You might think summer is a time for rest and repose for the NHL player, a time for him to reflect on the past season and the litany of successes, failures and lessons learned. You'd be wrong.

You might think that, after toiling through an 82-game regular season, enduring a physically taxing, travel-packed schedule, guys spend their offseason in exotic locales, sunning themselves and swilling margaritas.

There might be time for such quick jaunts, sure, but odds are that the majority of their days and weeks are spent in the gym, hunkering down with much more punishing activities, activities that involve things such as sled pushes, sprints and supplements.

Some NHLers have their own thing they like to incorporate into their offseason routines. Rangers goaltender Henrik Lundqvist likes to play tennis with legend John McEnroe ("He's still fast. And he's not giving me any freebies," Lundqvist said of McEnroe). Patrick Kane plays pickup hockey in Buffalo in a few men's leagues ("Some [of the leagues] are better than others," he explained). Many players seek skills specialists, with a name like Darryl Belfry becoming more and more popular in the field. (New Jersey Devils forward Travis Zajac worked with Belfry all summer for the first time and is eager to see the results: "We'll see how it works.")

Regardless, the NHL athlete has evolved, and so has the training regimen required to remain at peak physical condition when the next season begins. Rather than "play their way back into shape" when training camp begins, players want to be at optimal performance levels as soon as they hit the ice.

Hence, the devoted pockets to some of the biggest names in hockey training: Gary Roberts, Andy O'Brien, Matt Nichol and Ben Prentiss, to name a few.

Whether it's the location, the clientele or the methodology that attracts a player to his trainer, the allegiance is strong. Whatever competitive advantage a player can gain -- lowering his body fat, increasing his foot speed, improving agility -- these trainers are entrusted to provide results. It's a big business, and business is booming.

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It wasn't always this way, of course. Trainers Peter Twist in Vancouver and Lorne Goldenberg in Ottawa helped revolutionize the idea of strength and conditioning coaching in Canada, boasting high-profile clients and innovative approaches.

"You can definitely feel it when you have the puck and guys are trying to get it but you're fighting them off," Steven Stamkos told NHL.com in 2012 of the benefits of his workouts. Getty Images

This got the ball rolling by exposing players to the advantages of fitness.

The NHL's rule changes in 2005 -- implementing a zero-tolerance policy on interference, hooking, holding and obstruction, which ended the old clutch-and-grab portion of the game -- also had a significant impact. Whereas bulk and brawn used to reign supreme, the new game has produced a wider variety of success for players of different stature.

"You're seeing a more dynamic athlete emerge," said O' Brien, who trains the likes of Sidney Crosby, Nathan MacKinnon, John Tavares and Jason Spezza.

Speed, mobility, agility, even adaptability are at a premium, a marked contrast from the days when behemoths such as Eric Lindros were patrolling the ice.

Naturally, that has changed how players train. Rather than focusing solely on putting on weight, adding muscle and bulking up, players want to be lighter, faster, stronger, but also efficient in their movement.

"One of my clients, before the rule change, was 250-260 [pounds]," said Toronto-based Nichol. "After the rule change, he was 220-230. Before, he was training as an offensive lineman. Now, he's training like a defensive back."

Hockey is unique in the fact that, like football, it is a collision sport that requires speed and power. But, like basketball, it carries some of the toughest aerobic demands. Factor in what many consider to be the most grueling schedule around, with little time for recovery, and it presents a myriad of challenges.

"You can't afford to be carrying around any nonfunctional weight," Nichol said.

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Although there is significant overlap among many of the big-name trainers, each one has his own calling card, his own philosophy.

Roberts has one of the most impressive lists of clientele and facilities, plus he appeals to players because he played the game. The 48-year-old won a Stanley Cup with the Calgary Flames in 1989, so he can relate to players on a level other trainers cannot.

Nichol, who counts Roberts as a friend as well as a former client, calls him a "pioneer" in the field and said Roberts understands things that cannot be learned from any level of studying or training.

Nichol chuckled and drew the comparison of Ivan Drago and Rocky Balboa in "Rocky IV" when describing Roberts' outfit to his own.

"We're a lot more bare-bones, blue-collar," Nichol told ESPN.com. "I was a competitive weightlifter. A lot of my methods are old-school. We're pretty basic here."

