Stretch to Boost Your Metabolism and Stimulate Muscle

The past four months have been, shall we say, challenging. And disruptive. Our lives have been deeply affected – not the least of which is with respect to our access to being able to workout. As a result, viewership of online home workouts has skyrocketed, home exercise equipment sales have soared, and have you tried to buy a set of resistance bands? Virtually impossible––they’re sold out and on backorder.

This is a great time to get re-familiarized, or dare I say, re-educated with one of the most commonly neglected, often overlooked, and yet amazingly effective, accessible and necessary aspects of any fitness program: stretching. I know. Deep yawn, right? Everybody knows they should stretch, but few do. Why? Maybe because it doesn’t seem essential, or maybe the value of stretching doesn’t seem great enough. Well, I think we can change that perception!


Muscle mass is coming to be understood as a key biomarker of health and longevity. Muscle keeps us strong, keeps our metabolism revved up, gives our body shape & balance, and is a huge protein reservoir.

But what makes muscle grow, get stronger, and have more endurance? Tension. Tension on muscle is the trigger for every single adaptive change. Ever try to wrestle a week old infant into a diaper? They are surprisingly strong. But how did they get that way, just floating around in embryonic fluid for nine months? Muscle tension! Where they working out in there? In a fashion, yes! Their bones where growing and getting longer, putting constant tension on the baby’s muscles. This tension from bone elongation is the stimulus for in utero growth and strength development. No gym necessary.

Resistance training, either using exercise bands, barbells, dumbbells, machines, cables, or bodyweight, is all about tension. But so is one of the most under-rated exercise modalities: stretching. Whether it’s active stretching, passive stretching, or proprioceptive neuromuscular facilitation stretching (more on that later), tension is where the action is. Can’t get to the gym? Stretching alone can virtually halt the process of muscle atrophy.


There’s solid research data going back to the 1930s, along with thousands of accounts from elite athletes on the benefits of stretching. Stretching is a great defense to “sitting syndrome”, as it energizes us, makes us feel stronger & more confident, as well as more nimble and more mobile. Stretching:

• Increases heart rate
• Dilates muscle tissue blood vessels
• Increases cellular metabolic activity (burns calories)
• Increases protein uptake (to support recuperation, repair, and recovery)
• Increases oxygen consumption
• Increases cellular heat (as a by-product of “burning” calories for energy)
• Increases overall body circulation
• Increases range of motion
• Decreases risk of injury
• Speeds recovery
• Decreases pain and soreness
• Assists in keeping our metabolism active during weight-loss


The goal of a stretching, or flexibility program is to decrease the resting length of the muscle, thereby relaxing the resting tension so that a greater range of motion can be achieved. Proper stretching also trains the muscle to have the ability to lengthen to a greater degree, safely contributing to a greater range of motion.

In our muscles, we have specialized cells known as “muscle spindle cells”. These cells act as circuit breakers, meaning if they get stretched too much, they will fire a reflex impulse to the brain, causing that muscle to contract in order to prevent the entire muscle from being stretched too far or torn. This is purely a natural protective reflex, and is usually set too tight. The ideal  goal while stretching is to “re-educate” the muscle spindle cells to allow the muscle to lengthen and stay relaxed, rather than contract when safely stretched. Otherwise, the stretch can actually irritate the muscle spindle, or worse, stress the tendons causing micro trauma.


Not all types of stretching are created equal––typical “static” stretching is probably the most familiar, but should only be used once you are thoroughly warmed up. Otherwise, the tension can stretch connective tissue (tendons and ligaments) rather than the muscle itself. Static stretching does little to reprogram the muscle spindle.

The best result producing, most efficient type of stretching commonly used by elite level athletes is know as PNF stretching. PNF stands for “proprioceptive neuro-muscular facilitation”. That’s a mouthful, but it simply describes a way to “re-educate” the muscle spindles. Let’s say you want to stretch your hamstring. You’re sitting on the ground with your leg straight, reaching forward to touch your toes. Once you get to the point of discomfort (not pain), you hold that position, and dig your heel into the ground with medium effort for about 10 seconds. This voluntary, isometric contraction of the muscle you’re stretching takes the stress off the spindle so that it can “reset” at a new longer length. After the isometric contraction, relax the muscle without moving. Then continue to reach forward to touch your toes, and you will find that you can get an inch or so closer before the next round of discomfort kicks in. Then repeat this process again. Do this three times, with ten second holds for one set. Alternate the other hamstring side. You can start with three sets and work to five sets per muscle group.

You can stretch your quads using PNF with a partner as you lay on the ground, face down, and they push your ankle to your glute. Or you can do it alone, putting you instep in the edge of a bench, and lowering yourself down (facing away from the bench). You can stretch your pecs in doorways, rotating your torso away with your hand on the door jam at shoulder level to stretch the pec. Get creative and you can stretch just about any muscle with PNF stretching to get results quickly. That said, the more often you stretch, the more long lasting the results will be.

There are lots of stretching programs that can be found on YouTube. Search “PNF stretching techniques” and you’ll have lots to choose from. Stretching all muscles in your body––upper body, lower body, and core––will absolutely make you feel better, and perform better!

Disclaimer: This content is for informational purposes only and is not meant as medical advice, nor is it to diagnose or treat any medical condition. Please consult your physician before starting or changing your diet or exercise program. Any use of this information is at the sole discretion and responsibility of the user.