A Study Of 251 Adults Just Revealed An Unexpected Window Into Bone Health
If you've ever skipped leg day, new research1 gives you a compelling reason to reconsider, and it has nothing to do with aesthetics.
A study published in Medicine & Science in Sports & Exercise found that lower-body strength is one of the strongest, most consistent predictors of hip bone density across the entire adult lifespan, from age 18 all the way to 85.
That's a pretty wide net, and the implications reach further than most people expect.
About the study
We've known for a while that both muscle strength and bone density tend to decline with age.
What's been less clear is how closely those two things are connected, and whether that relationship looks different depending on how old you are or whether you're male or female. This study set out to map that.
Researchers recruited 251 adults (149 women and 102 men) ranging in age from 18 to 85. To measure strength, participants completed a one-rep max leg press: the heaviest weight they could push with their legs just once.
Bone density was measured at the hip and lower spine using dual-energy x-ray absorptiometry (DXA), a widely used imaging scan.
Leg strength predicts hip bone density at every age
Leg-press strength was strongly linked to hip bone density, and that connection held up even after accounting for age, sex, and body fat.
It wasn't simply that heavier people had denser bones; leg strength itself was independently tied to hip bone density, regardless of what someone weighed or how much body fat they carried.
The relationship was stronger in younger adults than in older ones, which makes a strong case for building lower-body strength early in life, not just later.
Why this matters at every age
One of the most notable things about this study is its age range. The link between leg strength and hip bone density showed up consistently across all participants, from 18 to 85.
Bone health is often treated as something to worry about later in life, but this data tells a different story: the habits you build in your 20s, 30s, and 40s are shaping your skeletal health for decades to come.
The women's angle
The study also uncovered an important difference between men and women, specifically when it came to the spine.
Age-related declines in spinal bone density were evident in women but not in men, a pattern that reflects the well-documented impact of hormonal shifts around perimenopause and menopause on bone loss.
Spinal bone density measurements in older men should be interpreted with caution, as they may be less reliable as a health marker in that group.
For women especially, building and maintaining lower-body strength isn't just a fitness goal; it's a proactive way to protect your skeleton during a period when it's most vulnerable.
How strength training supports bone health
When your muscles contract hard (like they do during a squat, a leg press, or a deadlift) they pull on the bones they're attached to. Bones respond to that demand by reinforcing themselves, getting denser and more resilient over time.
The more load you place on your body through strength training, the stronger your bones become in response.
This is why the connection between leg strength and bone density is so direct. The hip responds particularly well to the forces generated by lower-body strength training, which lines up with why the study found its strongest associations there.
Research on bone health and jumping suggests that impact-based exercise can also play a supporting role.
Lower-body moves that build the hip strength your bones need
You don't need to be a competitive powerlifter to benefit. The key principle is progressive overload, gradually increasing the challenge to your muscles over time so your bones continue to receive the signal to stay strong.
Exercises that tend to be most effective for hip bone density include:
- Squats and goblet squats: Load the hips and thighs through a full range of motion
- Leg press: The exact movement used in the study, accessible for all fitness levels
- Romanian deadlifts: Target the back of the legs and glutes
- Lunges and split squats: Add a single-leg challenge and improve balance
- Step-ups: A functional, lower-impact option that still loads the hip effectively
Lifting heavier weights for fewer reps tends to be more effective for bone density than lighter weights for high reps. Most research on resistance training for bone health points to two to three sessions per week as a meaningful target.
Consistency matters more than any single workout; a sustainable routine you can maintain for months and years will do far more for your bones than an intense program you abandon after six weeks.
The takeaway
Leg strength may serve as one of the clearest windows into your skeletal health, with stronger lower bodies linked to denser hip bones whether you're 25 or 75.
For women navigating perimenopause or beyond, the case for prioritizing lower-body strength training is especially compelling given the accelerated bone loss that can come with hormonal changes.
It's never too early, or too late, to make leg day a non-negotiable.