Coach's Corner: Training Density

In 1976 exercise physiologist Phil Gollnick published a series of research papers on the adaptation of muscle fibers to training. The findings at the time were groundbreaking, the study showed that long runs were beneficial because they caused the adaptation of both slow-and fast-twitch fibers. Essentially after 60 minutes of running the body began to recruit fast-twitch muscle cells similar to what athletes would see in a high intensity training session. Deep in the research however there was something else in the study that nearly everyone had overlooked: too much high intensity work was bad.

Everyone, that is, except Arthur Lydiard. The famed running coach and exercise physiologist was obsessed with finding out why too much intensity was bad. Through his work with many of the World’s top athletes, he discovered that high-intensity training was something one had to use sparingly and judiciously because it could just as easily break down an athlete as build one to a peak.

He just didn’t know why and so enlisted the help of Gollnick.

QUALITY WORKOUTS & RECOVERY

Gollnick began by studying the effects of high-intensity training on the mitochondria of muscle cells, the so-called "powerhouses" because they convert the body's available energy supplies into the muscle contractions necessary to allow the athlete to maintain a high rate of speed. What his experiment showed was that when the intense exercise depleted the mitochondria, the affected muscle cells took at least 24 hours to recover. The results implied that increased power from speed work doesn't come during the workout, but rather during recovery. If you don't allow for that recovery, you damage the muscle, not strengthen it.

Hardly groundbreaking research and it is something we all know as athletes and coaches: if you do high-intensity work or work that severely stresses your system, you don't recover very fast. Yet while many coaches develop training plans that prescribe to the “hard / easy” methodology made popular 50+ years ago, training density is a component that is often overlooked. The number and placement of intense training bouts should be considered just as much as intensity and volume, especially when training adolescents with little running history or athletic experience.

RECOVERY & ADAPTATION

“They are just not recovering between workouts…”

This was the consensus following a meltdown in one of our mid-season “check point” workouts. With a young, inexperienced team, both in running history and athletic background, our runners were having a difficult time adapting to the workload. This particular day the team looked fatigued, unmotivated and just holding 10k race pace seemed like a struggle. Without getting too in-depth regarding the stress reservoir and how the body responds to outside stresses our student-athletes were overwhelmed and the perception of their “life stress” was taking its toll. We had already modified our training toward “not getting hurt” rather than “training to win,” as we were tip-toeing around numerous injuries. Yet, even with the modified training the athletes were still not recovering.

For the record I feel strongly that at some point you need to put in the work. Rather than reduce volume or intensity further, we instead looked at using it more sparingly, increasing days between hard training bouts. Simply put our athletes were not adapting to the training stresses and needed more time between to properly recover and adapt.

Adding in greater spacing between training sessions allowed our athletes more time to recover and give a greater effort at key sessions. By simply adding the additional day or two between hard days athletes we were able to maintain training intensity and volume. Athletes saw increased confidence and motivation. With a varsity team full of runners with limited running history, the extra day also allowed much needed time to further develop their aerobic foundation.

There is no formula of proper spacing between workouts and will be largely dictated by the experience and genetic rebound ability of each athlete. While our team responded to reduced density, other teams I have coached thrived off a more condensed training program. Whatever the case, it is important to consider beyond variation in volume and intensity; we also need to consider training density and the spacing of hard workouts.

While, it's impossible to go through all of the attributes that go into deciding how much “space” is needed between workouts a few principles to consider are:

• Athlete Development / Age / Running History - Bigger the foundation, the more "stuff" the athlete can handle. You have to think long term: running daily in the off-season is directly correlated to what training you are able to do in-season.
• Event Type - Middle distance athletes generally have more "stuff" packed in, but overall volume is lower so total stress load is comparable.
• Ability of the Athlete to Recover - Everyone is different. How does an athlete bounce back from various types of workouts? (Years running, cumulative mileage & genetics are major determining factors here).
• Injury/Overtraining Risk - Train the athlete, not the event.
• Do You Need To Go There - Don't progress to adding extra things until they need to for adaptation. Beginning runners may need to spend time “learning to run.”

While there isn't anything groundbreaking about considering density or space between workouts, I think it's an important concept to consider when not just making your season training plan but when also making mid-season adjustments. We tend to focus on volume and intensity, when in reality it's the density of the work that often is the culprit between successful adaptation and not.