And not from a training DVD either. Last night, my wife got a Wii. I've never seen one of those things before, so I tried the boxing game.
I don't know how many opponents I boxed before I finally lost, but it took about an hour, I could barely stand or breathe, and I was drenched in sweat. I had been doing well, but towards the end, my performance was definitely dropping. By the time my final opponent beat the crap out of me, I was relieved to get a break.
Today, my arms are still sore and feel like lead weights. Although upper body strength has never been my forte, I'm not a total weakling -- the first thing I do when I get up is 70 pushups, and I do other exercises as well.
Next time, I'm playing with an HRM attached.