We all know that exercise is essential to good health. Exercise can improve the health and fitness of the heart and lungs, sleep quality, energy levels, and even mental wellbeing. However, exercise is also extremely vital to the health of your bones and one's skeletal health and integrity. Much like muscles, bones are dynamic tissues that respond to exercise by bolstering their resilience and becoming stronger. People who exercise regularly and consistently have stronger bones and a much higher bone density than those who do not exercise and have been sedentary. This reduces the risk of developing osteoporosis.
Age-related bone deterioration is a significant health concern facing adults. Historically, high-impact and weight-loading exercises has been linked to bone turnover. However, these types of activities are not always appropriate for middle-aged and older adults due to pre-existing injuries, physical decline, chronic disorders, or arthritic conditions such as osteoarthritis. Water-based exercise is proving to be effective for bone regeneration, has lower risks of traumatic fracture, and applies less stress to joints. It also comes with fewer risks and additional health benefits while being more achievable for older adults and those with limited mobility.
To understand why exercise is essential for bone health, it helps to understand how bones work. Bones are constantly changing. This process is called 'remodelling'. Bone cells known as osteoblasts, build new bone. Meanwhile, other bone cells (osteoclasts) break down and remove the old bone. This bone change is controlled by things like vitamin D and hormones, including; calcitonin, parathyroid hormone, oestrogen (women), and testosterone (men).
From birth to approx 25, you build more bone than you lose, and grow significantly during these years. Your bones are not only getting bigger as you grow, but they are also developing in density. This determines how strong the bones will be.
From approx 25 to 50, bones break down and rebuild at about the same rate, and you do not grow significantly. This is when you've achieved what is known as your 'peak bone mass .'Bones are at their strongest during this period.
After approx 50, more bone breaks down than you can rebuild. Everyone experiences some bone loss as they age, but that does not mean they will develop osteoporosis. It is more common for Women to experience rapid bone loss post-menopause due to a sharp drop in oestrogen levels. It's estimated that women lose up to 10% of their bone mass in the first five years after menopause.
For healthy bones, exercise is vital for everyone – men and women from the very young to the very old.
Swimmers typically show lower bone mineral density compared to other modalities. This data has questioned the ability of aquatic activities to improve or even maintain bone health. However, on the other hand, despite a reduction in gravitational forces, water-based training programs have proven to be hugely beneficial in the prevention and/or treatment of osteoporosis.
A study by Ay and Yurtkuran reported an anabolic effect of aquatic exercises on the bones of postmenopausal women. This was evidenced by increased hormonal markers (insulin-like growth factor-1, growth hormone, and calcitonin).
Another study evaluated a high-intensity aquatic exercise program on bone remodeling markers and bone mass in a group of postmenopausal women. 108 were randomised into an aquatic exercise group and a sedentary control group and performed 24 weeks of aquatic exercises. Bone mass was measured by a Bone Density Scan (DEXA) both before and after the underwater intervention. The study found that the aquatic fitness regimen effectively reduced bone resorption and boosted bone formation, thus averting a decrease in femoral trochanter bone mineral density among the participants in the aquatic exercise group.
Finally, postmenopausal women trained for three one-hour sessions per week for seven months and were compared with an aged-matched control, non-exercise group. A DEXA scan quantified the bone mineral content, density, and the associated z and t-scores. The control group demonstrated a decline in all measures, but the aquatic exercise group increased bone mineral content while maintaining bone mineral density. The study found that aquatic exercise can effectively preserve bone mineral density, mitigating the anticipated annual decrease.
The results of these three research studies substantiate that planning and executing an aquatic exercise program that positively affects bone status is possible. These studies focused on postmenopausal women as this demographic experiences the most considerable risk of bone health loss. The aquatic learnings can be applied across all populations to facilitate bone health throughout one's lifetime.
Developing osteogenic potential through specific muscle strength training in the aquatic environment is possible. The answer lies in how the water is used, the level of resistance of the water, and the water equipment used. Swimmers shift themselves through the water as quickly and efficiently as possible with as little water resistance in the pool as possible. Aqua Aerobics, specific exercises in water, use some water resistance in their movement. The harder you push or pull through water the more resistance you experience. Higher intensity and specialist water resistance programs like Water Resist use larger resistance levels. Water offers natural resistance that can be increased with speed, shaping and movement including increasing the surface area and applying different directional forces which can help strengthen the muscles and regenerate bones.
Equipment can also be leveraged to increase resistance and load to regenerate bones. Hydrorider Resistance Bands are extremely beneficial for adding limb loading to address age-related bone loss. They add load to limbs and can be programmed with repetitions to the point of failure, which research indicates has a more significant effect on countering age-related bone loss than heavy weights. A Hydrorider AquaBike can also be highly beneficial for high levels of lower limb resistance and we have seen great results post limb fracture and in increasing leg strength and bone regeneration.
The efficacy of exercise in preserving bone health hinges on both program design and performance regularity. Not all exercise professionals are familiar with Water Resistance. Before embarking on an exercise regimen, consultation with a water specialist like Water Resist is strongly advised.
It is worth noting that balance and flexibility exercises can reduce your risk of falling and bone injury. This is important for preventing fractures. Prevention is always better than needing a cure. See the Balance and Fall Prevention blog article for further information on aquatic programs for balance and flexibility.