Unlocking Flexibility: The Power of Static Passive Stretching

A lot of what you see on social media highlights dynamic movements and active stretches to improve flexibility. However, static passive stretching—those long, still holds—remains a cornerstone of practical flexibility training. Despite some misconceptions, when done correctly, it's a highly effective way to increase stretch tolerance, reduce resting stiffness levels in the muscle-tendon unit, and enhance tissue health.

As a mobility coach and stretch therapist, I am constantly using static passive stretching with my clients, not only because it is effective but also because it is highly controllable and accessible. 

This post will explore static passive stretching, the different types, and practical tips for optimizing your stretching routine.

What Is Static Passive Stretching?

Static passive stretching involves holding a stretch without using active muscle contractions. Once in position, you try to ‘relax’ into the stretch. However, it is essential to recognize that the antagonist muscles are under a tensile load in static passive stretching, so the stretching muscles might not feel very relaxed!! 

To get real flexibility improvements from passive static stretching, you must work at intensities that are at least a little uncomfortable. So, ‘relaxing’ into the stretch can take some concentrated effort—it is, therefore, a bit of a misnomer to think of it as a relaxed type of stretching.

Types of Static Passive Stretching

There are two main approaches:

• Constant Angle Stretching:
  The defining characteristic of constant angle stretching is that the joint angle stays the same throughout the stretch. Due to stress relaxation, the tension in the stretched muscles decreases over time and the intensity of the stretch will go down throughout the duration of the stretch in healthy tissue.
• I mostly use this type of stretch in two situations:  
  • Beginner clients who are getting used to the discomfort of flexibility training: Moderate intensity, constant angle stretching can be a great way to build confidence and tolerance to stretches before moving onto more advanced options and greater intensities. 
  • Intermediate/advanced students trying to build tolerance to a specific position—the splits, for example: Typically, these students perform constant-angle, static passive stretches at much higher intensities. 

• Constant Torque Stretching:
  The second type of static passive stretching is constant torque stretching. Constant torque stretching can be thought of as continuous intensity stretching. Adjusting the joint angle to go deeper into the stretch as the tension in the muscle decreases over the duration of the stretch.  Chasing the intensity of the stretch ensures that the force remains consistent throughout the set. This method of stretching has been shown to be more effective for reducing tissue stiffness and increasing flexibility if done at sufficient intensity and for an adequate duration.

Top Tips to Maximize Your Static Passive Stretching

1. Optimize Tissue Temperature
Research shows that collagen fibres stretch more effectively when tissues are warm. Aim for a 10-15-minute cardio warm-up before stretching, and hold your stretches during the cool-down phase. 

Why it works: Warmer tissues (~39°C) are more pliable, allowing for more effective stretching.

(Rigby & colleagues 1959 and Lehmann & Colleagues 1970 support the idea that collagen structures can be permanently elongated with minimal structural weakening when stretches are performed at elevated body temperatures ) 

2. Sufficient Duration
Hold each stretch for a minimum of two minutes (either in one go or cumulatively over multiple sets). Shorter durations may not trigger the structural changes necessary for long-term improvements. (Holding stretches for at least two minutes cumulative or in a single set is necessary to elicit structural change and induce cellular adaptation. Langevin 2005)

Pro tip: Use a timer and focus on quality over quantity. Three or four well-held stretches are more beneficial than ten quick ones. Performing multiple sets of one stretch will always yield better results than a single set of many. 

3. Pay Attention to Circadian Rhythms
Flexibility can fluctuate throughout the day, often being lower in the early morning. Find times when your body feels most receptive—mid-morning or late afternoon—and schedule your stretching accordingly. 

Experiment: Try different times and note when your stretches are most effective.

4. Use constant torque sets for greater flexibility gains. 
Maintaining steady force through constant torque stretches can better reduce tissue resistance. (Constant torque sets reduce the muscle-tendon unit's resistance more effectively than constant angle stretching of the same duration. Ryan 2009 & Herda & Colleges 2011)

Real-life tip: Allocate 3-5  cumulative minutes per stretch, with at least 30 seconds at your deepest point, adjusting your joint angles as you progress throughout the sets. 

Wrapping Up

When applied thoughtfully, static passive stretching is a powerful tool for improving flexibility, aiding recovery, and promoting joint health. Remember to warm your tissues, hold stretches long enough, and listen to your body's signals.