Most people understand that to have stronger muscles you have to exercise, but did you know that you also have to count?  I've run into a few folks who lift weights or use some type of exercise machine until they feel tired.  Their argument is that as long as each time you exercise you feel tired, well, who cares how many repetitions you do?  What matters is that your muscles are tired.  Right?

Not quite.  Yes, exercising until you're tired is better than not exercising at all but why not get the most out of your time every time?  Why waste it?  Counting the number of repetitions is important for a few reasons and I'll cover one of them today: fatigue.

What is fatigue?  "The inability to continue functioning at a prescribed work rate in the presence of an increased perception of effort."  The key word in this definition is perception. Fatigue is not just a physical phenomenon resulting from insufficient energy.  It also occurs when you think you're tired or you feel tired or you feel disinterested.  It's your perception of the effort that determines the degree of fatigue.  Have you ever tried to exercise when you're in a foul mood or bored?  What normally is an invigorating thirty minutes on the elliptical or jogging trail turns into a dreary, drawn out, will-this-ever-end session.  You feel or you perceive that you're more fatigued than you actually are.  If, however, I start yelling at you, "Get your butt in gear! Come on! You got more than that!" (just imagine me doing that - it will bring a wide grin to your face), you will suddenly be much less fatigued.  Your perception has changed.  This is why counting repetitions (or having other objective measures like revolutions per minute) is so important to getting the most out of your exercise session (even if you work with someone who yells at you).  Keeping track of repetitions forces you to produce consistent levels of effort and yields the best results. 

For those of you who have been to Sports Center, you know all about fatigue.  We rate fatigue on a 0 to 10 scale where 0 is no fatigue and 10 is extreme.  When you're training your muscles, you want a fatigue level between 6 and 8 on a scale of 10 that occurs between 15 and 30 repetitions.  Training at this intensity will give you increased strength and endurance which most of us need in everyday activities (getting bigger muscles is a completely different training regimen).

If you exercise without keeping track of your repetitions and fatigue level, one day you might perform 20 repetitions and another day 10, or 30, or 6 because you quit when you feel tired instead of pushing yourself to reach at least the level of performance you achieved in a prior session. Inconsistent training yields inconsistent results.  Each session you should push yourself for one more repetition, at least.  Write it down along with your fatigue level.  Week by week, your repetitions will go up.  Then, one day, you'll discover that you can perform 30 repetitions of a drill with a fatigue level of 4.  This tells you that you're ready to increase the resistance or weight. When you do, your repetition level will drop closer to 15 or 20 repetitions.  That's okay.  You're in the right zone; the right combo of reps and resistance or weight.

So, who's counting?

Should we blame our back pain on the evolution of the human form? Do we have back pain because we were really designed to walk on all fours (or at least use all of our limbs like apes) and some tweak in the evolutionary cycle converted us to upright beings thereby squishing our discs? A doctor from Cedars Sinai Medical Center in Los Angeles, California seems to think so.

Dr. Aaron Filler, a spine specialist, has come to the conclusion that a shift in the structure of the spine, based on fossil evidence of a ape-like creature called Morotopithecus, allowed humans to walk and carry objects. This then created the perfect environment for back pain.

Great. So, now we can blame our aching backs on evolution. It's not our fault that we sit on our butts most of the day, lead exceptionally stressful lives, skip breakfast, rarely workout, and pop pain erasers as soon as we feel anything uncomfortable. Nah...it's the way we evolved. That's why we hurt.

Well, someone needs to let Nigerian and Filipino farmers know because they have four times less back pain than the citizens of wealthier countries. And the reason?  Well, most farmers are active, don't sit around, use their bones, muscles, discs, and work out their stress.

If you want your back to hurt less, move. You may need help figuring out how to move, how much to move, how often to move, but the answer for most back pain will not be found in the fossilized remains of a questionable evolutionary link. The answer is to move.

The decision goes against the advice of the American Medical Association and 85 other physician and health professional organizations.

First impressions make a difference in how well physicians and patients communicate, researchers said.

Supporters hope Michael Moore's latest movie will sway public opinion. The AMA and others counter that government-run health care isn't the right solution.