Bone Health Basics For Runners: Build Them, Keep Them, Protect Them

Stamina, strength, mobility, and mindset fuel your running longevity. All of these hard-earned abilities, however, rely on their foundation’s integrity: your bones.

Stress fractures and low bone density are both major bone health issues that sideline runners. Approximately 25 percent of female runners experience stress fractures; by the age of 50, 54 percent of the U.S. adult population is diagnosed with low bone density.

Although bone health declines with age, your intentional inclusion of bone health in every decade adds up. Bone is like a retirement account. Your bone health investments accumulate until your early 30s. After that, your nutrition and exercise choices slow the rate of withdrawal.

Just as retirement account strategies change over time, bone health is not a one-size-fits-all approach; nutrition and exercise guidelines vary by lifespan stage.

Which nutrition and exercise choices are best for you? Polish your strategy by reviewing the following guidelines.

RELATED: What Women Runner’s Need to Know About Bone Health

Nutrition For Bone Health

Bone health begins with energy balance. RED-S, relative energy deficiency syndrome, compromises bone density. RED-S occurs when caloric intake is inadequate to support energy output. Weight loss, irregular periods, frequent illnesses, stress fractures, and decreasing stamina are all indicators to assess energy balance needs. Conversely, frequent excess caloric intake does not improve bone health. A higher body mass index (over 30 kg/m²) is also associated with increased stress fracture risk. When RED-S symptoms or other energy balance concerns arise, runners can find individualized solutions by consulting with a professional, such as a Registered Dietician.

Beyond energy balance, four specific minerals, vitamins, and fat sources enhance bone health:

• Calcium
• Phosphorus
• Vitamin D
• Omega-3

Calcium

Calcium is the main bone-developing mineral. According to the National Institute of Health, the recommended daily allowance (RDA) is age-specific: 

• 1,300 mg/day for 9-18-year-olds
• 1,000 mg/day for 19-50-year-olds
• 1,200 mg/day for women over 50 years old

Dairy products and fortified foods such as cereal and tofu contain large amounts of calcium to help meet daily needs. While other food sources such as spinach, sweet potatoes, and beans contain calcium, they also contain oxalic acid. Oxalic acid decreases the body’s ability to absorb calcium. Foods high in oxalic acid should not be avoided, as they offer numerous health benefits. Instead, foods high in oxalic acid should be consumed at a different time than primary calcium containing foods or supplements.

Phosphorus

Phosphorus is an often-overlooked bone-building mineral. Like calcium, the RDA is age specific:

• 1,250 mg/day for 9-18-year-olds
• 700 mg/day for 19+ year-olds

Phosphorus is highest in dairy-based foods, fatty fish, beef, and chicken. Primary vegetarian sources include nuts, potatoes, beans, legumes, and oats.

Vitamin D

Focusing only on mineral intake is not enough since the bones cannot absorb calcium without vitamin D. According to the National Institute of Health, the vitamin D recommended daily adequate intake (AI) is 500 IU for youth and adults up to age 70. This increases to 800 IU for those 70+ years old. The Endocrine Society, shares higher IU recommendations, suggesting 1,000 IU/day for adolescents and children, and 1,500-2,000 IU/day for adults. 

Since the primary natural vitamin D sources include sunlight and only a few foods (like fatty fish, beef liver, and egg yolk), most people rely on either artificially fortified foods (like dairy products, cereal, and some orange juice), or supplements. You can enhance the body’s absorption of vitamin D by pairing it with foods that contain fat, as well as foods high in potassium, magnesium, and zinc.

Vitamin D supplementation, however, requires monitoring to arrive at an individually optimal dose. Unlike the bone building minerals, vitamin D is fat soluble, meaning that the body can store it in its fat reserves. If one takes too much vitamin D on a regular basis, the accumulation could become toxic. This is why most supplement manufacturers suggest monitoring your vitamin D levels with regular blood work.

RELATED: Getting Enough Vitamin D Is More Important Than You Think

Omega-3

Omega-3 intake is emerging as a stress fracture risk-reduction factor for female runners. Omega-3 is a sub-type of polyunsaturated fatty acid traditionally associated with heart health, anti-inflammatory nutrition, and mental wellbeing. The National Institute of Health suggests an AI of:

• 1.1 g/day for most women
• 1.3 g/day if lactating
• 1.4 g/day if pregnant

Not all omega-3 sources are equal since there are three omega-3 subtypes: alpha-linoleic acid (ALA), eicosatetraenoic acid (EPA), and docosahexaenoic acid (DHA). Variety is key when obtaining all of the omega-3s from food sources.

• ALA is found in flaxseed, chia seed, and walnuts
• DHA and EPA are found in wild-raised fatty fish such as salmon, sardines, and trout
• Fortified foods such as some eggs, milk, juice, and soy products contain varying quantities of each omega-3

Like minerals and vitamins, omega-3 supplements are available for those who find obtaining the ideal amounts from food challenging. Like vitamin D, more is not always better. The U.S. Food and Drug Administration recommends an omega-3 upper limit of 5 g/day.

