I found this very good article out on racquetnetwork.com and thought you might enjoy it.
I seldom see articles there about pickleball - but found this one to be very intereting. Click on the title below to read the entire article.
Singles Pickleball Burns Calories
Written by Brent Johner
on December 1, 2009 – 1:59 pm
When two athletic players face each other on a pickleball court, they both get a good cardio workout. Like squash, pickleball played at a high level requires a lot of lunging, a lot of volleying and a lot of fancy footwork. Therefore it is not uncommon to see player heart rates rise into the 150 to 175 range.
.............The quality of the workout depends a great deal on the ability of the players to keep the rallies going, of course. But two skilled players can easily sustain rallies of 15 to 20 strokes each or more.....