Ever have one of those days. Maybe you didn't sleep real well, or just had a stressful day at work. Whatever it is, you just don't feel like working out. Sure, you have a 3,000M swim workout on the schedule but man, hitting the couch and watching some tv sounds like a great option.
Then you remember reading somewhere about overtraining. Not so sure exactly what the advice was, but "everyone" knows overtraining is bad. So you head straight home, convinced that you are in a state of overtraining and need "rest" to avoid digging a deeper hole.
But is this the right thing to do? Maybe. Maybe not. If you are deep into a training cycle, pushing your personal limits, it is a real possibility you may have pushed beyond your recovery capabilities. A few days of active recovery or even straight up rest could be the right course of action. A seasoned endurance athlete will know exactly what this feels like. It is different than your normal heavy legs or dragging at the end of the day. And true overtraining and adrenal fatigue are a completely different beast that can happen. You can read more about that here.
When you are having THAT day, go and start the workout. Using the 3k swim workout as an example, get to the pool, stretch out, and get in the water. If you're anything like me, not so hard getting in the water, a challenge to actually get your head under water and push off for the first length.
Suck. It. Up.
After warming up, give yourself a minute and start your main set, whatever it may be. One of two things will happen - you will either start the main set, hit your expected times and start to feel better, or you won't. After a few reps in the main set - about 20 minutes into the workout - you will know where you're at, and you will know what to do.
Still feel like crap, not performing well? Get out of the pool, shower up, call it a day.
Hit your times? Continue on. Finish the workout as planned.
I've been here more than I care to admit with all three sports. Of those, I can count on one hand the number of times I called it a day. Every other workout, once I got moving I started to feel better, sometimes even great, and was able to get the scheduled work done.
Properly training for your "A" race is a process that takes months of hard work. Over that time you won't always feel great, and you won't always have that gung-ho attitude every time you swim, bike or run. Give it a go for 20 minutes and see what happens.
Train hard. Stay focused.
You can find the first three rules here, here, and here.