What Swimming Does To Your Bones (It’s Not What You’d Think!)

Of all the seasons, summer just might be the most bone-healthy. Many of the most delicious Foundation Foods are in season, long days of sunshine make it easy to get adequate sun exposure to produce bone-essential vitamin D, and the warm weather encourages many enjoyable forms outdoor exercise.

Today we’ll have a closer look at the effects on bone health of a classic summer activity: swimming. Whether you’re taking a dip at the beach or doing laps in the pool, swimming offers a number of benefits. But swimming’s impact on your bones might not be what you’d expect.

By examining scientific studies on the impact of swimming in relation to the physiological processes that stimulate bone growth, we’ll lay out a map for getting the most out of this popular summer pastime.

To Swim Or Not To Swim

Swimming is a great form of exercise for improving cardiovascular health and building muscle. It also has nearly zero impact on joints, which is beneficial for people with arthritis or other conditions that make it difficult to handle the impact of many land-based exercises. If you are in the habit of swimming, by all means, keep it up!

The big question about swimming and bone health centers around the effect of gravity. Due to the density of water, when you are swimming, the effects of gravity on your body are mitigated by the physical support of the water itself. When you are in the pool, you aren’t having to hold your body up against the pull of gravity the same way you do when you’re on land. That’s why swimming is low-impact.

One of the effects of gravity is the creation of weight. Have you ever tried to lift something heavy in a pool? It doesn’t seem to weigh as much! That is due to the effect of the water creating what is called hypogravity. Similarly, you’re probably aware that you would weigh less on the moon, due to the lesser gravity of that smaller planetary body, but on a more massive planet like Jupiter, you would be far heavier!

Because our bodies have the weight they do on Earth, simple physical activities such as walking and running require that them to bear their own weight. That’s why these are termed weight-bearing exercises, in addition to exercises like weight-lifting that are more obviously weight-bearing. But swimming, because water is a hypogravitional environment, is not a weight- bearing exercise.

Bearing Weight And Building Bone

As Savers know, weight bearing exercise is essential to the creation of new bone. Wolff’s Law describes the way in which the stress applied on bones by the force of our muscles holding us up against the pull of gravity stimulates bone growth.

Similar to the application of stress on muscles leading to increased muscle mass,
stress on your bones through weight-bearing exercise causes them to increase in density. Specifically, this action stimulates the synthesis of osteoblasts, which are bone-building cells.

These facts have lead many to conclude that swimming is devoid of benefits for bones, since it isn’t directly activating this process that increases bone density. However, that conclusion is premature, as it isn’t taking into consideration other factors we know about bone health.

Why Swimming Is Good For Your Bones

Even though swimming doesn’t offer the benefits that weight-bearing exercise does, it still has positive effects on bone quality. We can confidently assert that as fact-based on a comprehensive systematic review of 64 scientific studies on the impact of swimming. The name of this report states its inquiry quite clearly: “Is Bone Tissue Really Affected by Swimming? A Systematic Review.” Spoiler alert: the answer is yes.

The studies that the researchers reviewed tended to make two types of comparisons: between swimmers and people who practice high impact sports, and between swimmers and sedentary control groups. When they looked at bone density, the results were fairly consistent. Subjects who engaged in weight bearing exercises had higher bone mineral density (BMD) than swimmers, which should be of no surprise given what you just learned about how weight bearing exercises stimulates the creation of additional bone mass.¹

To further underscore this point, it was consistently found that sedentary control groups had comparable bone mass to swimmers.¹ In fact, one study from the University of New Mexico found than some elite swimmers actually had lower bone mass than subjects who didn't regularly exercise.² If you spend a significant portion of your time in the water, which creates an environment of hypogravity, your bone mass would naturally suffer. Similarly, when astronauts spend time in the microgravitational environment of space, their bone density is drastically reduced. Swimming as a regular form of exercise would not have this effect, and this review does note that swimming has no negative impact on bone density.

