"Why are we jogging for an entire hour?," he asked with a suspicious look on his face.

I couldn't blame him for asking. Being a hockey player, he wants to get faster and more explosive. Trotting on a treadmill for 60 minutes at a mind-numbingly slow pace seems to work against this goal. It's also just not very difficult. At this intensity he could easily carry on a conversation or flip through the playlist on his phone without missing a step, so it certainly doesn't feel like anything productive is happening.

So how could training slow possibly be beneficial to an athlete that needs to be fast?

The direct answer is that training at a low heart rate for an extended period of time helps build the aerobic system, which will support an athlete's ability to recover from explosive, high-intensity exercise. The better the aerobic system, the better the response from high-end anaerobic training, and the faster the athlete can recover from it. It's also gentle on the body and has a great restorative effect.

But beyond this explanation, there's a deeper training principle at work.

Moving towards specificity

To understand it, it's critical to be aware that we don't train like this all the time. It's still early in the summer. But eventually we will shift into the explosive, high-speed interval-based conditioning that this athlete was probably expecting. But not yet.

In doing this, we adhere to the time-tested approach of gradually making training more sport-specific the closer we get to the competitive season.

It will still be three months until this athlete has to hit the ice in top form. That means for the next month, we will be working on the general qualities that will end up supporting specific demands.

Since hockey is a sport characterized by brief moments of explosive efforts interspersed with longer periods of recovery, our training should eventually mimic this. But right now we're focused on developing maximal strength and aerobic conditioning. This sets us up to maximize the benefits of the more hockey-specific training: sustaining short bursts of high-speed efforts.

However training doesn't always follow a slow to fast progression, that's not the principle, specificity is. In other sports, training can shift from fast to slow.

Jason Koop, a well-known ultra-endurance coach and author of the book Training Essentials for Ultrarunning, adheres to this principle by doing high-speed training early the offseason with his athletes, who are usually competing in events that require low speeds sustained over incredibly long periods of time.

"...many of my [runners] do flat, fast, high-intensity running very early in the year. They improve the least specific aspects furthest away from the event."

The underlying idea here is that by taking periods away from specific work to develop the supporting physiology allows the athlete to come back to the specific work with a better foundation and greater potential for improvement.

Eric Cressey, a baseball strength and conditioning expert summarizes this point well in describing part of his off-season approach:

"...when the off-season rolls around, most guys want a few weeks away from aggressive sprinting and change-of-direction work. Once they get their rest, we typically go to twice-a-week movement training sessions for October through December, usually on off-days from strength training...Once January 1 rolls around, the volume and intensity of sprinting increases, while the strength training program volume is reduced." (Read full article here.)

The value of variety

Another benefit of shifting the training focus is that it prevents burnout and keeps the athlete healthy. Exposing the body to the same type of work month after month, year after year has an inherent lack of variety and creates the potential for repetitive-based injuries.

Famed physical therapist Gray Cook has this to say on specialization:

"Specialization can rob us of our innate ability to express all of our movement potential. This is why I encourage highly specialized athletes to balance their functional movement patterns. They don’t so much need to train all movement patterns, they just need to maintain them. When a functional movement pattern is lost, it forecasts a fundamental crack in a foundation designed to be balanced. The point is not that specialization is bad—it only presents a problem when the singular activity over-molds to the point of losing balance."(Read full article here.)

I get that doing a slow jog for an hour isn't the sexiest workout in the world. But in my opinion it accomplishes a couple of important things. In addition to it creating a higher potential for improvement, it provides a break from the kind of work required of the athlete for most of the season. This little bit of variety is not only good for the body, making it more robust and resistant to injury, it's also good for the mind.

Despite the sideways looks I often get from athletes as I tell them they're going to be running for an hour, they often grow to enjoy it. Although it can be a little boring, the low intensity stuff is incredibly restorative. They often leave the training session surprised at how refreshed they feel, which can be a nice change of pace from the drained, beaten-down feeling that high intensity work often leaves them with.

The real win for me as a coach is when I see the athletes starting to buy into the principle of gradually moving towards more specific work. It shows me that along with their athleticism, their understanding of their sport and the training process in general is advancing to new heights.