Keeping the bones strong

In a previous post, Age is just a number, I talked about a hip injury that I sustained on the tumble track at the gym. I had to go to urgent care because after an errant landing from a back tuck attempt where I got a little lost in the air. I’d liken the feeling to Simone Biles’ “twisties” in the 2021 summer Olympics, where mid-air, I completely lost my sense of where I was and how I was going to finish the skill. The main difference was (other than she being the GOAT and I was doing no twisting), Simone landed on her feet and I did not.

Instead, I landed face down, splayed out, legs going in different directions, and overextending my right hip as I crash landed. I was generally okay – there was no pop or crack sound, and I was able to stand up and walk, but I definitely hurt myself. Once I got home, as I continued to hobble around, I called a friend who is an athletic trainer who insisted I get an x-ray to rule out a broken hip.

The mention of “broken hip” rattled me. Only old and frail people break their hips; I was neither of those things. And how would I explain what happened to the urgent care doctor? In my head was the last experience at the orthopedist who I had seen for a gymnastics injury that I had sustained several years prior (busted finger from a back handspring gone awry on a new surface). When I told him how it happened, he asked me “isn’t gymnastics for teenagers?” Maybe I was feeling a little touchy about it, but I don’t need snark or judgment about my life choices when I go to the doctor, I need treatment. I didn’t go back to that particular doctor. Who needs that kind of passive aggressive negativity in their life?

When the urgent care doc came in and asked how it happened, I took a breath and dove in: So, I take gymnastics yes I am an adult and I do it anyway…I chucked a back tuck on the tumble track…my first attempt landed great..my second attempt, not so much. I was expecting a lecture about how I’m not so young anymore and I have to be careful about risky activities. Instead, she looked at me, almost impressed. Encouraged, I took out my gymnastics videos to show her that I did know what I was doing, and that this fall wasn’t my first time around the block, it was just a particularly unlucky and ill-placed one. The doc said, “well, with all of the bouncing, your bones must be super sturdy. Let’s get you that x-ray.” That was a nice change of pace. I took another deep breath, relieved that I wouldn’t feel compelled to doubt my life choices, and got some bone images taken. No break, just a sprain. Rest it, take ibuprofen, and ease back into things. 

I hadn’t really considered the bone-building benefits that all of this gymnastics training would have. I knew it was a great way to exercise, helped me maintain muscle strength and flexibility, coordination, balance, etc, but I was also taking an active part in staving off osteoporosis as well. In recent years, as I’ve moved into middle age, I’ve wanted to get a baseline bone density test, just to see if the doctor who actually supported my choice to participate in gymnastics was right, but apparently, I have to wait until I start menopause to do that. At my age, the estrogen that facilitates bone-building typically decreases, leading to osteopenia (low bone density). If I am not careful and diligent about continuing the bone-building activities, it could eventually lead to osteoporosis, where the structure of the bones deteriorate, leading to bone fragility. I am not going to be that old lady who falls and breaks a hip: I have no interest in dealing with that nonsense in 30 years. I want to climb a mountain at 80, not use a walker to get down the hall.

I remember, when I was in grad school, I took Anatomy and Kinesiology classes where we learned about bone remodeling. Old bone cells get removed by osteoclasts (that look kind of like jellyfish that suck up unused bone cells) as osteoblasts create new bone cells (osteocytes), where they harden and become new bone. Wolff’s Law states that your bones will adapt in response to the stresses you put on it. Simply put: more stress = stronger bones; less stress = weaker bones. (It’s more complex than that, but that’s the basic interpretation.) Since the muscles are attached to the bones, strengthening the muscles will naturally strengthen your bones as they pull on them in different directions. This is the heart of preventing ourselves from breaking a hip.

Another fun fact that stuck in my head from class was that when we are children, bone growth (remodeling) outpaces bone deterioration. When we hit our mid-20s, that ratio of growth levels out. At 50, there’s pretty sharp decline in the remodeling process, which gets worse as we hit menopause. At the time I learned this, I was in my late 20s, and it dawned on me: I have to really start paying attention and fight the effects of hormones, nature, genetics, and whatever else makes old people age poorly. It’s all starting to work against me now. It’s my responsibility to make sure I don’t become that little old lady with a hunchback.

I was recently clicking around to find some more information about preserving my precious bone mass and came across a scholarly article called Effects of Resistance Exercise on Bone Health (Hong and Kim, 2018). Of course, reading these kinds of articles is often like watching paint dry, and I have to read passages over and over again to make sure I’ve fully understood the medical vocabulary they use. However, this one was chock full of great information that supports my pursuit of Geriatric Gymnastics. I wanted to know more about what else I can do to support my mission of preserving my precious osteocytes.

For exercise training to elicit an osteogenic effect, the mechanical load applied to bones should exceed that encountered during daily activities. Weight-bearing impact exercise such as hopping and jumping, and/or progressive resistance exercise (RE), alone or in combination can improve the bone health in adults. Among them, RE has been highlighted as the most promising intervention to maintain or increase bone mass and density. This is because a variety of muscular loads are applied on the bone during RE, which generate stimuli and promote an osteogenic response of the bone.

