Category Archives: Exercise

Review: Exercise Program Design

Abstract

Exercise for patients with osteoporosis: management of vertebral compression fractures and trunk strengthening for fall prevention.

Maintenance of bone health and quality requires mechanical strain, but the mechanical force needs to be within the bone’s biomechanical competence. In osteoporosis, compression of vertebral bodies can be insidious. Therefore, absence of pain does not necessarily indicate absence of vertebral microfracture and deformity. Further, patients with previous vertebral fractures are at risk for further vertebral fractures and their associated morbidity. Exercise is a part of the comprehensive management of patients with osteoporosis and has been associated with improvement of quality of life and lowered risk of future fracture. The exercise prescription needs to match the needs of the patient. If exercise is not prescribed properly, then it may have negative consequences. In general, an exercise program, therapeutic or recreational, needs to address flexibility, muscle strength, core stability, cardiovascular fitness, and gait steadiness. As with pharmacotherapy, therapeutic exercises need to be individualized on the basis of musculoskeletal status and an individual’s exercise interest. In osteoporosis, axial strength and stability are of primary importance. In particular, a spinal extensor strengthening program should be performed with progressive measured resistance as tolerated. To address falls and fractures, an exercise program should also include balance and lower extremity strength training. Proper dosing of oral cholecalciferol and calcium supplements can enhance the effect of strengthening exercises. Finally, a coordinated approach, such as the Spinal Proprioception Extension Exercise Dynamic (SPEED) program, can improve back extensor strength, the level of physical activity, and locomotion, and reduce back pain and fear and risk of falls.

Sinaki M
PM R Nov 2012
PMID: 23174554

Alendronate + Exercise Prevents All Bone Loss During Spaceflight

Abstract

Bisphosphonates as a supplement to exercise to protect bone during long-duration spaceflight.

We report the results of alendronate ingestion plus exercise in preventing the declines in bone mass and strength and elevated levels of urinary calcium and bone resorption in astronauts during 5.5 months of spaceflight.
This investigation was an international collaboration between NASA and the JAXA space agencies to investigate the potential value of antiresorptive agents to mitigate the well-established bone changes associated with long-duration spaceflight.
We report the results from seven International Space Station (ISS) astronauts who spent a mean of 5.5 months on the ISS and who took an oral dose of 70 mg of alendronate weekly starting 3 weeks before flight and continuing throughout the mission. All crewmembers had available for exercise a treadmill, cycle ergometer, and a resistance exercise device. Our assessment included densitometry of multiple bone regions using X-ray absorptiometry (DXA) and quantitative computed tomography (QCT) and assays of biomarkers of bone metabolism.
In addition to pre- and post-flight measurements, we compared our results to 18 astronauts who flew ISS missions and who exercised using an early model resistance exercise device, called the interim resistance exercise device, and to 11 ISS astronauts who exercised using the newer advanced resistance exercise device (ARED). Our findings indicate that the ARED provided significant attenuation of bone loss compared with the older device although post-flight decreases in the femur neck and hip remained. The combination of the ARED and bisphosphonate attenuated the expected decline in essentially all indices of altered bone physiology during spaceflight including: DXA-determined losses in bone mineral density of the spine, hip, and pelvis, QCT-determined compartmental losses in trabecular and cortical bone mass in the hip, calculated measures of fall and stance computed bone strength of the hip, elevated levels of bone resorption markers, and urinary excretion of calcium.
The combination of exercise plus an antiresoptive drug may be useful for protecting bone health during long-duration spaceflight.

Leblanc A, Matsumoto T, Jones J, Shapiro J…
Osteoporos Int Jul 2013
PMID: 23334732

Biking May Help Bones Affected by High Cortisol

Abstract

Effect of physiological exercise on osteocalcin levels in subjects with adrenal incidentaloma.

In the present study, we have evaluated whether physical exercise affect low osteocalcin concentrations observed in patients with subclinical hypercortisolism.
Sixteen patients (10 men and 6 women, age 38-55 yr) with adrenal incidentaloma were studied. Fifteen healthy volunteers matched for age (range 35-47 yr) were used as controls. Subjects were submitted to a 8-week exercise-training program with cycle-ergometer for 1 h/day 3-4 days/week at 60% of their individual VO2 max. Before and after this period, resting venous serum osteocalcin and GH concentrations were measured in the same batch. The blood sampling after 8 weeks of the training program were performed after resting for one day. All patients and controls underwent also the following endocrine evaluation: serum cortisol, plasma ACTH.
Our results demonstrate a significant increase of osteocalcin after physical exercise and a positive correlation between osteocalcin and GH. This later might suggest a role of GH in the increased osteocalcin secretion.
The data of the present study suggest a positive effect of physical exercise on bone metabolism in patients with adrenal incidentaloma.

