Running Injuries: Load vs Capacity Explained

If you're a runner, you may have heard about the concept of load vs. capacity. But what does it mean? How will it help you prevent running injuries?

Load vs. capacity helps runners gauge the stress (load) that their bodies handle during training against their ability to handle that stress (capacity). When load exceeds capacity, your risk of injury increases.

By learning how to balance these elements, you can improve your running performance, improve your endurance, and reduce the likelihood of injuries.

In this article, we'll explore everything that you need to know so that you can progress with your training safely and effectively. Let's dive in!

What is Load?

Load refers to the physical and physiological stress placed on your body when you're training as a runner. Several factors influence how much strain your muscles, tendons, ligaments, and bones have to endure.

Types of Loads

While it can be tempting to hit the paths or treadmill hard as a beginner, carefully managing the three interlinked load types can help you steadily build your endurance while reducing your risk of injury. These include:

  • Training Volume: This is the total amount of running you do, measured in kilometres or time spent running. Increasing your volume too quickly is a common risk factor for overuse injuries.
  • Intensity: This is the level of speed and effort during your workouts. High-intensity sessions like sprints or hill repeats exert a greater load on your body compared to a gentle jog.
  • Frequency: How often you run each week also contributes to your load. If you run several days a week, you're increasing your load and reducing your recovery time. If you don't manage your training regimen properly, this can potentially lead to an increased risk of injuries.
  • Type of training: Sprinting and plyometric workouts work your body more neurally and fascially, whereas longer runs work more cardiovascularly and muscularly. Each in excess can lead to different types of injuries.
running on suburban street

What is Capacity? 

Capacity refers to the ability of your body's tissues — muscles, tendons, ligaments, and bones — to withstand the stresses of running. It's essentially how much load your body can handle without getting injured.

Factors Influencing Capacity

There are a few capacity factors that will influence how you, as a unique individual, handle the physiological stress of running, including:

  • Age: As you age, your capacity can change due to decreased muscle mass and bone density, impacting your ability to handle training loads.
  • Fitness Level: A higher fitness level generally leads to a higher capacity. Regular training enhances muscle strength, endurance and flexibility, giving you greater resilience against injuries.
  • Previous Injuries: A history of injuries can affect your capacity. Injured tissues may not return to their original strength or flexibility, which can limit your capacity and increase the risk of injury if not properly managed and rehabilitated.

The Relationship Between Load and Capacity 

The balance between load and capacity is fundamental in avoiding running injuries. An imbalance happens when the load from your training exceeds what your body's tissues can handle, leading to stress and potentially even injury.

How Imbalance Can Lead to Injuries

Finding that perfect middle ground can be a challenge, but it’s important to avoid both overtraining and undertraining.  

When you increase your distance, intensity, or frequency too quickly without proper adaptation, the excessive load can lead to overuse injuries like shin splints or stress fractures or tendinopathies.

Funnily enough, too little load can lead to decreased capacity, making your body more susceptible to injury when your load suddenly increases.

woman overextended during running

Why You Need to Find the Right Balance

Maintaining a balance helps prevent the common traps of both overuse and underuse injuries. By aligning your load with your capacity, you can have a much more sustainable and healthy training regimen.

Finding the right balance also promotes better performance. Runners can progressively increase their loads as their capacity builds, leading to improvements in speed, endurance, and running efficiency.

Identifying Signs of Imbalance 

Recognising the early signs of imbalance between your load and your capacity is crucial for avoiding injuries and maintaining optimal health. Being aware of these symptoms can help you adjust your training plans effectively.

Common Signs of Imbalance

It’s important to listen to your body, and while a little discomfort during exercise is to be expected, if you notice any of the following, it is time to hit pause and reappraise your running schedule.

  • Persistent Pain or Discomfort: Pain that doesn't go away with regular rest and recovery measures is a clear sign of overload.
  • Decreased Performance: If you notice a sudden inability to meet your previous performance levels, it might be a sign that your body is overwhelmed.
  • Fatigue: Excessive tiredness, not just typical post-run weariness, can suggest that your training load exceeds your recovery capacity.
  • Mood Changes: Irritability and lack of motivation can also be symptoms of overtraining, reflecting an imbalance of your capacity and load.

When to Scale Back

Once any signs of imbalance are noticed, it's crucial to reduce your training load to make room for proper recovery. Pushing on through imbalance can lead to injury and greater discomfort or pain. So, what can we do about it and how do I know how much to cut back?

If signs of imbalance are persistent or recurring, seeking advice from physiotherapists or sports medicine professionals can help you determine the appropriate adjustments needed in your training regimen. Periodically assessing your training intensity, volume, and frequency is essential for making sure they align with your evolving capacity and lifestyle factors, like stress and sleep quality.

ankle joint during running

Strategies to Manage Load and Enhance Capacity

Effectively managing your training load and safely enhancing your capacity is key to maintaining your health and improving your performance. Here are some practical tips and techniques to help you achieve a healthy balance.

Practical Tips for Adjusting Your Training Load

It may seem obvious that we should avoid overloading our bodies, especially at the beginning of our running journey, but sometimes enthusiasm can override discipline. To avoid overloading your body, follow the 10% rule, increasing your running volume by no more than 10% per week. Sometimes, slow and steady does indeed win the race.

Incorporating a mix of high-intensity and low-intensity workouts, as well as strength and flexibility training, can also help distribute the load more evenly, while also ensuring that we are strengthening our whole body.

At all stages of your running journey, as both a beginner and an expert, take the time to get in tune with your body and pay attention to how it feels. Excess fatigue or discomfort can indicate that you need to scale things back temporarily.

Techniques to Safely Increase Your Capacity

We all want to see progress in our training and progress comes from consistency. Regular, moderate training helps build tissue resilience over time, increasing your overall capacity. Doing less but more often is more effective than doing one super intense day per week.

On the other side of the consistency coin is getting adequate and regular rest and recovery. Prioritise your rest days and make sure you get enough sleep each night to allow your body to recover and rebuild.

Consistent training and rest are both important and so is consistent and proper nutrition. Fuelling your body with the right nutrients supports tissue repair and growth, which is essential for increasing your capacity.

Getting this consistent balance right for your own unique needs can be a little tricky, so consider getting professional guidance as part of your overall fitness strategy. Consulting with physiotherapists can provide tailored advice on safely increasing your capacity based on your specific needs and goals.

woman running marathon

Finding Your Balance for Optimal Running

Understanding and managing the balance between load and capacity is crucial for avoiding injuries and enhancing performance.

By recognising the signs of imbalance, adjusting your training load responsibly, and gradually increasing your capacity, you can maintain a healthy and progressive running regimen.

Embrace these principles in your training approach. Pay attention to your body's signals, incorporate sufficient recovery, and seek professional guidance when necessary.

With this knowledge, you're well-equipped to achieve your running goals and keep injuries at bay!

Get Expert Help Today

Ready to optimise your training and prevent injuries? Get in touch with All Elite Physio to get tailored advice on how to balance your load and capacity.

Our expert physiotherapists are here to guide you every step of the way. Reach out now and take the first step towards smarter, safer running!