The reporting of these results, absent any additional information about what makes bones strong, gives a false impression. The bias towards looking exclusively at bone mineral density as a measure of bone health is arguably a result of Big Pharma’s profit-driven attempt to sell their products, which are exclusively aimed at increasing bone mineral density. The proven fact that osteoporosis drugs such as bisphosphonates actually cause fractures, is clear evidence that density is not the only measure of bone health. In fact, other measures, including tensile strength and bone matrix quality are equally important.

This is where swimming proves its merits as a part of a bone healthy exercise routine. The systematic review also found that swimmers had greater bone turnover than control subjects, which results in younger, stronger, more flexible bones that are resistant to fracture.

It’s important to note that this report does not show that swimming is better than weight-bearing exercise at stimulating bone turnover. But it does demonstrate that swimming has a positive impact on bone quality and strength. Here is the conclusion of the review, as published:

“Swimming does not seem to negatively affect bone mass, although it may not be one of the best sports to be practised in order to increase this parameter, due to the hypogravity and lack of impact characteristic of this sport. Most of the studies included in this review showed similar bone mineral density values in swimmers and sedentary controls. However, swimmers present a higher bone turnover than sedentary controls that may result in a stronger structure and consequently in a stronger bone.”¹

This result reinforces the knowledge the Save Institute has been sharing for years: osteoporosis drugs are dangerous and misguided. Bone turnover, proven here to ‘result in a stronger structure and consequently in a stronger bone,” is actually prevented by these drugs. By impeding the natural bone turnover process, osteoporosis drugs allow for the accumulation of new bone on top of brittle, old bone that ought to be removed. The result is denser, but weaker, bones.

An activity as simple and natural as swimming can do what toxic and dangerous prescription drugs cannot. But swimming alone is not enough to fully support a strong skeleton.

Swimming Builds Your Muscles

While swimming might not be adding density to your bones, it does build muscle, and increasing muscle mass leads to bone formation. That’s because muscles create additional positive stress on your bones, encouraging osteoblast formation.

Muscle strength also plays an important role in fracture prevention. Most breaks happen as a result of falls, and increasing strength and balance has been shown to prevent falls. So swimming directly contributes to the ultimate goal of treating osteoporosis: preventing fractures. Plus, swimming and other aquatic exercise are useful well into your senior years. Due to its low impact, swimming is an excellent option for people with disabilities, the very elderly, and those with joint problems.

Additionally, the cardiovascular health benefits of swimming have a positive impact on lifespan, the risk of cardiovascular disease, and endurance.³

Swimming Is A Powerful Tool

If you’re a swimmer, don’t stop! And if you’re looking for additional forms of exercise to fit into your routine, swimming is beneficial for your bones and many other systems. However, swimming alone is not enough. It’s also important to practice weight-bearing exercises that target fracture-prone body areas.

Find a workout routine that balances your swimming practice with other forms of exercise like walking, weight lifting, or a targeted bone-building exercise routine like the Densercise™ Epidensity Training System.

Densercise™ was created to provide you with the most effective targeted exercises for your bones without having to dedicate long hours to get the results you’re looking for. If you’re the sort of person who finds activities like swimming too repetitive and maybe even boring, then Densercise™ is a great option for you: it provides variety with different exercises for a full four weeks to keep things interesting, and brevity (sessions are only 15 minutes) to help you stay focused on your bone-rejuvenating goals.

Till next time,

References

¹ Alejandro Gómez-Bruton, et al. “Is Bone Tissue Really Affected by Swimming? A Systematic Review.” PLoS One. 2013; 8(8). Web: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3737199/
² Mariana Shedden, M.S and Len Kravitz, Ph.D. “Exercise and Bone Strength.” University of New Mexico. Web: https://www.unm.edu/~lkravitz/Article%20folder/exercisebone.html
³ Dr Fiona Moffatt, et al. “The health and wellbeing benefits of swimming.” Swim England’s Swimming And Health Commission. June 2017. Web: https://cdn.swimswam.com/wp-content/uploads/2017/06/1._The_Health_and_Wellbeing_Benefits_of_Swimming_June_2017.pdf