Coiro V, Volpi R, Cataldo S, Magotti MG…
J. Endocrinol. Invest. Apr 2012
PMID: 22652825

It is surprising the exercise helped considering the form of exercise was cycling – a non-weight bearing exercise.

Resistance Exercise Prevents Bone Loss During Spaceflights

Abstract

Benefits for bone from resistance exercise and nutrition in long-duration spaceflight: Evidence from biochemistry and densitometry.

Exercise has shown little success in mitigating bone loss from long-duration spaceflight. The first crews of the International Space Station (ISS) used the “interim resistive exercise device” (iRED), which allowed loads of up to 297 lb(f) (or 1337 N) but provided little protection of bone or no greater protection than aerobic exercise. In 2008, the Advanced Resistive Exercise Device (ARED), which allowed absolute loads of up to 600 lb(f) (1675 N), was launched to the ISS. We report dietary intake, bone densitometry, and biochemical markers in 13 crewmembers on ISS missions from 2006 to 2009. Of these 13, 8 had access to the iRED and 5 had access to the ARED. In both groups, bone-specific alkaline phosphatase tended to increase during flight toward the end of the mission (p = 0.06) and increased 30 days after landing (p < 0.001). Most markers of bone resorption were also increased in both groups during flight and 30 days after landing (p < 0.05). Bone densitometry revealed significant interactions (time and exercise device) for pelvis bone mineral density (BMD) and bone mineral content (p < 0.01), hip femoral neck BMD (p < 0.05), trochanter BMD (p < 0.05), and total hip BMD (p < 0.05). These variables were unchanged from preflight only for ARED crewmembers, who also returned from flight with higher percent lean mass and lower percent fat mass. Body mass was unchanged after flight in both groups. All crewmembers had nominal vitamin D status (75 ± 17 nmol/L) before and during flight. These data document that resistance exercise, coupled with adequate energy intake (shown by maintenance of body mass determined by dual-energy X-ray absorptiometry [DXA]) and vitamin D, can maintain bone in most regions during 4- to 6-month missions in microgravity. This is the first evidence that improving nutrition and resistance exercise during spaceflight can attenuate the expected BMD deficits previously observed after prolonged missions.

Smith SM, Heer MA, Shackelford LC, Sibonga JD…
J. Bone Miner. Res. Sep 2012
PMID: 22549960

Physical Activity Associated with Higher Bone Density in Chinese Women

Abstract

[Physical activity and bone mineral density in postmenopausal women].

To test the association of total and physical activity (PA) intensity levels with bone mineral density (BMD) and bone mineral content (BMC) in postmenopausal women.
315 postmenopausal women (50-70 y) were recruited for this cross-sectional study from community residents in Guangzhou, China. PA and related covariates including general characteristics and dietary intakes were assessed using a face-to-face interview. BMD and BMC were determined by a dual energy x-ray absorptiometry, at the whole body, lumbar spine (L1-AL4), total hip and its sub-sites.
The participants were tertiled according to metabolic equivalent (MET) of PA. Analysis of covariance showed that greater PA tended to correlated to better BMD and BMC at various sites. Mean (S) BMDs at the whole body were (1.045 +/- 0.008), (1.043 +/- 0.008), (1.068 +/- 0.008) g/cm2 in the tertile I, II and III of total PA. BMD was significantly higher in the tertile III than those in the tertile I (P = 0. 049) and II (P = 0.028). No significant difference was observed at other sites. Mean BMC was significantly higher in the of highest total PA group than those in the other two groups at total femur, femoral neck, shaft femur and ward’s triangle (P = 0. 004-0. 042). The association was differed by PA intensity levels. BMD tended to be increased with less light-intensity PA, more moderate-intensity PA and moderate vigorous-intensity PA.
Greater total PA and moderate-intensity PA, and moderate vigorous-intensity PA might improve bone mass in postmenopausal women.

Zhong W, Li J, Huang Z, Yang X…
Wei Sheng Yan Jiu Mar 2012
PMID: 22611928

A Positive Study on Vibration With or Without Exercise

Abstract

Whole-body vibration effects on bone mineral density in women with or without resistance training.

