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Adaptation of bone to exercise

Danny O'Dell explains how exercise is beneficial to bone development.

Bone is considered a connective tissue that when stressed, deforms as a result of the load. To meet the strain imposed upon the external structure caused by the bending, compressive, torsional loads and the muscular contractions at the tendinous insertion points, osteoblasts migrate to the surface of the bone.

At the point of the strain, immediate modelling of the bone begins. Proteins form a matrix between the bone cells. This causes the bone to become denser due to the calcification process occurring during the growth response to the load.

The new growth occurs on the outside of the bone to allow the manufacture of new cells to continue in the limited space within the bone itself. This outer layer is commonly known as the periosteum.

Adaptations take place at different rates in the axial skeleton (skull/cranium, vertebral column, ribs, and sternum) and the appendicular skeleton (shoulder, hips, pelvis and the long bones of the upper and lower body - essentially the arms and legs). This is due to the differences in the bone types - trabecular (spongy) and cortical (compact) bone.

The stimulus for new bone formations

Minimal essential strain (MES) refers to the threshold amount of stress applied to the structure which is necessary to elicit the growth of new bone material. A force exceeding MES is required to signal the osteoblasts to move toward the periosteum and begin this transformation. MES is thought to be 1/10 of the braking force needed to fracture the bone. Training effects have a positive relationship with bone density, just as sedentary living habits play a role in the loss of bone density.

Training to increase bone formation

Programs designed to stimulate bone growth, also known as bone mineral density (BMS), will incorporate the following characteristics:

  • Specificity of loading
  • Proper exercise selection
  • Progressive overload
  • Variation

Specificity of loading

This will see the exercise patterns emphasizing specific areas in need of assistance. New or unusual forces in varying angles of stress will enable your bones to adapt to the greater intensities. Military presses, bench presses, upright shoulder shrugs, push-ups, chin-ups, plus other similar exercises would help develop stronger upper body bones. Lower body exercises selections would be along the lines of these types of movement patterns: squats, calf raises, deadlifts, and straight leg deadlifts.

Exercise selection

This will promote osteogenic stimuli (factors that stimulate new bone formation) and will exhibit these characteristics: Compound exercise muscle movements consisting of multijoint, structural loading and varying force vectors. Such exercises are the squat, deadlift, military press and bench press along with the Olympic style moves.

Progressive overload

Greater than normal loads force the body to adapt positively regarding new bone formation. This response is greater if the load changes are dramatic and repetitive. Younger bones may be more receptive to osteogenic changes in the load variance than older bones.

Variations of exercise selections

The body adapts quickly to imposed loads per the Specific Adaptation to Imposed Demands (SAID) principle. To prevent accommodation, the exercises need to be varied periodically. There are many individual differences in the same exercise, e.g. the squat has at least seventy variations, and these do not include any machine versions.

The mechanical load consists of the following:

  • The magnitude of force - Magnitude of the load density or the intensity of the load will generally be above eighty to ninety per cent of repetition maximum (RM) to see improvements in the tissue response.
  • The speed of force development - The rate or speed of loading means how fast the force is being applied to move the load in a concentric muscle contraction (force applied against a weight with the muscles shortening). Think speed during the lift.
  • The direction of forces -Varying the direction and pattern of movement will stress the bone and the attaching musculature. Full range of motion in all exercises ensures to a certain extent that the forces are applied as required.
  • The volume of force applied - The first three mentioned above are primarily responsible for bone mineral improvements. Typically, the repetitions do not need to exceed thirty to thirty-five to see improvements when the load is within the correct intensity zone (80% to 90% RM).

Exercise prescriptions for bone growth stimulation

Baechle & Earle (2001)[1] recommend:

Volume 3 to 6 sets of 10 repetitions
Load 80% to 90% repetition maximum (RM)
Rest 1 to 4 minutes between sets
Variation Undulating periodisation patterns
Exercise selection Structural, multi-joint, large muscle groups


The greater the magnitude or intensity, the higher and faster the power output and the direction of force all contribute to the successful laying down of new bone growth.

Exercise suggestions

To increase lean body mass, add strength and power

  1. Warm-up for 5 to 8 minutes
  2. Squats
  3. Calf raises
  4. Deadlifts
  5. Military Presses
  6. Shoulder shrugs
  7. Abdominal work - two sets of 15 to 20 reps
  8. Bench presses
  9. Barbell rows
  10. Barbell curls
  11. Triceps extensions
  12. Abdominal work again to end the session - two sets of 15 to 20 reps


  • Full-body resistance training program on a schedule of at least two times per week, with three times to optimize the results
  • Utilize the correct exercise technique at all times
  • Three sets of ten to twelve repetitions each exercise unless otherwise noted
  • Work to rest ratio is 1:2, meaning if you work out for ten seconds you then rest for twenty seconds
  • If you can add weight after completing the series three times, then do so the next session
  • If you have increased the weight, then do only ten repetitions and work up to twelve

Article Reference

This article first appeared in:

  • O'DELL, D. (2004) Adaptation of bone to exercise. Brian Mackenzie's Successful Coaching, (ISSN 1745-7513/ 14 / July-August), p. 7-8


  1. BAECHLE, T.R. and EARLE, R.W. (2001) Essentials of Strength Training and Conditioning. Human Kinetics

Page Reference

If you quote information from this page in your work, then the reference for this page is:

  • O'DELL, D. (2004) Adaptation of bone to exercise [WWW] Available from: [Accessed

About the Author

Danny O`Dell is an NSCA Certified Strength and Conditioning coach from the USA. He is the author of several training manuals including The Ultimate Bench Press Manual, Wilderness Basics, Strength training Secrets, Composite training and Power up your Driving Muscles. Danny has published articles in national and international magazines describing the benefits of living a healthy fitness lifestyle.