Blog 1: Activate Before You Train
Part 1: Why Your Muscles Switch Off: And What That Is Costing You
Welcome to Activate Before You Train. Dr Keirstyn of Endurance Therapeutics introduces this three-part series on one of the most overlooked and highest-return habits in athletic performance. This series is not about warming up. You have probably already read about that. This is about something more specific and more important: making sure the right muscles are actually firing before you ask your body to perform.
It sounds simple. In practice, most athletes are training hard with muscles that are partially switched off. And they wonder why certain injuries keep coming back.
The Difference Between Warm and Activated:
A warm-up raises your heart rate, increases tissue temperature, and prepares your cardiovascular system for effort. It is important and worth doing properly. But a warm muscle is not the same thing as an activated muscle.
Activation refers to the neuromuscular process of waking up specific muscles and establishing the firing patterns your nervous system will rely on during training and competition. A muscle can be warm and still largely switched off. This distinction matters enormously in practice because the muscles most prone to switching off are usually the ones most critical to protecting the joints they surround.
The glutes are the most well-known example. Spend most of your day sitting and your glutes learn to be quiet. Walk into a training session without deliberately waking them up and they will stay quiet, while other muscles compensate. Those compensating muscles are the ones that eventually break down.
What Neuromuscular Inhibition Actually Is:
Neuromuscular inhibition is the process by which a muscle reduces its level of activation in response to sustained loading, prolonged positioning, pain, or disuse. It is a normal and protective mechanism but it creates real problems for athletes when the inhibited muscle is supposed to be a primary mover or stabilizer.
Research consistently shows that neuromuscular inhibition occurs rapidly. Studies on the gluteus medius have found measurable inhibition after as little as 20 minutes of sustained sitting. For the average desk worker who also trains, this means showing up to a run, a skate, or a swim session with hip stabilizers that have been quiet for hours and have not been deliberately reactivated.
The consequences are predictable:
The inhibited muscle underperforms: this produces less force and less stability than the movement demands
Synergist muscles step in to compensate: often the hip flexors, TFL, hamstrings, or lumbar erectors depending on the pattern
The compensating muscles accumulate load beyond their intended capacity
Injury develops in the compensating structure while the inhibited muscle continues to underperform
This is why I see so many IT band injuries, patellofemoral pain syndromes, and lower back problems that trace directly back to glute inhibition. The pain is in the knee or the back. The driver is the hip.
Which Muscles Switch Off Most in Athletes:
Neuromuscular inhibition follows predictable patterns based on posture, sport, and movement habits. These are the muscles I assess most consistently in athletes presenting with recurring injuries:
Glute Maximus and Glute Medius:
Inhibited by prolonged sitting, anterior pelvic tilt, and dominant hip flexors. The single most clinically significant inhibition pattern I see across all sports.
Serratus Anterior:
Inhibited in swimmers and overhead athletes, particularly those with rounded shoulder posture. When the serratus is quiet, the rotator cuff compensates and impingement risk rises significantly.
Vastus Medialis (VMO):
The teardrop-shaped muscle on the inner quad that stabilizes the patella. Inhibited in runners and cyclists with patellofemoral pain, often due to pain inhibition or dominant lateral quad patterns.
Deep Hip Rotators:
Inhibited in hockey players and runners with hip impingement patterns. These small muscles control femoral head position in the socket and when they are quiet, the hip mechanics suffer.
Lower Trapezius:
Inhibited in athletes with elevated and rounded shoulder posture. When the lower trap is switched off the upper trap overworks and cervical and shoulder injuries accumulate.
Why This Matters More Than Most Athletes Realize:
Here is the part that consistently surprises people. Strength training an inhibited muscle does not fix the inhibition. You can do three sets of hip thrusts on a muscle that is partially switched off and get a fraction of the training effect you would get from an activated muscle performing the same exercise.
This is one of the reasons athletes plateau in strength training or fail to transfer gym work to sport performance. The muscle is not actually engaging the way the exercise intends. Activation work before strength training is not just prehab, it is also performance optimization.
Research on pre-activation protocols has shown that targeted activation exercises before a training session increase EMG activity in the target muscle during subsequent loading, improve force production, and reduce compensation patterns. In plain language: you get more out of every rep when the right muscles are awake.
Up Next: The Exercises That Actually Make a Difference
Now that you understand why activation matters and which muscles are most commonly inhibited, Part 2 of Activate Before You Train gets practical. We cover the specific activation exercises that work, organized by sport and body region, and explain exactly what each one is doing and why it belongs in your pre-training routine. See you there.
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Wondering which muscles might be switching off in your own movement patterns? A clinical assessment at Endurance Therapeutics looks at exactly this — not just where you are strong, but where the right muscles are actually firing. Reach out to Dr. Keirstyn today to book yours.
📍 Endurance Therapeutics | Oakville