I recently had an older (former) work colleague ask me about his fitness routine. He lives in DC and walks 2 miles to work every day. He wears ankle weights, carries 8 pound dumbbells in each hand, and has a backpack full of books and papers. He's been doing that since March 2020 and has lost about 15 pounds (plus a lack of social activity that encourages eating and drinking).
"What else should I be doing to optimize my health?"
"That's an excellent question, but first of all, it's great that you are getting out and walking so much every day -- that will pay off big time with a lower resting heart rate, improved blood flow, and a higher metabolic rate," I said to him.
"But the two things I would add to your routine are weight bearing exercise and exercises that help with balance. Weight bearing exercises support bone density as you age and balance exercises will increase dexterity and help prevent falling."
He's wicked sharp and says, "OK, well what qualifies as weight bearing? What and how much do I need to lift?"
Dang, great question.
I know back squats are the best, but the hurdle for doing those are so high -- you'd need a rack, a bar, weights, a coach. Instead, I recommended goblet squats. He then asked me to demo what a squat looks like. Sure, so I dropped in to a squat in the middle of the happy hour.
This interrogative had my mind turning -- what does the science say about weight bearing exercise? what lifts are the best? how much weight is needed?
Thankfully, the National Institutes of Health recently published an study, Effects of Resistance Exercise on Bone Health. Their finding: basically any weighted resistance training is good for bone health and that low intensity cardio such as biking, swimming, and walking actually do not increase bone health (though they point out the positives outside of that).
However, when it comes to bone health, which are the best bones to stress?
According to the study, bones that are part of the hip-spine connection are the best.
They tested hip abduction/adduction, leg extensions, ankle dorsiflexion and extension, back extensions, back flies, and "abdominal exercises" (though they didn't state which ones).
They go on to state...
"compound movements of squats and deadlifts, target the major muscle groups attached to the hip and spine"
But how much weight is required for an adaptation? One study found that 5 sets of 5 at 85% of one rep max back squat led to reversal of bone density loss in elderly ladies.
You don't need to lift a thousand pounds, but probably need to squat more than the 5 pound dumbbells that came with your Peleton.
Bones will adapt to the stress you put them under. This is otherwise known as Wolff's Law. From Wikipedia: "developed by the German anatomist and surgeon Julius Wolff (1836–1902) in the 19th century, states that bone in a healthy person or animal will adapt to the loads under which it is placed. If loading on a particular bone increases, the bone will remodel itself over time to become stronger to resist that sort of loading.... The inverse is true as well: if the loading on a bone decreases, the bone will become less dense and weaker due to the lack of the stimulus required for continued remodeling."
Did you catch the important part of that though? Let me repeat --
"The inverse is true as well: if the loading on a bone decreases, the bone will become less dense and weaker."
This is very important, especially for elderly and for women.
Elderly who break hips are much more likely to die within 12-18 months due to lack of autonomy, general mobility, and depression.
Women face faster bone loss for a variety of reasons -- there is a societal expectation to NOT lift weights, there is societal pressure to eat in a way that minimizes body weight and reduces nutrients that aid in bone health, and finally menopause and late-life hormonal changes reduce bone density.
In fact, when Gwyneth Paltrow broke her leg, she found out she had Osteopenia -- which is the stage before Osteoporosis. This would make more sense for Paltrow if she were in her 50s or 60s, but she was 37 years old when it happened.
The doctors did blood work and found she was extremely deficient in Vitamin D -- a key nutrient that helps absorb calcium -- and put her on a prescription level supplement.
Unfortunately, she wasn't getting much calcium or vitamin D because her diet didn't allow for milk products. Her lifestyle and diet also called for extended fasts and "detoxes" of maple syrup, cayenne pepper, and lemon juice which basically purged her body of all nutrients, good and "bad". (NOTE: I'm not a fan of detox or prolonged fasting as a weight control regimen. HOWEVER, if you have a diet that limits dairy, meat, or whatever else, just make sure you're getting proper nutrients either through supplementation or upping foods that help make up for nutrients lost.)
On top of that, her exercise regimen included little to no resistance training -- at least not enough to elicit a skeletal response! Her training regimen consisted of light resistance bands, very light weight, and dance cardio.
All of that put together, obviously led to a bad result. And this is a major figure, of whom millions of women look up to...
HOWEVER! THERE IS HOPE!!!
A recent study found that post-menopausal women can safely do high intensity resistance training and that it will positively affect their bone mineral density and ward off osteopenia and osteoporosis.
The women in the study were 60-70 years old and had signs of less than average bone density. The women were equally divided into either a resistance training group under supervision of a coach or a low-impact home-based exercise program. The weight training group did 5 sets of 5 reps of back squat at 85% of their one rep max.
After the 8 month study concluded, here is what they found: Resistance Training led to...
Increased bone mineral density of the lumbar spine, of the femoral neck, femoral neck cortical thickness.
These are all major bone breaking points for older people.
They even found that women who weight trained were TALLER than their peers at the end of the study. Oh, and there was only one injury throughout the study, and it was in the weight training group. She missed 2 sessions and was back at it. So much for weight training being "dangerous."
Bones adapt to the stress or lack of stress you put them under.
Diet affects bone density as well.
If you are old and you break your hip, you're much more likely to die within 18 months.
Stress your bones and you won't break em as easily.