By Neal Prokop, Sport Performance Specialist
As restrictions lift and athletes start getting back into the gym and their respective training environments, it’s important to make sure they don’t do too much, too soon. Simply put, athletes who increase their training loads too quickly, are at a greater risk of injury.
Load management has become a commonly used term, and you’ve likely heard the concept of managing workloads discussed on sports radio or television. If you followed the Toronto Raptors en route to their first NBA championships, you would have certainly heard about Kawhi Leonard, and the approach that the team took in preparing him for the playoffs. Load management sounds straightforward…train hard, and take more days off. In reality, sleep, stress, nutrition, competition schedule, training variety, volume, duration, and intensity adjustments are only a few of the variables that coaches consider when planning training loads and assessing their athletes’ load tolerance.
In this article, we’ll discuss what training load is, different ways to measure or monitor load, why load management is important, and important considerations for progressing training loads.
We know that managing training loads helps improve the development of athletic abilities, increases performance, and reduces the athlete’s risk of injury. Even though injuries cannot be predicted with crystal ball accuracy, studies continually show that sudden increases in training volume, intensity and/or the frequency of sessions increase the likelihood of an injury occurring whether it occurs in the current session, or a future competition and training session.
As an athlete, coach or parent, you need to reflect on the potential benefits and potential risks of making rapid adjustments to your training loads and schedule. “Shock Blocks”, or a block of significant changes in training loads above what the athlete is accustom to have a purpose . . . but the athlete’s load tolerance must be built. I hope this article helps provide insight and information to help guide you in making the best training decisions possible as you transition out of lockdown.
What is Load? How Do I Measure It?
The load placed on an athlete is a measure, or sometimes an arbitrary measure, of the demands placed on an athlete over a particular time period. The time period could be a training session, a week, month, or season. There are two types of load: external and internal load monitoring.
External load refers to the act of ‘performing work’ in preparation for or carrying out a task and activity.
- EX: the amount of weight lifted, the number of miles ran, power-output, number of sprints, or number of reps the athlete completes etc.
External load monitoring helps understand an athlete’s capabilities and capacity. Over time, as the athlete develops, coaches adjust these external load measures to contribute to their athlete’s progress. Typically, the external load increases. We want to see our athletes improve so that they lift more weight, run more miles, increase their power-output, or complete more reps.
Internal load refers to the physiological, psychological, or biomechanical response to performing the work.
- EX: how the athlete feels and how the athlete’s body reacts when training
Rather than telling us what the load, or work, is…internal load measurements try to tell us how the athlete’s body is handling the external training loads. The benefit of measuring internal load is that it can be important in determining the appropriate stimulus for adaptation, we don’t want too much, or too little work. We want just the right amount.
A very common and well-received way to measure internal load is through a simple questionnaire. For example, what was the athlete’s perceived level of exertion? On a scale of 1-10, or 1-20, have the athlete rank how hard the session was. Sometimes as coaches you want sessions to be tiring, perhaps an 8/10 or 9/10, and other times we might want a recovery-type session at a 2/10 or 3/10.
Heart-rate, heart-rate variability, movement velocity, sleep quality and duration, and measuring changes in psychomotor speed or reaction such as a 10m sprint or vertical jump, can help you understand how athletes are internally handling the changes in training loads prescribed to them, and when they might be training in a more fatigued state.
How Much Load Progression Is Optimal?
It depends. Whenever we talk about the load, we need to think about Load, relative to capacity.
First, an athlete’s load tolerance depends on many intrinsic variables. Some are within an athlete’s control and others are not. Age, flexibility, previous injury, body composition, skill level, nutrition, sleep, stress, and hydration could all impact the training load that an athlete can tolerate in a particular session, training week, or month. An athlete’s maximum strength can commonly fluctuate up to 10-20% in a given week simply based on some of these variables, which is why some trainers have turned to measuring and prescribing the velocity of the movement at particular points in the season, rather than prescribing the actual weight or number of reps to be lifted. The athlete’s health and routine away from their training environment are very important in determining their load tolerance. 
Second, load progression depends on three main variables:
- what is the athlete’s load capacity or tolerance currently? (the “floor”)
- where does the athlete need to get to “the ceiling”?, and
- how much time does the athlete have?
