Miami ? As Erik Spoelstra found out this season, everything’s different once becoming a head coach. The pay is better. The pressure is higher.

The digestive system tends to change, too.

“I used to fire down about three or four hot dogs right before the game, slam a coffee and head out there,” Spoelstra said.

Now? He can barely eat anything on game days.

Such is life for an NBA head coach, the role Spoelstra slid into this season with the Heat.

He led Miami to a 28-game improvement this season, going from a league-worst 15-67 last year to 43-39 and the No. 5 seed in the Eastern Conference playoffs. Not bad for a guy who acknowledges that nervous energy consumes him in the hours before tip-off, yet seems poised and confident heading into the rigors of a postseason in this position for the first time.

“It just feels second nature,” Spoelstra said. “It’s not anything new. I’m sure it’ll be much, much different going out there and actually coaching, but the playoff prep — getting the video, the staff, keys, all of that together — I feel very comfortable in that role.”

With good reason.

He had a couple of pretty good teachers along the way.

When Spoelstra came to the Heat, his arrival coincided with the beginning of the Pat Riley era in Miami. And in time, Spoelstra and Stan Van Gundy — the former Heat assistant under Riley, then head coach after Riley’s first retirement — became close friends as well, guys who would spend hours picking each other’s brain about the game.

As he approaches Game 1 of Miami’s first-round series in Atlanta on Sunday, Spoelstra is remembering the lessons of each.

“I learned quite a bit from Pat, just in terms of the dedication and the work ethic and turning over every stone and making sure you’re fully prepared going into a series so there aren’t any surprises,” Spoelstra said. “The same goes for Stan Van Gundy. Doing those playoff preps for the two of them, I don’t think it can prepare any staff better than what we are right now.”

That’s not to say he’s merely a clone of Van Gundy and Riley, both of whom won 42 games in their first season with the Heat.

Not even close.

Heat players insist Spoelstra has become his own man — a coach shaped in large part by the tendencies of those who preceded him, sure, but a Tupac Shakur-listening guy who went out and earned the respect of those in the Miami locker room even before the season began.

“Honestly, he had it from Day 1,” said Heat guard Dwyane Wade, this season’s NBA scoring champion. “I thought he did a great job last summer of meeting with everybody, flying to the cities where people were, meeting with them in Miami, talking to guys face-to-face as a man and telling them what he expects. I thought that was very big. So when training camp began, his voice was heard.”

It was not always perfect ride.

Spoelstra had a young team that made mistakes, and in the same vein, the rookie coach didn’t always grade himself so highly, either. When Miami lost by two points in Dallas earlier this month, a game where rookie point guard Mario Chalmers was called for an offensive foul with 2.3 seconds left, Spoelstra didn’t blame the kid.

He blamed himself for not calling time-out.

“He does a great job,” Heat forward Udonis Haslem said. “He can speak the lingo with guys. He can communicate on their level, but from a coach’s point of view. He’s a lot more vocal now, but I don’t see a whole lot of other changes in him just because he’s the head coach now. He still breaks down his own film. I don’t know if many head coaches do that.”

Jermaine O’Neal has only seen Spoelstra work for two months. It didn’t take long for him to become impressed, either.

“He’s a players’ coach,” O’Neal said. “If you had a veteran team, he’d probably go a different route. But this is a younger team. And form what I’ve seen, what I’ve heard, he’s done a pretty good job handling the transition. Sometimes it’s hard for a coach to find that fine line with being aggressive and being a players’ coach.”