Muscling into Fitness - an Exercise in Rhyme

My doctor says to exercise;
I look in the mirror with gawking eyes.
Once I had biceps and iron thighs,
But now I can only rationalize.

I'm so out of shape that I think I would hurt,
And I can't seem to find a single clean shirt.
Besides, I wouldn't want to overexert.
Frankly, I'd much rather eat my dessert.

Guilt doesn't work, and it's not just the cash.
I'd like to go back to the gym in a flash,
But I'm afraid I'd develop a rash
Or lift and grunt into whiplash.

Workouts simply take too darn long,
Waiting in line for machines, to get strong
With guys that are built like old King Kong.
It's just a place I don't belong.

My sneakers are old, and they give me a blister.
Besides, I'm still not as fat as my sister.
I think I might need a breathing assister,
Or maybe a no-membership black-lister.

The guys might ogle my leotard,
As I struggle to make my flabby form hard.
And my body's rather battle-scarred
From years of fitness disregard.

OK, so I'll get up and go to the gym,
'Cause it's true about fitness, "You sink or you swim."