Exercise for Bone Health Through the Decades

Nutrition is not the only choice that impacts both health, as exercise plays a large role too. Like nutrition, exercise considerations morph throughout the lifespan.

Teens to mid-20s: Running, jumping, and obstacle course fun

Until your mid-20s, bone naturally builds faster than it breaks down, laying the foundation that lasts for decades. The American Academy of Orthopedic Surgeons recommends at least 20-30 minutes of weight-bearing exercise at least three to four days/week to optimize bone health for teens and young adults.

Even though walking is weight-bearing exercise, walking seldom provides enough load to enhance bone health at this age. Accelerating bone health requires loads to exceed that of daily activities. Resistance training increases load, but lifting weights is not the only option.

Since the brain and neuromuscular systems are not fully developed until the mid-20s, exploring movement builds more well-rounded athletic capabilities. Activities like gymnastics, jumping rope, skipping, jumping jacks, and obstacle courses of mixed weight bearing skills add both to bone health and overall athleticism.

Running is a natural bone-building exercise too. Ground reaction force, the force of the ground up through your joints with every step, also builds bone. Running typically increases lower body joint loads 4-8x body weight. While running can build bone, increasing mileage too much too fast is more likely to lead to injury. For teens and young adults, there are weekly training limits.

Experts at the Nationwide Children’s Hospital share the following guidelines for competitive young runners:

• Ages 12-14: competition distance up to 6.4 miles (10 kilometers)
• Ages 15-16: competition distance up to 13. 1 miles (half marathon)
• Age 17: competition distance up to 19.2 miles
• Age 18+: competition distance up to 26.2 miles (marathon)
• Weekly training distance should not exceed 2x the competition distance

Mid-20s to Mid-40s: Cross-training essentials

By our mid-20s, all body systems naturally decline instead of continuing to develop. Resistance training, however, is the language of reversibility. Weight training may be able to counteract initial age-related bone loss and even increase bone density by an additional one to two percent. Such cross-training also reverses sarcopenia, the natural age-related loss of muscle fibers. Preserving muscle fibers protects bones becasuse muscles can help distribute ground impact forces.

Resistance training for bone health requires inclusion of heavy loads (at least 80 percent 1RM), and multiple training angles. 80 percent of 1 RM (one-rep-max) is the weight that you can lift with good form for 8 reps, but not more. Bone builds according to Wolff’s law, which requires not just enough load, but also load across multiple angles.

You can implement these bone health builders in your own resistance training plan:

• For each workout, select 6-8 exercises (including major upper body, lower body, and core movements).
• Select a load that allows you to perform 3-4 sets of 8 repetitions per exercise; the last 2 reps should be challenging.
• Allow 60-90 seconds between each set so you can maintain both load and technique.
• Each week, include a new angle. For example, if you perform a back squat in week 1, try a front squat in week 2, try a sumo squat in week 3, try a conventional deadlift in week 4.

Like younger women, running impact forces can also enhance bone health.  For pre-menopausal women with regular menstrual cycles, accumulating at least three hours/week of running on a regular basis increases bone mineral density.

At some point in the mid-20s to mid-40s many women also begin to explore yoga, stretching, and mobility training. Mobility naturally declines with age, but dedicated mobility work can preserve available joint range of motion. Since bones can only be strengthened in available joint ranges of motion, dedicated mobility work offers greater bone-strengthening opportunities. Yoga and stretching may offer additional bone-building benefits through their contribution to stress management. Stress management decreases cortisol. Elevated cortisol limits bone cell building capabilities, which decreases bone density. 

Mid-40s to Mid-60s: Scalability

At some point between the mid-40s and mid-60s most women enter menopause. Menopause includes a remarkable decrease in estrogen, which accelerates bone loss. Most women lose more than 50% of their peak bone mass during their adult years, with half of this loss occurring in the first 10 years of menopause.

Remarkable hormonal shifts also change the body’s nutrient absorption, sleep patterns, and recovery time. Instead of continuing to push through fatigue, peri-menopausal and menopausal women experience greater bone and overall health by increasing training intensity variability. Such variations  allow for more active recovery days with slower runs, lighter weights, or increased mobility work.

Sarcopenia (natural age-related muscle loss) also accelerates. Fast-twitch muscle fibers are affected more than slow-twitch muscle fibers. This shift means that women cannot rely as much on speed for running and weight lifting as much as when they were younger. The slower speed does not negate the positive bone-building effects from weight lifting and running, but women in their 40s-60s may need to scale speed work and weight lifting to preserve technique.

65+: Smarter, not harder

With 40 percent of post-menopausal women experiencing fractures, and all body systems naturally declining, older women must train with a smarter strategy instead of simply pushing themselves harder.

