How to Protect Your Bones as You Age – Part 2
Written by Mario Buchs, Certified Endurance Coach, Ultrarunner & Leadership Performance Practitioner
Mario Buchs is a certified endurance coach, ultrarunner and leadership performance practitioner who brings decades of experience across business, sport and human performance. He writes about resilience, leadership, mindset and what it takes to perform at your best, without losing the human in performance.
The first surprise: my bones didn't deteriorate. My baseline bone mineral density was 1.115 g/cm². By the end of the monitoring period, it was 1.141 g/cm². There were fluctuations around each individual race, but when I stepped back and looked at the bigger picture, there was no long-term decline in bone mineral density. That was important.
I had experienced two sacral stress fractures, and I was now running some of the longest and toughest races of my life. Yet my bone density wasn't progressively falling.
This didn't prove that ultra running is good for bones, nor could I claim that ultra running doesn't carry risks for bone health. But it did challenge a simple assumption. Perhaps the number of kilometres isn't the whole story.
My body composition changed too
The DEXA scans also showed some interesting short-term changes after racing. Across the three events, lean mass generally increased immediately after the race, while fat mass and body-fat percentage decreased. These changes then fluctuated as I recovered.
Visceral fat, the fat stored around the internal organs, also tended to increase immediately after the races before dropping again during recovery.
At first glance, some of these numbers might seem strange. How can lean mass go up after running 100 or 240 kilometres?
The important point is that a DEXA scan is a snapshot, not a direct measurement of muscle growth overnight. After an ultra, the body is dealing with enormous changes in hydration, glycogen, inflammation, and fluid distribution. Those factors can influence what a DEXA scan records.
So I wasn't looking at one number and declaring, "This is what happened." I was looking for patterns over time. The biggest pattern was this. My body composition fluctuated around each race, but my bone density remained broadly stable across the year.
So, was ultra running damaging my bones?
Based on my data, not necessarily. But there is an important distinction here. This was my experience, one athlete monitored over three major races. It wasn't a large clinical trial, and I couldn't isolate every variable affecting my bones.
I was also strength training regularly, and that matters. Resistance training may have contributed to maintaining my bone mineral density, so I can't claim that the results were caused by ultra running alone.
As a personal trainer, I had deliberately increased my focus on resistance training, including heavier compound movements such as squats and deadlifts.
So perhaps the better question wasn't:
"Is ultra running bad for your bones?"
Maybe it was:
"How do we support our bones while asking our bodies to do extraordinary things?"
That question changed the way I looked at ageing, running, and health. Because protecting your bones isn't simply about how many kilometres you run. It is about the whole picture, including strength, nutrition, energy availability, recovery, training load, and giving your body the right stimulus to stay strong. That lesson isn't just relevant to ultra runners. It is relevant to all of us as we get older.
Why strength training might be one of the best things you can do for your bones
As a personal trainer and running coach, I knew that simply running more wasn't going to solve my bone health problem. In fact, it could potentially make things worse if I wasn't giving my body the right support.
Our bones are living tissue. They aren't just a rigid framework holding us upright. They are constantly being broken down and rebuilt in a process called bone remodelling.
Think of it as having a construction crew and a demolition crew working on a building. Osteoblasts are the builders. They help create new bone. Osteoclasts are the demolition crew. They remove old or damaged bone.
When those two processes are in balance, we maintain healthy bone. As we age, however, that balance can change. We need to become more deliberate about giving our bones a reason to stay strong.
One of the best ways to do that is through resistance training. Running provides thousands upon thousands of repetitive impacts. That's not necessarily a bad thing. Running is a weight-bearing activity and clearly has benefits for our overall health. But lifting weights provides a different stimulus.
Squats, deadlifts, lunges, presses, and other resistance exercises place controlled loads through the skeleton. They tell the body:
"We need this structure. Keep it strong."
That's why strength training became such an important part of my own approach. I didn't stop being an ultra runner. I simply stopped believing that running should be the only thing I did to keep my body strong.
Are you eating enough to support your bones?
The other big piece of the puzzle was nutrition. As a vegan athlete, I had always considered myself a healthy eater. But being healthy doesn't automatically mean you are providing your body with everything it needs to cope with extreme training loads. Bones need nutrients. Athletes need enough energy to support the demands they place on their bodies.
