Overtraining?

Hey Mark,

You're already doing something right here.  You are paying attention to the fact that your body feels different and you are trying to figure out why and how to fix it.   Like Max says, your back injury may be part of the problem.  Iinjuries take time to heal.  Moreover, the rest of the body became deconditioned while you were recuperating.   You need time to adapt to an exercise regimen again.   Full-blown overtraining where the body is cannibalizing itself is probably not what you have.   Fatigue from not fully recovering from a couple of really hard workouts seems plausible.  It sounds like you bumped the intensity and the distance in the last few workouts.   The usual advice here is to take a day off until your body feels pretty normal, then resume at a lower intensity to make sure that swimming feels good again.  You say you are already doing this.  Give it some time.  You might want to check your temperature.  You could have picked up a bug (mononucleosis is the disease you want to be aware of here).

Some other things to watch out for. 

1)  Aggravating the back injury.  You know where that hurts.  Back injuries are nothing to fool around with.  Get good medical advice if your back hurts or you feel some tingling or numbness in the extremities. 

2)  Working out too hard too often.  You need a hard workout once or twice a week and it will result in some general achiness.  When done just right, it is a good achiness.  It feels more like a warmth or glow that actually feels good.   If you do too much, you are going to feel so sore so that it affects your sleep and makes you look funny when you walk (more a problem for runners actually.)  You need to make up for the hard days with some easy days to give the body time to adapt to the increased stress.

Many people report that the morning heart rate is the thing that they can monitor to detect oncoming fatigue.  For me, that is not effective.  I find that other things affect the morning heart rate (like knowing a stressful presentation is coming up) more than the fatigue effect.  I use a little stress test. I run up one flight of stairs to my office every day.  On a normal day, the heart rate rises so little I hardly notice. If  I am due for a rest day, I can feel my heart pound for a minute at the top of the stairs.  I know how if feels from experience not from any particular BPM.

Keep your swimming going.  You'll be glad you worked through this.

TW