sort.