My approach was to work with my nutritionist and look at my diet rather than simply assuming I was getting everything right. We increased my focus on calcium-rich foods and added calcium supplementation for three months.
For me, foods such as walnuts, figs, oranges, and dried apricots became regular parts of my diet. The bigger lesson, however, wasn't simply "eat more calcium." It was, "Don't assume that eating well and fuelling adequately are the same thing."
If you are training hard, particularly as an endurance athlete, you need to make sure you are giving your body enough energy and nutrients to recover from that training. Your body can't build and repair effectively if it is constantly being asked to perform without enough resources.
Recovery is training
My first stress fracture taught me this lesson the hard way. My second reinforced it. Recovery isn't the time between training. Recovery is part of training.
The adaptation you are looking for–stronger muscles, stronger bones, and improved fitness– happens because your body responds to the stress you place on it and then rebuilds.
If you continually add stress without allowing enough recovery, eventually something has to give. For me, that meant learning to distinguish between being fit enough to train and being healthy enough to train. They are not necessarily the same thing.
Don't ignore the warning signs
My body gave me warnings both times. The first time, I tried to work around the pain. The second time, I recognised it much sooner.
Pain that persists, changes your running mechanics, or becomes worse after exercise deserves attention. That doesn't automatically mean you have a stress fracture. It does mean you shouldn't simply assume it will disappear because you are tough enough to push through it.
Get it checked. If a specialist tells you to rest, make sure you understand exactly what rest means. Remember, I once interpreted "walking" as "going for a bushwalk." That didn't work out particularly well.
How to protect your bones as you age: My 5 rules
After two stress fractures, countless kilometres, three major ultras, and a lot of investigation, I don't think protecting your bones needs to be complicated. But it does need to be intentional.
1. Keep moving
Movement is one of the best things you can do for your health as you age. You don't need to become an ultra runner. Walk. Run. Hike. Cycle. Swim. Play with the kids or grandkids. Find something you enjoy and keep moving. The goal isn't to train like an elite athlete. The goal is to keep your body capable.
2. Lift something
If you're not currently doing resistance training, start. You don't need to start with heavy barbells. Bodyweight exercises, resistance bands, machines, dumbbells, and progressively heavier weights can all become part of a sensible strength program.
Build strength gradually and, if you're unsure where to start, get professional guidance. Your future self will thank you.
3. Fuel your body
Don't confuse being lean with being healthy. Don't assume that because your diet is "clean" or "healthy," you're automatically fuelling enough.
Pay attention to protein, calcium, vitamin D, and overall energy intake, particularly if you're exercising regularly. If you have concerns about your nutrition or bone health, speak to an appropriately qualified health professional.
4. Listen to your body
Pain is information. It doesn't always mean stop everything immediately, but persistent or unusual pain deserves attention. Don't wait until a niggle becomes an injury. Don't be afraid to ask questions.
Your physiotherapist, doctor, sports physician, dietitian, or other health professional is there to help you understand what is happening.
5. Think longevity, not just performance
This might be the biggest lesson of all. For years, I measured success by how far I could run. 100 kilometres. 100 miles. 240 kilometres. But getting older has changed my definition of performance.
I don't just want to be able to run a long way today. I want to be strong enough to keep moving for the next 20, 30, or 40 years. That means thinking beyond the next race. It means protecting the body that has to carry you there.
I still want to run long. I still want to challenge myself. But these days, performance means something more to me. It's not just about how far I can go. It's about making sure I can keep going. Because the goal isn't simply to live longer. It's to stay strong enough to enjoy the years ahead.
Read more from Mario Buchs
Mario Buchs, Certified Endurance Coach, Ultrarunner & Leadership Performance Practitioner
Mario Buchs is a certified endurance coach, ultrarunner and leadership performance practitioner whose career has spanned engineering, business, sport and human development. After more than two decades as a service engineer and business professional, working across technical, leadership, sales and training roles around the world, Mario discovered a passion for endurance sport and human performance. He has since completed 23 ultramarathons, including multiple 100-mile-plus events, and founded Healthetica Coaching and Forward Motion Leadership. Today, Mario brings the lessons of business, endurance, and life together to explore resilience, leadership, mindset, and what it really takes to unlock human potential.
