Summary of Huberman Lab Podcast Episode: Enhance Flexibility: Research-Backed Stretching Protocols | Huberman Lab
Podcast: Huberman Lab
7 min. read
— Description —
Discover the two main mechanisms of flexibility and how age-related declines can be offset with a consistent stretching practice Improve your range of motion, posture, and reduce pain with a dedicated range of motion practice Learn the best stretching protocol and techniques to achieve the greatest gains in limb range of motion.
Enhance Flexibility: Research-Backed Stretching Protocols | Huberman Lab
Table of contents
Key Takeaways
- Two main mechanisms of flexibility: (1) the first senses when stretch is too much and signals muscle contraction back into place; (2) the second senses excessive load and shut down the ability to contract muscles for safety
- Without intervention, age-related declines in the range of motion (average of 1% per year) are inevitable unless you deliberately work on it
- A consistent stretching practice can improve range of motion and offset the age-related decline
- A dedicated range of motion practice increases flexibility and also improves posture, reduces pain, improves gait, etc.
- Superset exercises of antagonistic muscle groups (e.g., push/pull) will offset muscle fatigue as compared to straight sets (completing all sets of push-ups before moving on to pull-ups)
- All forms of stretching (dynamic, ballistic, static, PNF) will improve limb range of motion but static stretching post-training session or calisthenics gives the greatest gains
- Stretching protocol: 2-4 sets of 30-second hold static stretches totaling 5 minutes, 5 days per week
- Ballistic and dynamic stretches are useful for improving performance but won’t necessarily increase limb range of motion as much as static stretching
Introduction
- Dr. Andrew Huberman, Ph.D. is a Professor of Neurobiology and Ophthalmology at Stanford University School of Medicine. His lab focuses on neural regeneration, neuroplasticity, and brain states such as stress, focus, fear, and optimal performance.
- In this episode, Andrew Huberman explains the science behind a range of motion and flexibility and how to increase them by using science-supported protocols.
- Host: Andrew Huberman (@hubermanlab)
Basic Physiology Of Flexibility
- Flexibility involves neural (nervous system), muscle, and connective tissue working together
- The nervous system controls muscles via motor neurons which control the contraction of muscles
- Muscles (temporarily) shorten when contracted and (temporarily) lengthen when relaxed
- Muscle spindles wrap around muscle fibers and send information from muscle back to the spinal cord
- If a muscle is stretched, the muscle spindle will spend information to motor neurons and cause the muscle to contract to avoid overstretching and bring the range of motion into a “safe” zone
- Mechanism 1 – Stretch via motor and sensory neurons: motor neurons contract muscles, spindles sense stretch within a muscle, and sensory neurons send signals to motor neurons to contract and bring the body back within a safe range of motion
- Golgi tendon organs (GTOs) sense how much load is on a given muscle and have the ability to shut down motor neurons and accompanying muscle contraction
- GTOs make it impossible for muscles to contract
- Mechanism 2 – Load via GTOs: when muscles are overloaded, GTOs will send a signal to shut down motor neurons and prevent muscle contraction to allow muscles to stretch and return to safety
- Stretching consistently over time will change muscles
- When we stretch, muscles aren’t literally getting “longer” – the myosin and actin conformation is changed
- The length of muscle belly and location of insertions relative to connective tissue and limbs is genetically determined
Neurological Components Of Flexibility
- Interoception: the ability to sense what’s happening in our own body
- Exteroception: the ability to sense things in the environment around us
- The Insula region of the brain is responsible for processing and making sense of the external and internal world
- Posterior insula: houses a dense collection of neurons (von Economo neurons) concerned with somatic experience, how movement makes us feel, whether to override pain and discomfort and lean in or avoid the movement
- Von Economo neurons: connected to brain areas that can shift state internal state from sympathetic activation (alert, stress) to parasympathetic activation (rest)
- Von Economo neurons allow the brain to override spindle mechanisms and subtly override reflexes that would cause us to contract
