Bone density might not be the first thing you think about when you hit the gym, but it’s one of the most important markers of long-term health. It plays a major role in how strong your bones are, and how well they can resist fractures as you age. According to research, bone density peaks around age 30 for women, and starts to decline after menopause—up to 20% in the five to seven years after menopause.
“Bone density is an important indicator of how likely bones are to break,” Susan Bukata, MD, professor and chair of orthopedics at UC San Diego Health, and advisor for Solaria Bio, tells SELF. “When you have osteoporosis, your bones become brittle and porous, making them more likely to fracture from minor falls.” Bone density is only half of the equation, because bone quality also declines overtime, Dr. Bukata explains. “We become more dependent upon bone density to maintain the strength of our bones.”
That shift is exactly why your workout routine matters more than you might think.
How exercise builds stronger bones
Bones are living tissue, constantly responding to the stress we place on them. “Exercise provides regular ‘stress’ to the bones and stimulates those cells to respond,” Dr. Bukata explains. “Those cells then put out signals to your body to make more bone in areas of stress, to strengthen the bone, and to repair bones if there are areas of micro-damage.”
In other words, movement isn’t just maintenance—it’s a signal for your bones to rebuild.
That’s especially true when it comes to impact and resistance. “Bone and cartilage are a use-it-or-lose-it situation,” Jojo Kelly, CPT, and head coach at Tone House, tells SELF. “Contrary to what many people believe, running and jumping actually promote healthy bones and cartilage.” That checks off cardio.
The most recent Physical Activity Guidelines for Americans recommend at least 150 minutes of moderate-intensity cardio or 75 minutes of vigorous-intensity cardio (you can also do a combo of the two) each week for general health benefits.
“The other way we want to stimulate bone growth is through resistance-training,” Kelly says. “During a lift, the muscle connected to its tendon pulls on where it attaches to the bone causing the bone to react and remodel.”
The key elements of a bone-building routine
To support bone density, your routine should include two pillars: weight-bearing (impact) activity and strength training. Dr. Bukata recommends aiming for at least 30 minutes of weight-bearing movement each day—walking, running, dancing, or even climbing stairs all count. “The key is to get up on your feet and move for those 30 minutes,” she says, noting that consistency matters more than doing it all at once.
