During my 23 years with The Times’ sports department, I have held a wide variety of roles and titles. Tennis writer. Angels beat reporter. Olympics writer. Essayist. Sports media critic. NFL columnist. Recent keeper of the Morning Briefing flame.

Today I leave for a few weeks’ vacation, and when I return, I will come back in yet another incarnation.

As Christine.

I am a transsexual sportswriter. It has taken more than 40 years, a million tears and hundreds of hours of soul-wrenching therapy for me to work up the courage to type those words. I realize many readers and colleagues and friends will be shocked to read them.

That’s OK. I understand that I am not the only one in transition as I move from Mike to Christine. Everyone who knows me and my work will be transitioning as well. That will take time. And that’s all right. To borrow a piece of well-worn sports parlance, we will take it one day at a time.

Transsexualism is a complicated and widely misunderstood medical condition. It is a natural occurrence — unusual, no question, but natural.

Recent studies have shown that such physiological factors as genetics and hormonal fluctuations during pregnancy can significantly affect how our brains are “wired” at birth.

As extensive therapy and testing have confirmed, my brain was wired female.

A transgender friend provided the best and simplest explanation I have heard: We are born with this, we fight it as long as we can, and in the end it wins.

I gave it as good a fight as I possibly could. I went more than 40 hard rounds with it. Eventually, though, you realize you are only fighting yourself and your happiness and your mental health — a no-win situation any way you look at it.

When you reach the point when one gender causes heartache and unbearable discomfort, and the other brings more joy and fulfillment than you ever imagined possible, it shouldn’t take two tons of bricks to fall in order to know what to do.

It didn’t with me.

With me, all it took was 1.99 tons.

For more years than I care to count, I was scared to death over the prospect of writing a story such as this one. It was the most frightening of all the towering mountains of fear I somehow had to confront and struggle to scale.

How do you go about sharing your most important truth, one you spent a lifetime trying to keep deeply buried, to a world that has grown familiar and comfortable with your façade?

To a world whose knowledge of transsexuals usually begins and ends with Jerry Springer’s exploitation circus?

Painfully and reluctantly, I began the coming-out process a few months ago. To my everlasting amazement, friends and colleagues almost universally have been supportive and encouraging, often breaking the tension with good-natured doses of humor.

When I told my boss Randy Harvey, he leaned back in his chair, looked through his office window to scan the newsroom and mused, “Well, no one can ever say we don’t have diversity on this staff.”

When I told Robert, the soccer-loving lad from Wales who cuts my hair, why I wanted to start growing my hair out, he had to take a seat, blink hard a few times and ask, “Does this mean you don’t like football anymore, Mike?”

No, I had to assure him, I still love soccer. I will continue to watch it. I hope to continue to coach it.

My days of playing in men’s over-30 rec leagues, however, could be numbered.

When I told Eric, who has played sweeper behind my plodding stopper for more than a decade, he brightly suggested, “Well, you’re still good for co-ed!”

I broke the news to Tim by beginning, “Are you familiar with the movie ‘Transamerica’?” Tim nodded. “Well, welcome to my life,” I said.

Tim seemed more perplexed than most as I nervously launched into my story.

Finally, he had to explain, “I thought you said ‘Trainspotting.’ I thought you were going to tell me you’re a heroin addict.”

People have asked if transitioning will affect my writing. And if so, how?

All I can say at this point is that I am now happier, more focused and more energized when I sit behind a keyboard. The wicked writer’s block that used to reach up and torture me at some of the worst possible times imaginable has disappeared.

My therapist says this is what happens when a transsexual finally “integrates” and the ever-present white noise in the background dissipates.

That should come as good news to my editors: far fewer blown deadlines.

So now we all will take a short break between bylines. “Mike Penner” is out, “Christine Daniels” soon will be taking its place.

From here, it feels like a big improvement. I hope with time you will agree.

This could be the beginning of a beautiful relationship.