If you've ever been handed a list of exercises after an injury, you've probably wondered: "Do I need to do these on both sides, or just the side that hurts?"
It's a great question, and honestly, the short answer is... It depends.
But that answer isn't always as simple as it seems, so here's why working both sides is the smarter approach (even when only one side is injured).
Your Body Is More Connected Than You Think
Your brain and nervous system treat your body as one connected system, not a collection of separate parts. When one side is injured, your whole body starts to adapt to it, not just the area that's hurt.
Research shows that when you consistently exercise one limb, your opposite, untrained limb also gets stronger. This phenomenon is called the cross-education effect, and it has been well documented in exercise science for decades.
What this means practically: if your right knee is injured and you strengthen your left leg, your right leg actually benefits too (even before you can put full stress or pressure on it).
Why Training the Uninjured Side Matters
Here are some science-backed reasons your physiotherapist may have you working both sides:
1. It Reduces Strength Loss on the Injured Side
When you're injured and can't fully use a limb, muscle loss (called disuse atrophy) happens quickly. Training the uninjured side helps slow down that muscle loss on the injured side through cross-education.
2. It Keeps Movement Patterns Intact
Your brain stores movement patterns. When you keep reinforcing a movement on your healthy side, your nervous system maintains that motor program for both sides. This makes retraining the injured side much easier and faster once healing allows.
3. It Prevents Overcompensation Injuries
When one side is injured, the other side naturally picks up the slack. Without intentional strengthening, the uninjured side can become overloaded, leading to a second injury. Balanced training protects you from this common pitfall.
4. It Supports Better Recovery Outcomes
Studies have shown that patients who train both sides during rehabilitation tend to recover strength and function faster than those who rest the uninjured side entirely. Your healthy side is a tool, use it!
So, When Should You Focus Only on the Injured Side?
There are situations where your physical therapist may specifically target the injured side with certain exercises. This is common when:
- Re-establishing neuromuscular control — retraining the brain-muscle connection that gets disrupted after injury
- Addressing specific movement compensations — correcting the way you're moving to protect the injured area
- Reducing a significant strength or flexibility imbalance — when one side has fallen noticeably behind
- Working through a specific stage of tissue healing — some exercises are prescribed based on exactly where you are in the recovery timeline
In these cases, you may be doing more reps or sets on the injured side, or doing exercises that are specifically tailored to its current limitations.
A Practical Example: Ankle Sprain
Let's say you sprained your right ankle. Here's how a well-rounded program might look:
| Exercise | Both Sides? | Why |
|---|---|---|
| Calf raises | ✅ Yes | Maintain strength bilaterally |
| Balance/proprioception work | ✅ Yes (more reps right) | Rebuild stability on injured side |
| Range of motion circles | ✅ Yes | Keep left side mobile, retrain right |
| Single-leg strength loading | ⚠️ Progress carefully | Load the injured side as tolerated |
| Hip and glute strengthening | ✅ Yes | Support the whole kinetic chain |
The Takeaway: Balance Is Usually Best
Your injury may be on one side, but your recovery is a whole-body effort. Unless your physical therapist specifically tells you to skip the other side, doing your exercises bilaterally is almost always beneficial.
If you're ever unsure, the best thing you can do is ask your physiotherapist directly. A good therapist will always be able to explain why an exercise is prescribed, which side to do it on, and what you're trying to achieve.
Ready to Build a Smarter Recovery Plan?
At Renew Wellness, we don't just give you a list of exercises; we explain the why behind every single one. Our evidence-based approach means your rehab is built around what the science actually supports, tailored specifically to your body and your goals.
📞 Book your appointment today and start your recovery the right way.
Because feeling better shouldn't be a guessing game.