The more time we have to get athletes from their floor to their ceiling, the more gradual our load increases can be. Often athletes or coaches plan a training program from start to finish. However, conceptually the approach might be best planned from finish to start. Hopefully, we have an idea of the required capacity from the athlete to be at their peak performance.
For example, the required capacity for a race might be to run 20 miles, at a 6 minute/mile pace. Perhaps at this given moment, the athlete’s capacity is 5-miles at an average pace of a 12 minute/mile. If an athlete has 30 weeks to get to their ceiling, they would need to improve by ~2 miles per week, and shave 12 seconds off each mile. We now have an idea of the progression rate and how quickly we need to progress the athlete.
Third, load progression depends on the athlete’s floor of safety, and ceiling of safety. Some will use the 10% guideline, stating that you can safely increase training loads by 10% each week. While this may be an appropriate guideline, the load relative to the athlete’s capacity is important. If an athlete’s load is low relative to their capacity, they are at their floor of safety, and increases in training load can progress more quickly. Alternatively, if an athlete is close to their ceiling of safety, a 10% training load increase might be too much. You can’t put water in a glass that is already full, so maybe a smaller increase in training load is all the athlete can safely handle.
So unfortunately there isn’t a generic answer to “how much load or progression is optimal”? It depends on the athlete. Always remember to think about the load relative to capacity.
The Acute to Chronic Workload Ratio
Keeping everything you’ve just read in mind, the acute to chronic workload ratio helps us account for the concept of load relative to capacity by giving us a measure that we can use for comparison, guidelines, and analysis.
Here are three key things to remember:
- Acute Workload: The load an athlete did during the past seven days
- Chronic Workload: The load an athlete did during the past 21 or 28 days
- Acute to Chronic Ratio: is calculated by dividing the Acute Load by the Chronic Load
This chart adapted from Tim Gabbett (2016) illustrates a good acute to chronic workload ratio for rugby athletes, and has a correlation coefficient of .53, meaning that 53% of the injury risk could be explained by the change in acute to chronic workload. Each sport has different sweet zones and danger zones, but the underlying message is that athletes that increase their load too quickly or do more training than they are used to, are at a greater risk of injury.
When you use the acute to chronic ratio, you are asking yourself “have I built the athlete’s load tolerance high enough so they will be able to withstand the next week’s training load?”. In other words, is the athlete taking on significantly more load than they are used to.
Here’s an example;
Let’s say we’ve progressed the athlete to a chronic training load of approximately 2850 units. Using Gabett’s chart above, the potential acute to chronic ‘danger zone’ is at a ratio of 1.5, or in our scenario, 4275 units. When we analyze the chart, we may decide that we want another week between 3000-4000 units to build the athletes chronic load, before we progress the athlete past the 4275 mark. Perhaps we decide that 4275 units is just a little too much, a little too soon!
How Much Time Do I Need, and How Much Time Can I Take Off
One final point: the lockdown through the COVID-19 pandemic has forced athletes to find creative ways to maintain their fitness from home and it has been important for athletes to take initiative to maintain their capacity and athletic abilities. A final chart below, adapted from Purdam (2015), illustrates the number of weeks needed to ramp up training, to mitigate injury risk, relative to the amount of time the athlete took off.
Here’s how to read the chart:
The circle in the bottom left: If the athlete took a three-week training break, but maintained 80% of their capacity, they would need approximately one week to work their way back up.
The middle circle: If the athlete took a five-week break, but maintained 40% of their capacity, it would take approximately four weeks to ramp up their training and get back on track.
The chart illustrates the importance of training year-round and maintaining athletic capacities, even during an off-season or holiday break. When athletes stop training altogether, the length of time to safely progress training loads increases, and rushing this process by increasing volume and intensity too quickly can increase the risk of injury.
In Summary
High training load and volume isn’t necessarily a problem. In fact, higher chronic loads are associated with lower injury risks because athletes have built up a higher load tolerance. The issue, or risk, that often surrounds high training loads, is when determining how the athlete builds their training tolerance. Using some of the approaches discussed in this article can help ensure athletes are prepared for the training loads they can progress towards. You can apply these principles when returning to train following an off-season break, returning from injury, or during your yearly training plan to minimize training spikes at tournaments and training camps.
As you come out of the lockdown and gradually return to training and play, reflect on the potential benefits and risks of making rapid adjustments to your training loads and schedule, and be sure to reach out to Sport Manitoba Performance for assistance in your program design.
Until next time, stay safe, and happy training!
