The Power of Variety: Why Changing Exercises Fuels Long-Term Progress

Throughout my clinical experience I have noticed one thing to be abundantly clear, creativity is essential in the rehabilitation process. Now, I bring this up because of some stark contrasts that I have seen between the ‘mill’ outpatient setting and the evidence intensive setting of our very own pro bono clinic PhysZou. Too many times in the standard outpatient plan of care did I witness patients doing the same exercise for weeks on end with seemingly little progress to show for it. Reflecting back now we can dive deeper into why changing exercises, movement patterns, or loads over time isn’t just about keeping things interesting, but a fundamental way to stimulate continued improvement, prevent injury, and keep the body adaptable. When variation is applied thoughtfully, it helps patients overcome plateaus and sustain long-term results.

Understanding Adaptive Resistance

No matter if we are talking to a recreational lifter, a prestigious athlete or a person that is recovering from an injury, our biological processes remain the same. Years of schooling have taught us that neural adaptation is where we typically see gains appear during the physical therapy treatment course as we are typically not with our patients long enough to show real physiologic improvements in muscle strength. This neurological adaptability is the foundation of progress but it also comes with a limitation known as adaptive resistance².

Adaptive resistance occurs when the body becomes too familiar with a specific exercise or movement pattern. Over time, the same muscles are recruited in the same ways, at the same angles, and under the same loads. Once the nervous system and soft tissues adapt fully to that stimulus, progress stalls. Strength gains slow, endurance plateaus, and performance can even regress. In the clinic, this translates to patient frustration as a result of provider inattention to how they are responding to prescribed exercises. Worse yet, repeating the same movement patterns indefinitely can lead to overuse injuries, as the same tissues experience wear and tear without enough variation in stress and recovery. This is one reason patients sometimes experience new aches or flare-ups after weeks of identical exercises.

The solution isn’t to abandon structure or start over, but to rotate and progress exercises purposefully. Using principles such as a 2 repetition sub-maximal strength assessment at regular intervals, tracking rate of perceived exertion and introducing change can all mitigate this. Simple examples might include changing the angle of a resistance band row, progressing a squat from double-leg to split stance, or shifting from controlled strength work to power-based movements as recovery improves. These subtle changes create new stimuli, helping the body continue adapting while reducing overuse stress.

The Science Behind Variation

Recent research from Hristovski and colleagues (2023) provides a fascinating systems-level explanation for why variation works and adaptive resistance is present. The authors describe long-term exercise adaptation as a process similar to physiological aging within the body’s networks. When an organism (or in our case, the neuromuscular system) is exposed to the same input repeatedly, it becomes more stable and efficient, but also less responsive. In other words, the body “learns” the exercise so well that it stops changing. This stability can be helpful for refining movement quality early in rehab, but over time, it limits further adaptation. The researchers refer to this as the body settling into a metastable state, meaning one that is too stable to grow¹.

Without getting too much into the weeds, this was demonstrated by Hughes et al. (2017) detailing the body’s adaptive responses to exercise are pathway-specific. For example, endurance work stimulates mitochondrial biogenesis through AMPK and PGC-1α signaling, while resistance training activates mTOR-dependent protein synthesis to drive hypertrophy. Overemphasis on a single mode of exercise can cause desensitization within these pathways, limiting further progress³. Clinically, strategic variation altering intensity, load, or exercise mode reactivates alternative signaling cascades and ensures continued adaptation.

The key to maintaining progress is what they call directed variation, purposeful changes to the type, load, or context of an exercise that “rejuvenate” the system and make it responsive again. Variation serves as a healthy disturbance that reawakens adaptability while preserving the positive gains of previous training. For example, a patient who has mastered a straight-leg raise might progress to resisted hip flexion in standing, then dynamic step-ups. Each new exercise builds on the last but changes the sensory, balance, and muscular demands ensuring the system doesn’t stagnate.

Clinical Application

While variation is critical, too much change can also hinder progress. The goal is not to replace exercises constantly, but to balance consistency with novelty. The body needs enough time to adapt to a movement before that movement evolves into something slightly new. Practically this can look like two to three exercise variations per movement category to maintain progress while providing enough familiarity for tracking improvements in strength or mobility. This might mean rotating between several pressing or pulling patterns, or periodically modifying the speed, surface, and equipment used.

However, this does not preclude the need for us to adapt to specific patient presentations and integrate our other rehabilitation principles. In populations such as older adults with dementia or those with substantial neurologic injury, the timeline for variation may need to be extended out to allow for neural adaptation to form a solid base. Variety should hold the hand of our principles of injury acuity, vital sign parameters, functional training and appropriate intensity. In essence, any recommendations we have regarding the variety of exercise should only be a part of your process for deciding what is right to do for your patient.

Parting Thoughts

Exercise variety isn’t just chasing novelty, it’s about respecting the science of how the body learns and adapts. When patients do the same exercises indefinitely, the nervous system and musculoskeletal tissues can grow complacent. Purposeful variation challenges the body just enough to keep it alert, adaptable, and progressing. 

As Hristovski et al. describe, the body’s capacity for change is like a living system that “ages” when it faces the same demands for too long¹. But the right amount of variety keeps that system young, flexible, and ready for new challenges. In the clinic or the gym, this can mean alternating periods of focused practice with phases of exploration. Encourage patients to master foundational movements, but then change how those movements are expressed in functional or more advanced patterns. This approach will help prevent plateaus and overuse, but also enhance long-term adaptability, independence, and confidence in movement.

References

1. Hristovski R, Balagué N, Stevanovski M. Long-term exercise adaptation. Physical aging phenomena in biological networks. Front Netw Physiol. 2023;3. doi:10.3389/fnetp.2023.1243736

2. Adding Variety to Your Exercise Program. Accessed October 19, 2025. https://www.uhhospitals.org/blog/articles/2020/08/how-to-beat-adaptive-resistance

3. Hughes DC, Ellefsen S, Baar K. Adaptations to Endurance and Strength Training. Cold Spring Harb Perspect Med. 2018;8(6):a029769. doi:10.1101/cshperspect.a029769

Disclaimer

We are current Doctor of Physical Therapy (DPT) students sharing information based on our formal education and independent studies. The content presented in this newsletter is intended for informational and educational purposes only and should not be considered professional medical advice. While we strive to provide accurate and up-to-date information, our knowledge is based on our current academic and clinical rotations and ongoing learning, not extensive clinical practice.