By Bobby Maximus

I always celebrate my birthday by doing a savagely difficult workout.

As I age, I want to improve, not decline. That’s why, every year on my birthday, I wake up and immediately do one of my signature birthday workouts.

The workout is not just a test. It’s also a reminder that I’m becoming fitter with age, and that I still have the ability to improve no matter what year my birth certificate says I was born.

Birthday workouts have actually become something of a phenomenon in my community at Gym Jones, the gym where I’m the general manager. They’re a rite of passage that helps you enter your next year physically and mentally tougher, and jump start your body composition goals.

Because of how hard this particular workout is, a few of the over-age-35 people who train with me keep their birthdays secret. They don’t want to undergo the suffering.
Do this workout next time you turn a new year, or gift it to a friend. It’s hard enough that you’ll be glad you only have one birthday a year. And if you’re looking for more intense workouts that will make you unstoppably fit, there are 100 more like this one in my new Men’s Health book, Maximus Body.

Here’s how it works: Take your age. That’s how many reps of bodyweight squats and alternating lunges you’ll do. That’s 1 round.

What was your age again? That’s how many rounds you’ll do. So, for example, if you were turning 35 years old, you’d do 35 air squat and 35 lunges, 35 times. That’s 2,450 total reps.

Try to finish as quickly as you can—resting only as needed—while keeping good form throughout. Happy birthday!