Nylon Calculus: What exactly is load management?

Understanding the science of load management can add context to the discussion about the positives and negatives of resting players.

Andrew Patton has over ten years of experience as a strength and conditioning coach working with athletes ranging from Olympians and All-Americans to regular recreational athletes. He is also involved in strength and conditioning research relating to injury risk factors from strength training. Andrew is currently a Ph.D. candidate at Johns Hopkins Bloomberg School of Public Health in Exposure Science and Environmental Epidemiology. He also writes about the NBA at various places on the internet.

Since Kawhi Leonard was announced to miss the first leg of a back to back for the second time this season, and the subsequent fine given to Doc Rivers discussing that situation, there has been a substantive amount of poorly informed discussion on the idea of load management in the NBA. Across the cultural “old school vs. new school” camps, there is a limited understanding on what load management actually is from a human performance standpoint.

This article will cover the generalities and scientific principles behind the concept of “load management”. While this article will be written with a basketball context, it is applicable across sports/activities. However, it is a brief overview of an extremely complex topic. For additional reading on fatigue and recovery concepts, see the works cited section.

Load

The first step in the load management journey is to define what load actually means. Broadly, it is the summation of physical and mental stressors that happen to a player as a result of training, competition, and life. Casually shooting around for an hour is load, playing 48 minutes in an NBA game is load, lifting weights is load, having a family issue is load. Moving forward, we will ignore mental load/stress, as quantifying that is outside the scope of this article. The physical load on a player can at the most basic level be broken into the following sections

1. Volume

Literally the physics definition (work = force * distance), this encompasses “how much” an athlete has done. There are absolute ways to measure this (calories, joules, etc.) or relative measures that are expressed as a proportion of how much compared to a baseline is performed. Keep in mind that Trey Burke and Joel Embiid each running one mile at the exact same speed are not performing the same amount of work, and are therefore experiencing differing absolute loads (and likely relative loads). This is often measured by GPS tracking so teams have an understanding of exactly how far a player has traveled (and how fast) in the course of training/competition.

2. Intensity

This can be thought of how hard a specific stressor was, either in relative or absolute terms. An NFL middle linebacker player and an NBA point guard performing the same lift with 200 pounds in the gym would produce the same amount of physical work, but the level of difficulty and amount of fatigue generated for the point guard (weaker) would be substantially higher. However, if the lift was set to 70 percent of each player’s maximal ability, the relative intensity would be the same. A common metric for tracking this in on-court situations is heart rate and respiration rate.

3. Schedule

This encompasses the frequency and density of the load. Playing three basketball games in seven days is fundamentally a different situation than playing three basketball games in one day, despite the same number of events.

So what?

Ultimately, why we care about load is that application of load results in fatigue, which is defined as “the disruption of physiological systems that leads to a decrement in athletic performance” (Hoffman, Israetel and Davis 2019). Instead of load management, the term fatigue management is really a better term and is one that has been used for a long time prior to the NBA bringing load management to the masses.

With the application of load, there is fatigue generated, which on a biological level is minute (hopefully) amounts of tissue damage. How much damage is caused is a function of our three parameters above, but the explosive activities such as jumping and landing (especially on hardwood) are highly fatiguing. A good example of this in action is LeBron’s famous Versa climber workouts, which were a way of increasing cardiovascular fitness with zero jumping, landing, or impacts. Load is required to train to play in the NBA, load is also required to compete in the NBA, therefore fatigue is inevitable. What is done with that fatigue is the next part of load management.

Management

It’s important to note that not all biological processes or tissues are fatigued/disrupted at the same rate, nor do they recover at the same rate. Depleting glycogen, the primary energy storage form of glucose, to the point of performance decreases occurs much faster than damaging bones to the point of performance decreases (excluding acute injury). However, this is also true for recovery as well, where replenishing glycogen can be fixed with dinner and healing bone damage takes far longer. Figure 1 below shows an approximate time scale for fatigue/disruption accumulation and recovery.

Via: Israetel, Hoffman, and Smith (2018)

Now with an understanding that fatigue is inevitable (and required) during the NBA season, and that this fatigue if unchecked can result in performance decreases based on biological damage, it is now time to discuss fatigue management concepts.

Maximum Recoverable Load

This is the maximum total load (practice, training, lifting, games, etc.) an athlete can tolerate without decreases in competition performance. There comes a certain point where doing more is detrimental, and the MRL (synonymous with MRV for strength training) is that point. This load is high enough where over time, the athlete is not recovering and their performance will suffer. This MRL is variable by individual and by time frame. If an athlete is routinely in exceedance of their MRL, they need to reduce fatigue in order to ensure that performance returns to normal. The simplest way to reduce that fatigue is to reduce load in practice, training, or competition. Figure 2 presents the general hierarchy of fatigue reduction. Doing less is more in this case.

Via: Hoffman, Israetel and Davis 2019

Given that competition is by far the most fatigue-inducing activity, it makes sense that reducing those provides the biggest return.

Proactive vs. Reactive

With regards to fatigue, it is generally preferable to be proactive instead of reactive, especially over the course of 82 game. The time cost to recover from excess fatigue is almost always going to be greater than the time cost to prevent that excess fatigue in the first case. The way to handle that is to understand how fatigue can be predicted, determined in real-time, and after the fact. Figure 3 (one of my favorites) breaks out fatigue indicators across those three time-points.

Via: Hoffman, Israetel and Davis 2019

If you are routinely modulating the fatigue of your athletes based on pain or injuries, you are extremely doing it wrong. Additionally, it is useful to measure some of the above variables in a quantitative manner (jump power, training volume, heart rate, etc.), as high level athletes are notorious liars about how well they are feeling due to a lifetime of being told that “complaining” is bad as well as a desire to play.

All the information above was provided under the assumption that an athlete is healthy, so their fatigue accumulation is a generic whole-body sense. If an individual has an active injury or a history of injury, their fatigue and load need to be modulated to the weakest link in the chain. For a totally random example, if an athlete has been battling a knee/quadriceps injury for the better part of three seasons, that athlete should have their load limited by the MRL for that specific body part, not for anything else.

Now where the rubber meets the road is smashing together knowledge about an athlete’s load (specific to that individual) with appropriate fatigue management strategies. I’ll skip writing 5,000 words on recovery modalities, so for more information on that, go read the books in the works cited. The coaching, strength and conditioning, and medical staff on an NBA team should plan together to understand where in the schedule it’s likely that there will be either acute or chronic high fatigue/high load situations and have plans in place to mitigate some of that fatigue. Additionally, the staff should be flexible to disruptions in that plan that will certainly arise, and modulate the response as necessary.

NBA players are bigger, stronger, and faster than they have ever been. They also come into the league with more miles on them due to the increased pace of play, youth specialization, and AAU ball. With billions of dollars in resources and cutting edge performance data monitoring it makes sense that teams and athletes would be concerned about the season-long goals and not any single game on the schedule.

While there is nothing wrong (in a vacuum) with playing a first-round draft pick 40 minutes in a given night, there becomes a problem if that becomes the norm and exceeds the player’s capacity to recover for performance or health reasons. Scientifically appropriate fatigue management is here to stay for good reason, and those who oppose it due to toughness (barf) or work ethic related issues are fundamentally missing the point of sports, which is to achieve success on a team and individual level, not to attempt to live up to incorrect ideas about our past athletic heroes. How the NBA should handle that regarding scheduling and television is far beyond my knowledge.

“It is important to note that [fatigue recovery] strategies and techniques are not sufficiently powerful to overcome stupid coaching, bad planning, or lack of talent.” — Dr. William Sands (Hoffman, Israetel and Davis 2019).