- Von Economo neurons pay attention to what’s happening in the brain and body as well as control the amount of calmness or alertness in response to stimulus
- Experiment: while standing, try to touch toes and see how far you get, then; try again, this time contracting quadriceps muscles – you should reach farther because these muscles are antagonistic (this is thanks to GTOs)
- If a muscle is tight, you can leverage muscle anatomy by contracting antagonistic muscle – e.g., for tight quadriceps, contract hamstrings; for tight hamstrings, contract quadriceps
Methods Of Stretching
- Types of stretching: dynamic, ballistic, static, proprioceptive neuromuscular facilitation (PNF)
- Dynamic & ballistic stretching involves momentum, as opposed to static stretching where positions are being held for a given time
- Dynamic stretching: less use of momentum towards the end range of motion
- Ballistic stretching: swinging of limbs through a full range of motion
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Static stretching: holding stretch through end range of motion
- Active static stretching: dedicated effort to put force behind stretch to extend the range of motion
- Passive static stretching: relaxing into the furthest range of motion
- Proprioception involves knowledge and understanding of where our limbs are in space and relative to our body
- PNF example: leverages proprioceptive system – for example, using a strap while laying on back to stretch hamstring then trying the same stretch without the strap
- To increase limb range of motion, stick to static and PNF stretches
- Ballistic and dynamic stretches are useful for improving performance but won’t necessarily increase limb range of motion as much as static stretching
Stretching Dos And Don’ts
- Change in flexibility is dependent on frequency and duration
- Hold static stretches for 30 seconds to increase limb range of motion over time – more than 30 seconds is not additionally useful according to the research
- Perform static stretches at least 5 minutes per week per muscle, distributed throughout 5 sessions per week to maintain or improve range of motion over time
- Improvements in range of motion will take place around 3 weeks
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Protocol: 2-4 sets of 30-second hold static stretches, 5 days per week
- Sample protocol: 3 sets of 30-second static stretching for hamstrings x 5 times per week
- Rest between stretching sets is not as critical as during strength or resistance training, try 1:1 or 1:2
- It’s best to perform static stretches once core body temperature is elevated (i.e., post-workout or calisthenics)
- Static stretching can limit performance if done before cardio or strength training workout
- Key elements of stretching protocol: (1) feel the muscles as you stretch & stretch to the end of a range of motion at that moment (it will vary); (2) low intensity (non-painful/straining) static stretching is at least as effective as more intense stretches (pushing to pain)
- While static stretching is best reserved for the end of the workout, it does have a place prior to exercise if it will help your body overcome limitations and put your body in a greater position of safety
Potential Benefits Of Stretching For Illness
- Stretching induces relaxation at a local and systemic level
- Tumor volume in cancerous mice was 52% smaller in mice in one-month stretch protocol versus control – unlikely due to stretch alone but maybe relaxation allows the nervous system to combat tumor growth more effectively
- Pain tolerance of yoga practitioners is at least twice as high as non-yoga practitioners – likely related to increased volume of the region of the brain responsible for interoception
Sources
- Force enhancement after stretch of isolated myofibrils is increased by sarcomere length non-uniformities (Scientific Reports)
- Microfluidic perfusion shows intersarcomere dynamics within single skeletal muscle myofibrils (Biophysics and Computational Biology)
- The Effect of Time and Frequency of Static Stretching on Flexibility of the Hamstring Muscles (Physical Therapy & Rehabilitation Journal)
- The Relation Between Stretching Typology and Stretching Duration: The Effects on Range of Motion (International Journal of Sports Medicine)
- A Comparison of Two Stretching Modalities on Lower-Limb Range of Motion Measurements in Recreational Dancers (Journal of Strength and Conditioning Research)
- Stretching Reduces Tumor Growth in a Mouse Breast Cancer Model (Scientific Reports)
- Insular Cortex Mediates Increased Pain Tolerance in Yoga Practitioners (Cerebral Cortex)