One Day In The Gym Want to know what a typical day of offseason training looks like for an NHL player? Top trainer Ben Prentiss gives ESPN.com an inside peek at a sample workout regimen from Prentiss Hockey Performance. A. Hip mobility, self myofascial stretching

B. Penta jumps over hurdles, 5 sets 2 reps 90 seconds rest

C. Power snatch off blocks, 5 sets 3 reps 100 seconds rest

D. Lateral sled running, 4 sets 20 yards 75 seconds rest

E. Kettle bell swing-throughs, 3 sets 10-12 reps 60 seconds rest

F. Ankle mobility/neck

Meanwhile, O'Brien employs an approach that feels a bit more scientific, tailoring each program to the individual by assessing movement efficiency and muscle imbalances and by incorporating extensive video work.

O'Brien, who also brings up "Rocky IV" and said he was mesmerized as a youngster by the way the Russians could actually calculate performance in the iconic movie, studies skating and playmaking intently and uses that as a guiding force to instruct his approach.

With the different planes of motions at play in hockey, O'Brien tries to home in on specific movements and actions that have a direct translation onto the ice. Take the crossover in hockey, a move essential to most every player's performance. O'Brien tries to increase force production in his workouts to aid in that movement, hoping to improve acceleration.

O'Brien also has his group make an annual trip to Vail, Colorado, at the end of every summer for altitude training. Although he said the experts are split on how beneficial the physical effects are, O'Brien likes knowing his players are exerting themselves to maximum degrees -- a mental task as much as a physical one.

Some team togetherness and bonding in an isolated location free from coaches, fans and media doesn't hurt, either.

"It was a good week out there," Tavares told ESPN.com of his week in Vail this summer. "It always gets me ready for the season."

Meanwhile, Connecticut-based Prentiss prides himself on a legion of motivated players to whom his devotion is a constant.

Understanding that the needs and schedules of every player are different, Prentiss is as accommodating as possible in helping guys train at their convenience, without sacrificing personal attention.

He'll be in the gym on the Fourth of July, Memorial Day, you name it. Max Pacioretty wants to be in the gym working out at noon the day after his wedding? No problem, Prentiss said.

Prentiss understands that each player deals with different demands off the ice, part of why his flexibility is so important. Veteran New York Rangers forward Martin St. Louis might be getting up at the crack of dawn to take his kids to hockey, and Los Angeles Kings goaltender Jonathan Quick might have been up late with his young son. St. Louis Blues defenseman Kevin Shattenkirk had 13 weddings to attend this summer, making weekends difficult.

"My availability to somebody 24 hours a day, whether it's training, nutrition or recuperation, I think that's one of the points," Prentiss said of why guys come to him. "Everybody's different. Everyone has different philosophies."

Everyone has different workouts, different moves, ones players both like and despise, depending whom you ask.

Prentiss said Quick hates the Kaiser runner, St. Louis dreads anything outside (modified strongmans, sled walks, etc). Pretty much everyone in the O'Brien camp dreads what are called "finishers," an anaerobic threshold task at the end of the workout, one that alternates between lactic-driven and neurally driven exercises. Nichol knows his guys are practically ready to drop by the time they leave the gym, no matter which combinations of exercise they found on the board when they entered the gym.

Former NHL player Gary Roberts has been training players at his fitness institute since 2011. Twitter/@GaryRobertsHPT

"It's kind of an all-continuous burn through my body, I guess you'd say," Seguin told ESPN.com of the post-Nichol workout sensation.

The question remains: How much is advantageous? And when does it become counterproductive?

According to Dr. Vonda Wright, a top orthopedic surgeon with years of experience treating elite athletes, it's about balance. Finding the time to rest and refresh is vital for any player before getting back in the gym.

"You come off, hopefully, a Stanley Cup championship, and you're just a wreck. Eighty-two [regular-season] games a year, who are we kidding?" asked Wright, who knows all about the rigors of the NHL (she's married to former Pittsburgh Penguins defenseman and two-time Stanley Cup champion Peter Taglianetti).

"Whether you're a 17-year-old kid from northern Canada, approaching his prime, or you're Mark Recchi, with [22] seasons [of experience], everybody needs a rest period. We really encourage athletes to have a physical rest and mental rest. You need to turn off for a while."

Wright, who will also serve as the medical director of the UPMC Lemieux Sports Complex in Pittsburgh when it opens next summer, knows well about the demands on an NHL player's body, especially with the emphasis on core muscles, lower-body strength and lateral stability ("strong butts but tight hips," she joked, a veteran of conducting many hip arthroscopies).

She suggests that a total body functional assessment to see "what's strong, what's weak, what's tight, what's loose," is best for players when beginning their offseason training. Correcting imbalances or overuses is common practice.

"We take a really functional approach to what the deficit is and build programs from there," she explained.

