Importance of Resistance Training for Females to Reduce the Risk of Osteoporosis

Osteoporosis is sometimes referred to as “The Silent Thief” because females lose bone mineral density without knowing it (National Institutes of Health Osteoporosis and Related Bone Diseases). Osteoporosis primarily affects postmenopausal women, but prevention must start with premenopausal clients. Osteoporotic bone breaks occur in the thoracic vertebrae, hips (head of the femur), and wrists. Thoracic vertebrae and hip fractures can be life threatening, therefore resistance training is imperative for female fitness clients. Prevention of osteoporosis must include exercises such as upper body pushing/pulling, neutral spine core training, squats, and lunges. The critical component of resistance training is the mechanical loading of the muscle pulling on a tendon to move a joint with tension on the origin and insertion on the bone, which helps improve bone mineral density, or prevent the loss of density.

Learning Objectives

1. Understand why women lose bone mineral density as they age.
2. Describe how mechanical loading of the muscle, tendon, and bone can increase bone mineral density or reduce its loss.
3. Prescribe an osteoporosis prevention program for female clients.

In this day and age in the fitness industry, there are too many people who are undereducated and over-certified and know a limited amount about the fitness training that is important for their clients. Many people who claim to be fitness professionals present a “personality” instead of sound objective training programs for fitness clients. Many fitness personalities offer training programs designed to be flashy and burn maximum calories in the attempt to improve outward appearance. On the other hand, many educated fitness professionals understand the importance of designing training programs that focus on the individual needs of the client. It is these fitness pro’s who understand the importance of applying specific exercises for the prevention of osteoporosis for female clients.

The National Osteoporosis Foundation (NOF) estimates there are 10 million Americans with osteoporosis and 8 million are female. It is further estimated that one in two women over 50 years old will break a bone because of osteoporosis. Women have a higher risk of osteoporosis because they have smaller and thinner bones than men. Regarding menopause, the hormone estrogen, which helps strengthen bones, decreases rapidly during menopause, which can cause bone mineral density to decrease.

Generic Advice for Exercise to Prevent Osteoporosis

Many of the organizations whose mission is to inform consumers about osteoporosis give perhaps the most generic advice about exercise they could possibly think of. And clearly, many of these organizations never consulted an exercise professional to give specific advice about exercises that can have a dramatic impact on preventing osteoporosis.

The National Osteoporosis Foundation, for instance, suggests that women consult with a physical therapist before starting the exercises they recommend. No disrespect to physical therapists, but their expertise is in injury management and rehabilitation and not in prescribing exercises for females wanting to prevent osteoporosis. This is a scope of practice issue. This organization suggests the following exercises for women to supposedly improve bone mineral density: Corner Stretch for the Upper Body, Standing Hip Abduction, Prone Leg Lifts, Heel Raises, and Wall Sit, none of which specifically focus on the body parts affected by osteoporosis and increased risk of bone facture.

Even the National Institutes of Health Osteoporosis and Related Bone Diseases offers equally generic advice for exercise. This organization suggest weight-bearing and resistance exercises, which is a good start, but offer no specific exercises. They do say that weight-bearing exercises include walking, hiking, jogging, climbing stairs, playing tennis, and dancing. These activities will help the head of the femur but will do nothing for the thoracic vertebrae. And finally, they offer that resistance exercises can include lifting weights and using weight training machines, but still no specific exercises for women to use.

The Etiology of Resistance Training for Osteoporosis Prevention

Mechanical loading on the bone from resistance training can lead to an increase in the cross-sectional area and density of bones. Mechanical loading is site-specific, meaning that in order to increase bone mineral density of specific areas of the body, resistance training must be focused on the areas where osteoporosis affects women: thoracic vertebrae, head of the femur, and the wrists (Hong and Kim, 2018). Symptoms of thoracic vertebral fracture can include pain, curvature of the spine (Dowagers Hump), height loss, difficulties with activities of daily living, loss of self-esteem related to changes in body shape, and in severe cases, respiratory and gastrointestinal problems. In addition, vertebral fractures are linked to mortality. Both thoracic vertebral fractures and hip fractures can be life threatening.