Hong and Kim, 2018

Basically, in order to build bone as we age, we have to put more stress on our bones than we do in our normal routine in order to activate our osteoblasts. Low impact aerobic activities like walking or swimming, while great for so many of our body systems and necessary for cardiovascular health and general mobility, does not cut it for bone building. Resistance Exercise (RE) is required for that. According to my friends Hong and Kim, “At least two sets of one exercise for each major muscle group should be performed at a target intensity of eight to 12 repetition maximum (RM).” Modifications must be made to accommodate the individual’s tolerance, ability and level of pain, and should be done two or more days per week. In addition, the greatest benefits occur when you progressively increase the resistance over time.

They also talk about the effect of mechanical loading on bone building, as suggested by the Mechanostat theory:

This theory suggests that the bone possesses an inherent biological system to elicit bone formation in response to high mechanical strains, thereby strengthening the bone. This system involves the bone cells, mainly osteocytes, that can detect and respond to mechanical loading. Osteocytes play a key role in the remodeling process by sensing the mechanical loads, and transmitting the information to the osteoblasts and osteoclasts, which then maintain the skeletal homeostasis. 

Basically, it’s the “use it or lose it” theory. If the osteocytes don’t sense any demand, they’ll eventually get swallowed up by the looming osteoclasts waiting for a meal. An important thing to remember about mechanical loading is that it is site-specific; wherever the loading impacts are greater is where the bone building effects occur. So, doing all the squats in the world will strengthen your hips, legs and feet, but they won’t do bupkis for your upper body. You’ll need pushups, shoulder presses, pullups etc. for that.

Most people benefit from two types of resistance training: isometric (static, where the muscles don’t change length, like planks) and isotonic (dynamic, where the muscles contract and release under resistance, like push ups). We can use body weight, stretchy bands, hand weights, or machines, but we must remember to work every major muscle group, in every direction our range of motion allows. While I do use all of the above, depending on where I am and what’s accessible, my favorite place to build my bones is at gymnastics.

Using gymnastics to improve bone density

The heart of gymnastics training is the requirement that the body absorbs multi-directional forces on many different surfaces. Takeoffs and landings, hanging, pulling and pushing, inverting, balancing – all of these actions are done on surfaces of varying degrees of hardness (resistance). Progression is achieved in several ways:

• advancing a skill from a softer surface to a harder one (aka trampoline to tumble track to floor)
• moving from a higher to a lower surface, or vice versa (handspring off a tower vs. handspring on the floor)
• combining skills (roundoff + back handspring = roundoff back handspring)
• building endurance by completing more repetitions of a skill

I usually start my workout on the trampoline, which enables me to bounce on my feet, knees, hands, torso, backwards and forwards with abandon. This is where I can easily do front and back handsprings, drops on my back and belly, twist and flip with little concern about injury. Honestly, I could stay on the trampoline for an entire gym session; the impact is so much lower and my joints last a lot longer there. Because it is lower impact, it’s a great warmup and interval cardio workout, but the bone-building properties are probably not as effective, so I have to make sure I spend some time on the more challenging tasks.

From the trampoline, the tumble track awaits. It’s another bouncy surface, but much tighter and less forgiving than the big trampoline. Tumbling skills are a bit harder to perform there, so I usually resort to using momentum from a run to “punch and flip.” My repertoire on the tumble track is not as prolific, because off-center takeoffs and landings hurt my joints, but I can feel the impact of the tighter surface more as I launch myself in the air. I can usually do a few repetitions of straddle-front tucks, running punch front flips, round-offs, front and back handsprings (which are much harder on this surface). I tire out much more quickly, and I feel my joints more, but I know that the bones are absorbing more stress, contributing to the remodeling process.

The floor is the place where the elite do those crazy complex combinations from corner to corner. There, I’ve got a bunch of strength training options. Lots of handstands, cartwheels, round-offs, running punch-front tucks over obstacles, and of course, the requisite body-weight conditioning. In fact, in most gym sessions, the conditioning is done at the end of the class when your body is tired. Generally speaking, it’s so you can build muscular strength and endurance by pushing through with those tired muscles. The floor is not my favorite circuit area, because it is often the place that betrays my age the most, but there’s still plenty of things I can do.

Upper body and core strength is also achieved at the bars. I can work pullovers, pull-up prep, swinging and grip strength, which for me is my weakest ability since I don’t have a bar to hang from at home. I’m also not the size of a child, so hanging from a bar with my adult body presents a significant challenge, especially for my palms.

Between bouncing around, standing on my hands, and lifting heavy things (like when I move mats around the gym space), my plan is to stress my bones just enough to stimulate the remodeling process. Of course, even as all of this activity protects my bones, it also stresses out my joints. Invariably, I feel my back, or hip, or shoulder yelling at me for abusing it. That also happens at the beginning of the day, after I’ve gotten out of bed, before I’ve done any significant movement. I often wonder if arthritis is settling in somewhere, given all of the pounding my body endures.

My mission is to keep building my body following the mantra “work smarter, not harder” (see my thoughts on that in Chapter 3). Regardless of how my body claps back at me, I refuse to become that old biddy who can no longer stand up straight at 75. I will do the work so I can stand tall when I’m 100. I have mountains to climb and now is the time for me to make sure the body can keep up with my plans.

To read more about bone building, check out these sources:
Effects of Resistance Exercise on Bone Health
Physiology, Bone Remodeling
Osteoporosis: What You Need to Know As You Age
How Your Workout Strengthens Your Bones
The Role of Osteocytes in Inflammatory Bone Loss