By Mara Abbott,
Olympian and CTS Contributing Editor
Of course it would happen at bedtime. My contacts out, PJs already on, I found myself urgently drawn to the computer. I needed, immediately, right then, to research ways to strengthen my bones. I don’t recommend this nocturnal hobby – after all, it was deep into one of those fitful nights that I discovered several studies linking chronic sleep deprivation and an increased risk of osteoporosis. The morning-afters also made me groggy, which was unfortunate because it seems caffeine isn’t a great bone booster either.
In a recent post I wrote about the positive effects weight training has had on my bone density. Cognitively, I knew it was supposed to and that the added impact of regular running would further help a skeleton that had previously traveled the earth on cushy tubes of inflated air. However, I had to wait a full year to get a follow-up DEXA scan, and running and lifting just didn’t feel like enough. I had upgraded the ways my energy outputs benefited my bones, but what about my inputs? Could I make improvements with nutrition?
How do we make bones?
For any of my research to make sense, I had to learn how bones work. Turns out, it’s complicated. There are still a lot of unanswered questions. I should be clear – I can’t offer you advice on what to do to protect your individual bones. That’s a matter for a medical professional with access to your unique health history. I can tell you what I learned that may help you be a more informed advocate for your own health.
Bones are dynamic. Think of it like hair – strands fall out, strands grow in, and in an ideal world this balances. If it doesn’t, you get a bald spot. Our nervous systems and muscles need calcium to function. When the parathyroid glands sense that there is too little calcium in the bloodstream, they signal white blood cells called osteoclasts to liberate a bit from storage – that is, to take it from bones. Similarly-named-don’t-get-confused osteoblasts then lay down fresh bone matrix materials and redeposit minerals. This destruction-recreation happens all the time. It’s supposed to.
What strengthens bones?
Our body responds to stresses, be they muscular, cardiovascular or skeletal, by attempting to get stronger. When the body senses an increased stress to a bone – perhaps from running, jumping, or picking up heavy objects – the osteoblasts get to work. With proper recovery, bones will grow denser and stronger in the areas that have been stressed. When stress to bones outstrips the body’s ability to rebuild, you end up with stress fractures. They hurt.
The importance of regular impact to bone density means low-impact athletes like cyclists and swimmers have cause for concern. Our muscles atrophy if we sit on the couch all day, and gliding about on bicycles doesn’t do much for our bones. One 2009 study found that competitive cyclists were three times more likely than their non-cyclist peers to have low bone density. Don’t panic – but do be diligent. According to a randomized trial of premenopausal women, even a bit of regular jumping up and down can help. In between hops, make sure you eat right.
Nutritional support for bones
Calcium and Vitamin D
In order for the osteoblasts to deposit calcium in your bones, you need to consume it in your diet. Calcium can be found in the traditional dairy products as well in sardines, beans and leafy greens. Do be aware that some greens – spinach in particular – tend to hold onto their calcium, so you won’t be able to absorb it as readily. Vitamin D is required for your body to actually absorb that Calcium. Though it’s true that we can get vitamin D by simply spending time outdoors in the sun, if you’re a smart sunscreen wearer you unfortunately might miss that benefit. Talk to your doctor to see if supplementing additional vitamin D makes sense for you.
When I crashed and broke my collarbone, my coach Dean Golich reminded me to pay attention to my protein intake while I was recovering. I figured this advice was an automatic tic, like a mother reminding a child to look both ways before crossing the street. However, it turns out that over half of the material in your bone matrix is made of protein. As usual, Dean knew what he was talking about. This doesn’t mean overloading on protein will enable you do build super-bones. It does mean that chronically shortchanging your protein intake could inhibit your ability to rebuild as necessary.
This is the most important point. Regardless of your caloric intake, your body is always breaking down bone to send calcium where it is needed. However, with insufficient energy intake, it must choose how to allocate scarce calories. Your bones are a long-term project and they get overlooked in times of immediate scarcity, kind of like infrastructure in times of budget deficits. Over time this becomes a big problem, but not necessarily one that is readily apparent as it’s developing. An under-fueled or overtrained runner with multiple stress fractures will raise a red flag. Cyclist fractures are generally blamed on 50kph ground forces, and low bone density can compound undetected for decades.
Consider this – as you push through your next big day of training, that sweat soaking your jersey contains calcium. To replace it, your osteoclasts are going to break down your bones. Recent research showed that pre-loading rides with calcium supplements could potentially diminish that effect. It might also be worth looking into whether your sports drink provides you with calcium – some newer ones do. However, even with additional calcium, if you aren’t fueling while you ride your body won’t have the energy to prioritize laying down new bone matrix. Now imagine the effect of a negative calcium balance day after day after day.
Dean closed nearly every conversation of our ten-year coaching relationship by asking, “How are your habits?” Despite the charming commercials, even if you drink it every morning of your life, milk alone won’t build strong bones. Long-term dedication to a whole bunch of good habits? That just might.