The Centers for Disease Control (CDC) suggests at least 150 minutes per week of moderate-intensity activity such as brisk walking, or 75 minutes per week of vigorous activity like running. Instead of performing all of the activity on 1-2 days/week, consistency spread over several days to accumulate recommended minutes offers greater health benefits while reducing injury risk.

Like younger adults, bone health requires external load in excess of normal daily loads. Instead of running more, mature women can build bone health through cardiovascular activity by walking with light wrist or ankle weights, or walking uphill. When incorporating new exercises, benefits only outweigh risks by starting slow. For example, start by carrying 2 water bottles for a couple of minutes as you take a warm up lap around your neighborhood or the local track. Just like running progressions, gradually adding a few minutes each week is much safer for bone, as opposed to new exercise techniques all at one time.

In addition to cardiovascular activities, older women should strength train at least 2 days/week. When resistance training, bones still need at least 80 percent of the 1 RM to promote bone health. While the absolute number of pounds lifted is likely lower than in previous life decades, women can still scale the load to what can be achieved in 8 reps for 3-4 sets with good technique.

Keep Your Balance: Practice, Practice, Practice

Older women also need to include specific-balance training to help decrease fall risks. Balance training, however, does not mean standing on a BOSU or wobble board. Balance stems from 3 major inputs: vision, inner ear, and sensation from the feet. All three need training. Such training might look like this:

Vision

Train with 1 x 10 pencil push-ups daily. Perform a pencil push up by holding a pencil arm’s length away from your nose. Keep your eyes focused on the pencil as you bring the pencil toward your nose. Once the pencil touches your nose, keep your eyes focused on the pencil as you return to the start position. Instead of training the exact same angle for all 10 reps, try varying the pencil position as you reach away from your body to include multiple angles.

Inner ear

Inner ear balance varies based on head position. Try standing with your feet together while performing 1 x 5 for each of the following head movement exercises each day:

1. Look up and down
2. Look side to side
3. Tilt your head from side to side

If standing with feet together is easy, work through the following progressions over time as you complete the moving head exercises:

1. Stand with one foot in front of the other
2. Stand on one foot
3. Stand with feet together with eyes closed
4. Stand with one foot in front of the other with eyes closed
5. Stand on one foot with eyes closed

Sensation

Changing surfaces trains the feet’s balance input. Sensation can be trained at the same time as the inner ear by changing the standing surface. Start by wearing socks or standing in bare feet for each inner ear exercise. If this is easy, work through the following progressions while performing the head movement exercises:

1. Stand on a folded bath towel
2. Stand on a 2-inch-thick balance foam
3. Stand on a balance disc or BOSU

All balance exercises should prioritize safety over speed of progression.

More Bone Health Considerations

While maximizing bone health with a lifespan nutrition and exercise plan sets the foundation for running longevity, lifestyle does not guarantee the same bone health outcome for every woman.

Bone health emerges from a  complex interplay of nutrition, exercise, and many influences outside of our control, including: genetics, gender, age, individual bone structure, hormonal imbalances, and medical conditions.

Many women will receive an osteopenia (low bone density) or osteoporosis (very low bone density) diagnosis at some point. Such a diagnosis does not necessarily represent the end of  running, and such a diagnosis rarely requires retiring from an active lifestyle. Osteopenia and osteoporosis typically do not affect all bones equally. After a bone scan, women should ask their doctors which bones are affected and if there is any activity that they need to avoid or modify.

For women diagnosed with spine osteoporosis, there are a few special training precautions:

1. Avoid repeated spine flexion. The most common examples are crunch and sit-up variations. Women can still continue core work by replacing crunches and sit-ups with planks, dead bugs, and Pallof presses.
2. Avoid repeated loaded spine rotation. Instead of performing torso rotations, focus on cross training with anti-rotation exercises such as single-arm rows or singl- arm chest presses.
3. Avoid combined spine rotation and flexion. Instead of the classic windmill dynamic movement, preserve bone and joint health performing CARS (controlled articular rotation) exercises for the hips and shoulders.

Next steps

Before you leave this article, bookmark it, share it, or save it somewhere so you can reference lifespan bone health recommendations not only today, but throughout your journey for decades to come.

Then, enhance your bone health today by completing this sentence: “I will enhance my bone health by _______________ .” Fill in the blank with an action step from what you have just learned.

Dr. Meredith Butulis, DPT, PT, CSCS is a licensed sport and orthopedic physical therapist, certified exercise physiologist, strength and conditioning coach, personal trainer and yoga/Pilates instructor practicing since 1998. She is the creator of the ISSA Fitness Comeback Coaching Certification, author of the Mobility | Stability Equation Series & Stop Joint Wear and Tear books, and host of The Fitness Comeback Coaching podcast.

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