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One of the commonalities among these trainers is the importance of nutrition.

For most, it's not an optional part of their training regimen but a mandatory one.

Some guys might have to curtail a sweet tooth; some guys might need a food-allergy-specific diet (Prentiss helped Chicago Blackhawks veteran Brad Richards and his fiancée, who has celiac disease, with a gluten-free diet); and some might even have trouble putting weight on.

How To Fuel Your Body A sample diet from Prentiss Hockey Performance:



Meal #1



Start with glass of water with lemon or lime



2 pasture-raised eggs



4 oz. bison burger



1/2 avocado w/Himalayan salt



1/2 cup organic mixed berries



Meal #2



(pre-workout)



Essential Amino Acids mixed with water



Meal #3



(post-workout)



50 g protein (grass-fed whey or non-soy plant-based)



8 oz. tart cherry juice



Meal #4



8 oz. grilled chicken



Large organic salad, mixed greens and vegetables



Olive oil-based dressing



Meal #5



3 dried figs



Unsweetened shredded coconut flakes



1/3 cup sprouted nuts



Meal #6



8 oz. wild salmon



Steamed or roasted vegetables



Sweet potato

"I honestly can eat McDonald's every day and I'd lose weight," Philadelphia Flyers winger Wayne Simmonds confessed to ESPN.com last month.

Of course, that's not an option for Nichol's clients.

In fact, Nichol actually brings an extra level of expertise in that department. Before his current gig, Nichol worked as the strength and conditioning coach and the team nutritionist for the Toronto Maple Leafs from 2002 to '09.

Responsible for dispensing "lotions, potions and pills," Nichol soon realized he was assuming massive liability for the players he treated without full information about what some of those supplements entailed.

When the league adopted a new drug-testing policy in 2005, Nichol wanted to do his due diligence about all of these products. He contacted each company he worked with to see if it could provide documentation about all the ingredients it products contain, as well as an assurance that they did not contain any banned substances. The companies couldn't do that, so Nichol decided to create his own supplement. Procuring the raw materials himself and having it undergo third-party testing, Nichol finally had a product he was confident was safe and effective.

That was the genesis of Nichol's BioSteel Sports Supplements Inc. (Nichol is the founding partner and chief formulator), although Nichol swears it's a misnomer that his name is now equated with supplements.

"Nothing is as effective as eating real food," Nichol said. "I'm not advocating for kids at home drinking shakes."

Shakes and juicing are now a staple of the NHL player's diet. Convenient to consume, especially considering they are playing games at break-neck speed while most normal people are sitting down to dinner.

Some find it more palatable than others, but there is no debate that it goes hand in hand with the increased attention to training.

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One commonality among trainers, across the board, is the pride with which they talk about their clients.

Although the trainers spend often large chunks of time with these players in the summer, they send them off to training camp in September eagerly awaiting the results. They sometimes coordinate training and nutrition programs with team staffers once the season begins, but the NHL season is when the trainers get to witness the actual fruits of their clients' labor.

Prentiss expects a monster season from Shattenkirk, who whittled his body fat percentage from 17 percent to 8.2 percent. He called Carolina's Nathan Gerbe "pound for pound, the strongest guy" in his training group and described players such as Chris Kreider and Jordan Staal as "genetic freaks" for their impressive physical prowess.

Nichol has a similar affection for his crew, calling them "just a hardworking group of guys that work their asses off," and swears that his longtime client Carolina Hurricanes defenseman Jay Harrison, who is working toward a master's degree in chemistry, could sit down with anyone with a Ph.D. and give that person a "hell of a debate."

O'Brien, meanwhile, sounded ecstatic at the gains made by Calder Trophy winner MacKinnon, who added 12 to 14 pounds to his light frame, and gushed about the youngster's work ethic, calling it both "scary" and "dominant."

That said, O'Brien has one heck of a headliner to motivate his crew.

"Everything's really revolved around Sidney [Crosby]," O' Brien said. "He really sets the standard for everyone else. There's so much less I have to do because he's there. He's a guy that players look up to and his professionalism and attitude is so good that I rarely have to do anything to motivate other players. It makes it really, really easy from my perspective."

As for what is safe and healthy from a nutritional standpoint? Wright isn't shocked by the amount of body-fat reduction some players undergo in the course of one summer. Although a 10 percentage point loss in body fat would be a cause of concern for, say, a woman, with potential implications for her reproductive organs, it's not altogether unsurprising for an elite player, as long as he's not nutritionally deficient.

"Ten percent in one summer seems dramatic, but when we are talking about elite athletes, it's what they do," she said.