Yoga isn’t as easy for me as it used to be.

Yes, it’s always been challenging and yes, I’d wake up with achy hamstrings or butt-cheeks, but this is ridiculous.

The other day in class I realized the extreme shoulder pain I’d experienced for several months before Christmas (the injury that drove me to a physical therapist and that, with her help, subsided) was back. I talked to my teacher about it and she suggested I stop doing down dog and chaturanga.

I balked. Or maybe it was more like scoffing. Or laughing in her face.

“Can you even do yoga without them?” I asked like a brat.

She laughed right back in my face.

“People do yoga without arms! You can do whatever you have to do.”

Fine. I know that she’s right, but personally I can’t imagine yoga without those core, strengthening poses that make my yoga feel like a workout.

Many teachers make those poses optional. They let students choose between down dog and child’s pose or between knee-chest-chin then cobra (or some other gentler sequence) and chaturanga then up-dog.

But I always choose them. I want them. I crave them. And so I’ve kept doing them since that conversation with my teacher, who was only looking out for my best interests.

And today I paid the price. After an early series of core exercises, I suddenly felt a sharp pain in my neck and, by the end of class, my shoulder hurt so much I couldn’t even lie in savasana without pain.

It’s my fault. I should have listened.

I ran into a massage therapist who’s worked on me a few times the other day and told her about my predicament. She suggested I take a week off yoga. I reminded her of my Yoga Challenge. She was quiet for a moment and then said maybe my challenge has always been to really push myself hard in yoga, but maybe now my challenge should be learning to enjoy my practice and benefit from my practice without those poses that have always seemed so essential to me. “It’s a different kind of challenge,” she said.

(She also said maybe the yoga wasn’t to blame. When I told her my injuries healed over my month-long vacation in L.A. and I thought less stress and less lugging of my laptop could have contributed to their improvement, she said, “It could also be the weather.”)

In class today, while I was rubbing my poor aching neck, the teacher said down dog and chaturanga are amazing, strengthening poses when done right, but they really beat up your neck and shoulders when done wrong.

I felt like he was talking directly to me.

But I also wondered how I managed to do so much yoga for so many years and never have a problem.

Is it because I practice less consistently than I used to?

Or is it because I’m getting old?

Are my 40-something-year-old muscles and tendons simply less supple and more susceptible to injury than they were when I was 20 and 30-something years old? Goddamn it, these same body parts used to down-dog and chaturanga and handstand and wheel pose for hours on end to the great, eclectic tunes of teachers who kicked my ass much harder than anyone I’ve found here in Boston! And only occasionally did I have to lay off shoulder stand to let a neck tweak heal.

A woman I talked to in the steam room after class told me about Terry Gross’ Fresh Air interview with journalist William Broad about the benefits and risks of yoga. She said Broad admitted to pushing himself too hard when he was trying to impress a pretty girl in his yoga class. I figured my clinging to the yoga poses I did so easily when I was younger was equally ego-driven and foolish.

Maybe my yoga teacher and massage therapist are right: It’s time to consider a kinder, gentler form of yoga, one that babies my achy muscles and aging joints.

After class I went home, took two Advil, dug up an ancient tube of Traumeel (expiration date 2009), slathered it all over my neck and shoulder and considered modifying my practice tomorrow.

While this strikes me as sad, it’s really just another reminder that in life we must always be willing to adjust our behavior and expectations. Life is always throwing a curve ball at us and saying, “Heads up!” And it’s up to us to look upwards, plant our feet firmly, position our hands—and do our best to catch it.