Bone adapts quickly to repeated patterns of loading, such as one-directional movement or the same exercise done repeatedly. As such, a variation of loading, such as multi-directional training, is required to continually stimulate an adaptive response. This means that a variety of exercises are best to use for maximal bone loading (Hong and Kim, 2018).

Hong and Kim (2018) suggest there are no life-long studies to use as evidence, but research suggests that adaptations to mechanical loading in kids and adolescents are translated to greater bone strength as women age. Bone remodeling becomes less sensitive to resistance training after skeletal maturity is reached at 18 - 25 years of age. Bones are more responsive to resistance training in childhood than in adulthood and old age. However, considering the evidence showing the capability of weight-bearing activities on reducing bone loss in older women, resistance training for older clients is still very important.

Hong and Kim (2018) suggest a combination of resistance training and weight-bearing aerobic exercise (e.g., running, skipping, jumping, or high-impact aerobics) is recommended. This combination has shown to improve bone mineral density, muscle mass, and strength in older women.

Resistance Exercises to Improve Bone Mineral Density

Considering that osteoporosis primarily affects three areas on the body (thoracic vertebrae, head of the femur, and distal wrists) is it wise to include exercises that will put a load on the bones of these body parts.

Exercises for the Thoracic Vertebrae

1. Standing Row – 1-arm at a time - performed with a cable or rubber resistance.
2. Seated Row – performed with a cable, row machine or rubber resistance.
3. Standing Partner Resistance Pull – holding hands in a “thumb grip,” one partner pulls while the other partner resists the pull, then the pull and resistance is reversed.
4. Lat Pulldown

Exercises for the Head of the Femur

1. Squats Holding Free Weights – hold a dumbbell in each hand or hold a Medicine Ball close to the body while performing good technical squats (specific instruction on proper squat technique is important for clients).
2. Lunges Holding Free Weights – hold a dumbbell in each hand or hold a Medicine Ball close to the body while performing good technical lunges (specific instruction on proper lunge technique is important for clients). This exercise is also good for improving balance.
3. Seated Leg Press
4. Wall Stability Ball Sits – place a stability ball between a wall and the thoracic spine, slowly squat to between 90 – 120 degrees of knee flexion.
5. Box Step Ups – perform this exercise on a box that is approximately 12 inches high, and can be performed without weights or while holding dumbbells in each hand.

Exercises for the Wrist

1. Push-ups – perform the push-ups on toes, knees, or with hands elevated on a box.
2. Machine Chest Press
3. Bench Press
4. Dumbbell Chest Press – this exercise can be done on a stable surface, such as a bench, or on an unstable surface, such as a stability ball (the thoracic spine would be on the ball and the trainer will hand the dumbbells to the client for safety).
5. Standing Rubber Resistance Chest Press – the rubber resistance is anchored behind the client, and the client presses the resistance forward using 1-arm or both arms.

Sets and Repetitions

Kraemer and Ratamas (2004) indicate the following for sets and repetitions:
Muscle Power: 1 – 5 reps - using resistance that will allow the client to perform a maximum of 5 reps.

Muscle Strength/Hypertrophy: 6 – 15 reps – using resistance that will allow client to perform a maximum of 8 reps for strength and 12 – 15 for hypertrophy.
Muscle Endurance: 16 – 20 reps – using resistance that will allow the client to perform a maximum of 20 reps.

For osteoporosis prevention, it is best to use an exercise prescription of strength/hypertrophy and endurance.

References

Hong, A.R. and Kim, S.W (2018) Effects of Resistance Exercise on Bone Health, Endocrinology and Metabolism, 33(4): 435–444.

Kraemer, W. J., and Ratamas, N. A. (2004) Fundamentals of Resistance Training: Progression and Exercise Prescription. Medicine and Science in Sports and Exercise, 36(4):674-688.

National Osteoporosis Foundation, https://www.nof.org/preventing-fractures/general-facts/what-women-need-to-know/, Retrieved September, 25, 2019.

National Institutes of Health Osteoporosis and Related Bone Diseases, https://www.bones.nih.gov/health-info/bone/osteoporosis/overview, Retrieved September, 25, 2019.