Mix up your exercise routine to keep it interesting. This week, Trainer X tries the Schwinn Airdyne exercise bike.

I am a passionate guy; about my wife, about our kids, about mixed martial arts. And most of all, I am passionate about exercise. I mean, I love it!


I was thinking about it the other day; I am a professional athlete without a sport. Sure, I love running, jumping, throwing stuff, catching that same stuff and the like. But at 40, I'm not about to run out and join some senior wrestling league or row some zippy little boat down the river on Sunday mornings. I am your personal fitness coach, and it is my job to be in the best physical condition possible at all times.


So, in my quest for the perfect day of exercise, I take many different routes. Some days I run and lift in the morning and then ride my bike or run some more to meet my wife and jump in her car to go to our eldest's soccer practice. Some days I hit the bag and jump rope, while others I just head down to my basement (The Dungeon!) to see what happens. Today was one of those days.


It is no secret that I have recently been infatuated with the Schwinn Airdyne exercise bike (www.schwinnfitness.com); in fact, after they found out I'd picked mine up this weekend(, several friends text-messaged me to ask, "So, how is your bike?"


It is an old-school piece of equipment that has a gigantic fan for a wheel and the wind resistance is exponential, so the harder you pedal, the higher the resistance becomes. The arm handles move in conjunction with the pedals, so the workout is amazing and difficult at once. So, as I sipped my iced caffeine solution Sunday morning, my head was spinning with workout ideas - and now I pass them along to you.


Start out with a five minute spin on the bike, and when you're getting your blood flowing, make sure to pay attention to your RPMs (revolutions per minute), distance and time so that you can strive to improve in those marks moving forward during future intervals. After that, hop off and crank out as many pushups as you can (in good form, chest touching the ground each rep) and follow that with pullups. If you can't do a regulation pullup, rest your feet on a chair to help you out. Finish off with five minutes of running on a treadmill and take a sip of water before you repeat the entire cycle one more time.


Next, perform three abdominal exercises in a row, non-stop. I chose the ab wheel, bicycles and jackknives. They really take the Mickey out of me. Add in the same intervals running on the treadmill and perform the drills twice through, and you've got yourself two miles of running, three miles of biking and loads of calisthenics in a great workout.


Keep at it, gang - and make sure it gets harder, not easier, with time.


Darin St. George is a personal fitness coach at Gold's Gym in Natick, Mass. Visit his Web site at www.TrainerX.com.