If you’re a runner who’s ever been injured, you know that an injury can feel like a big setback. The thought of being sidelined for weeks, maybe even months, can be disheartening, and let’s be honest – being injured sucks. Many runners worry about losing strength and fitness, and it’s common to wonder if you should even bother continuing with your strength program.
The good news is that even with an injury to your knee or ankle, you can still maintain, and sometimes even improve, strength on the injured side by working the other leg.
This technique is called cross-education. It is a powerful and often overlooked strategy that helps you stay on track during recovery. In this post, we will look at the science behind cross-education, how it works, and why strength training should still be part of your plan if you are an injured runner.
What Is Cross-Education?
Cross-education refers to the phenomenon where training one limb results in strength gains in the opposite, untrained limb. This happens because strength training is also creating neuromuscular adaptations, not just building muscle.
Your nervous system plays a major role in strength development by improving how your muscles coordinate, recruit motor units, and generate force. When you strength train the uninjured leg, your brain sends signals that strengthen motor pathways in both legs, even though only one leg is actively working. Research has shown that these neural pathways strengthen on both sides of the body when you train just one limb. This means your injured side also benefits from the training; pretty cool, right?
How Does Cross-Education Help Injured Runners?
One of the hardest parts about being injured is the lengthy rehab process. When a runner is injured, there is often a noticeable loss of strength, which can slow recovery. This is especially true for injuries to the knees or ankles because depending on the injury, even walking is limited.
By continuing to strength train the uninjured leg, you can:
- Maintain strength You may lose less strength on your injured side while it heals.
- Make your rehab more efficient By keeping neural pathways active, you can often regain motor control and strength more quickly once you are cleared to train both sides again.
- Limit muscle atrophy Cross-education helps reduce muscle loss on the injured side, which can lessen the long term impact of the injury.
For example, if you have injured your knee, you might assume squats and lunges are off the table. You may still be able to perform single leg versions of these movements on your healthy leg. These exercises can help maintain muscle mass and strength in both legs by engaging the neural circuits that control movement, even though only one side is loaded.
The Science Behind Cross-Education
Strength gains come from both muscular and neural changes. Cross-education is mostly driven by the nervous system. This process, called neuromuscular adaptation, includes several key factors:
- Neural drive: The ability of your nervous system to recruit and activate motor units to generate force.
- Motor control: How effectively the nervous system coordinates muscle movements.
- Muscle coordination: How different muscles work together to produce smooth, efficient movement.
Research shows that strength training one limb can improve these factors in both the trained and untrained limbs.
In practical terms, if you keep training your healthy leg, your injured leg doesn’t lose strength as rapidly as it would with complete rest. This is one reason strength training is so valuable for runners. Whether you are injured or healthy, it supports performance and can help reduce the risk of future injuries.
How to Implement Cross-Education in Your Strength Routine
So, how do you apply cross-education in real life when you are injured?
1. Focus on unilateral exercises
Unilateral strength exercises, where you work one limb at a time, are ideal for cross-education.
For the healthy leg, you can use exercises such as:
- Single leg squats or split squats
- Single leg deadlifts
- Single leg step ups or rear foot elevated split squats
You can also keep training your upper body with presses and rows to maintain overall strength while your lower limb heals.
Make sure to always follow any restrictions given by your physiotherapist, physician, or surgeon.
2. Adjust the intensity
It can be tempting to push hard on the healthy side. You still need to respect the overall load on your body, especially if your injury affects balance or stability.
Aim for controlled, moderate intensity exercises that:
- Challenge the muscles without causing pain or strain elsewhere
- Allow you to maintain good technique
- Don’t leave you excessively sore for several days
The goal is to maintain and support strength, rather than chase new personal bests while injured.
3. Keep your core working
Even with an injured knee or ankle, you can usually continue training your core.
Good options include:
- Front and side planks
- Dead bugs
- Bird dogs
- Glute bridges (within your comfort and medical guidelines)
These exercises help maintain trunk stability, which is important for efficient running when you return to full training.
4. Work with a professional
If you are unsure how to safely integrate cross-education into your recovery plan, consider working with a professional. A Clinical Exercise Physiologist or Physiotherapist can help you:
- Choose appropriate exercises for your specific injury
- Set safe loading and progression
- Balance strength work with your rehab exercises and any modified running
This reduces guesswork and helps you feel more confident that your training is supporting your recovery, rather than competing with it.
Strength Training: Key for Recovery and Prevention
Injury recovery can feel slow, but cross-education gives you a proactive tool. By continuing to train your healthy side, you are:
- Helping to maintain strength in the injured limb
- Supporting a smoother transition back to full training
- Keeping strength work in the mix, which is important for performance and injury prevention
Pausing running doesn’t mean you need to pause strength training. There is still a lot you can do to stay strong, maintain fitness, and keep your body as prepared as possible for your return to running.
Conclusion: Keep Moving Forward with Cross-Education
Your body is more connected than it might seem. Your nervous system has a major role in keeping you strong, even when one side is injured. Cross-education is a simple and effective method to help you maintain strength on both sides of your body during injury recovery.
If you are unsure how to adjust your strength routine, manage injury recovery, or balance training with the rest of your life, coaching can help.
You can:
- Join Runner’s Strength Lab™, my strength program for runners that focuses on smart, progressive strength and prehab work.
- Book a one-on-one consultation for a personalised plan that takes your injury, goals, and schedule into account.
Related Content:
- Strength Training for Runners: Why 2–3 Days a Week Is All You Need
- Running Injuries 101: How to Prevent and Manage Niggles Before They Sideline You
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References:
- Howatson G, Zult T, Farthing JP, Zijdewind I, Hortobágyi T. Mirror training to augment cross-education during resistance training: a hypothesis. Front Hum Neurosci. 2013 Jul 24;7:396. doi: 10.3389/fnhum.2013.00396. PMID: 23898251; PMCID: PMC3721498.
- Andrushko JW, Lanovaz JL, Björkman KM, Kontulainen SA, Farthing JP. Unilateral strength training leads to muscle-specific sparing effects during opposite homologous limb immobilization. J Appl Physiol (1985). 2018 Apr 1;124(4):866-876. doi: 10.1152/japplphysiol.00971.2017. Epub 2017 Dec 14. PMID: 29357520; PMCID: PMC5972467.
- Manca A, Dragone D, Dvir Z, Deriu F. Cross-education of muscular strength following unilateral resistance training: a meta-analysis. Eur J Appl Physiol. 2017 Nov;117(11):2335-2354. doi: 10.1007/s00421-017-3720-z. Epub 2017 Sep 21. PMID: 28936703.
