Charles Barkley once quipped, when asked about playing a back-to-back-to-back in the NBA, that he couldn’t have sex three nights in a row, much less muddle through a string of professional basketball games. Sir Charles, then, is surely sympathetic to the plight of the Miami Heat.

LeBron James and company are now in season four of an especially demanding back-to-back-to-back-to—possibly—back, and it’s clear that the team is worse for the wear.

The Heat have appeared in three consecutive NBA Finals, and look, even with the Indiana Pacers looming, at worst they're an even bet to return for a fourth. This is a lot of extra basketball they’ve played, and there’s more to come.

Since the Big Three united their considerable powers in July of 2010, the Heat have played 67 playoff games. This nearly full season of extra basketball comes in addition to the regular-season grind and LeBron James’ 2012 Olympic experience.

"We've played a lot of basketball in our four years together," an already weary James told CBS's Ken Berger in January. "It's taken a lot of wear and tear on all our bodies. It's mentally fatiguing. And you just try to find the motivation the best way you can as an individual and as a collective group."

It's unsurprising that this has taken a toll. In basketball, in the words of the American Academy of Podiatric Sports Medicine, “tremendous pressure is exerted on the foot and ankle.”

The floor is hard and unyielding, and the cuts required by the NBA are sharp and frequent. Chronic injuries are not so much common as part and parcel of playing the sport—an occupational hazard. It’s really hard to play as much high-level hoops as the Heat have in the last 41 months.

This is especially true when the system in question—specifically on the defensive end—is a hyper-frenetic, attacking one.

This truth is further supported when the team in question is the oldest in the NBA, which the Heat, with an average age of 30.7 years, are, as outlined by Reuben Fischer-Baum for Regressing/Deadspin.

Miami is, understandably, a tired bunch. Evidence of this fatigue is present in nearly every aspect of the team’s performance.

A defense that finished no lower than seventh in efficiency during each of the Big Three’s first three seasons together has, thus far in 2013-14, slipped out of the top 10, according to ESPN.

Even the Heat’s pace of play, relative to the rest of the NBA, is slowing a bit. In 2011-12, the season that culminated in LeBron James' first title, Miami played at the 14th-fastest clip in the Association. In 2012-13, the Heat slipped to 23rd. So far this season, they’re ranked 26.

Granted, in these three seasons, the Heat used 93.7, 93 and 93.7 possessions per game. The story here is more about the rest of the league speeding up, though it’s noteworthy that Miami hasn’t, ahem, kept up the pace.

The problem becomes more marked on the level of the individual players. The Heat’s (small and possibly temporary) step backward in 2013-14 isn’t a function of one or two players being off their games. The thing is systemic.

Each of Miami’s top contributors in 2012-13—a group that includes James, Wade, Bosh, Ray Allen, Mario Chalmers, Shane Battier and Udonis Haslem—have seen their win shares per 48 minutes dip so far this season, per Basketball-Reference.com.

Among players who were members of the rotation in both seasons, only Norris Cole, Chris Andersen and Rashard Lewis have seen their per-minute production increase—and each case was a marginal improvement.

Now, exhaustion isn’t necessarily a death knell for a contender. This is the "Dynasty Problem." In order to keep the party going—to compete for championships across multiple seasons—an organization has to fight through not only entitlement and boredom but also sheer fatigue. That’s the bad news.

The good news is, it can be done.

In the excellent book Showtime: Magic, Kareem, Riley and the Los Angeles Lakers Dynasty of the 1980s, Jeff Pearlman detailed how Pat Riley—as a head coach and assistant—steered the Lakers to nine NBA Finals appearances in 12 seasons. It wasn’t easy. There were ups—plenty of them—and downs, nearly as many.

One season of particular interest was 1988-89. The Lakers were going for a rare three-peat—so rare that their opportunistic coach trademarked the term—but they looked off their game in the regular season.

While they won 57 games, it was the first time since 1983-84 that the team failed to crack 60. There were other worrisome signs, too. Despite another dominant season from Magic Johnson—he won his second MVP in three tries—the Lakers looked old, disinterested, distracted and past their prime.

Riley didn’t panic in the regular season. Just get to the playoffs was the motto. And, once they got there, the approach looked wise—at first, at least.

Los Angeles blitzed the Portland Trail Blazers 3-0 in the first round. The Lakers rolled the Seattle SuperSonics 4-0 in the semis. Then, in the Western Conference Finals, they swept the rising Phoenix Suns to set up a finals rematch with the Detroit Pistons.

And then Pat Riley did something really stupid. Rather than let his old, tired and experienced squad rest and regroup in the week-plus between the conclusion of the Western Conference playoffs and the start of the NBA Finals, the cocksure coach put his team through a grueling series of practices. He explained to his staff that he didn’t want to take his foot off the gas until the three-peat had been sealed.

It was a decision he’d come to regret. The Pistons swept the Lakers 4-0, and "Showtime" never won another title. Many in the organization blamed Riley’s bizarre, and bizarrely timed, boot camp for the collapse.

There’s a lesson in this for Erik Spoelstra—and with Riley still serving as Heat President, it’s one that likely won’t be overlooked: take it easy.

It’s OK, and normal, for a veteran team to be tired. The games that matter aren’t being played now. The most important thing to do is rest up and stay healthy—Riley lost Byron Scott to a hamstring injury during one particularly intense post-WCF practice session—and stay unwaveringly focused on the  ultimate goal.

The Heat, to their credit, have done this. The Big Three have played fewer minutes per game, in total, in 2013-14 than they did during 2012-13 and fewer during 2012-13 than they did in 2011-12.

Each of James, Dwyane Wade and Chris Bosh have played fewer MPG so far this season than they did last season. Miami has also, over the course of the year, been noticeably less active on defense than it has in previous campaigns.

Another antidote to concerns about Miami’s tired roster is the nature of the playoffs themselves. While the regular season is a bear to get through—the travel, the tightly packed games—the playoffs are a relative cakewalk. Bye, bye back-to-backs.

The Heat are old, and the Heat are tired, but if Miami doesn’t win a third championship in as many seasons this June, that probably won’t be why. It’ll be because they just aren’t good enough.