Whole-body vibration exposure may translate into improved bone mass in young adult women. The primary focus of this study was to examine the effects of graded whole-body vibration or vibration exposure plus resistance training on bone mineral density (BMD), hematological measures for bone remodeling, and exercise metabolism in young women.
There were 51 healthy active women [mean (SD) age, 21.02 (3.39) yr; height, 165.66 (6.73) cm; body mass 66.54 (13.39) kg] who participated in the intervention. Subjects were randomly assigned to whole-body vibration (WBV), whole-body vibration plus resistance training (WBV+RT), or control (CONT) groups for 16 wk.
A repeated-measure ANOVA found no significant (P < 0.05) group differences in BMD at the completion of 16 wk. A significant within group change was apparent for the WBV (2.7% femoral neck) and WBV+RT (femoral neck 1.9%; vertebra 0.98%). WBV and WBV+RT experienced a significant (P < 0.05) 60% and 58% increase in adiponectin, 48% and 30% in transforming growth factor-beta1, and 17% and 34% in nitric oxide with an accompanying 50% and 36% decrease in osteopontin, 19% and 34% in interleukin-1beta, and 38% and 39% in tumor necrosis factor-alpha.
The results indicate graded whole-body vibration exposure may be effective in improving BMD by increasing bone deposition while also decreasing bone resorption. Whole-body vibration may also provide an efficient stratagem for young women to achieve peak bone mass and help stave off osteoporosis later in life and provide a novel form of physical training.

Humphries B, Fenning A, Dugan E, Guinane J…
Aviat Space Environ Med Dec 2009
PMID: 20027849

Alendronate Suppresses Bone Formation From Exercise in Rats

Abstract

Cancellous bone formation response to simulated resistance training during disuse is blunted by concurrent alendronate treatment.

The purpose of this study was to assess the effectiveness of simulated resistance training (SRT) exercise combined with alendronate (ALEN) in mitigating or preventing disuse-associated losses in cancellous bone microarchitecture and formation. Sixty male Sprague-Dawley rats (6 months old) were randomly assigned to either cage control (CC), hind limb unloading (HU), HU plus either ALEN (HU + ALEN), SRT (HU + SRT), or a combination of ALEN and SRT (HU + SRT/ALEN) for 28 days. HU + SRT and HU + SRT/ALEN rats were anesthetized and subjected to muscle contractions once every 3 days during HU (four sets of five repetitions, 1000 ms isometric + 1000 ms eccentric). Additionally, HU + ALEN and HU + SRT/ALEN rats received 10 µg/kg of body weight of ALEN three times per week. HU reduced cancellous bone-formation rate (BFR) by 80%, with no effect of ALEN treatment (-85% versus CC). SRT during HU significantly increased cancellous BFR by 123% versus CC, whereas HU + SRT/ALEN inhibited the anabolic effect of SRT (-70% versus HU + SRT). SRT increased bone volume and trabecular thickness by 19% and 9%, respectively, compared with CC. Additionally, osteoid surface (OS/BS) was significantly greater in HU + SRT rats versus CC (+32%). Adding ALEN to SRT during HU reduced Oc.S/BS (-75%), Ob.S/BS (-72%), OS/BS (-61%), and serum TRACP5b (-36%) versus CC. SRT and ALEN each independently suppressed a nearly twofold increase in adipocyte number evidenced with HU and inhibited increases in osteocyte apoptosis. These results demonstrate the anabolic effect of a low volume of high-intensity muscle contractions during disuse and suggest that both bone resorption and bone formation are suppressed when SRT is combined with bisphosphonate treatment.

Swift JM, Swift SN, Nilsson MI, Hogan HA…
J. Bone Miner. Res. Sep 2011
PMID: 21509821

Similar Results From Minimal vs. High Resistance Exercise in Rats

Abstract

Increased training loads do not magnify cancellous bone gains with rodent jump resistance exercise.

This study sought to elucidate the effects of a low- and high-load jump resistance exercise (RE) training protocol on cancellous bone of the proximal tibia metaphysis (PTM) and femoral neck (FN). Sprague-Dawley rats (male, 6 mo old) were randomly assigned to high-load RE (HRE; n = 16), low-load RE (LRE; n = 15), or sedentary cage control (CC; n = 11) groups. Animals in the HRE and LRE groups performed 15 sessions of jump RE during 5 wk of training. PTM cancellous volumetric bone mineral density (vBMD), assessed by in vivo peripheral quantitative computed tomography scans, significantly increased in both exercise groups (+9%; P < 0.001), resulting in part from 130% (HRE; P = 0.003) and 213% (LRE; P < 0.0001) greater bone formation (measured by standard histomorphometry) vs. CC. Additionally, mineralizing surface (%MS/BS) and mineral apposition rate were higher (50-90%) in HRE and LRE animals compared with controls. PTM bone microarchitecture was enhanced with LRE, resulting in greater trabecular thickness (P = 0.03) and bone volume fraction (BV/TV; P = 0.04) vs. CC. Resorption surface was reduced by nearly 50% in both exercise paradigms. Increased PTM bone mass in the LRE group translated into a 161% greater elastic modulus (P = 0.04) vs. CC. LRE and HRE increased FN vBMD (10%; P < 0.0001) and bone mineral content (∼ 20%; P < 0.0001) and resulted in significantly greater FN strength vs. CC. For the vast majority of variables, there was no difference in the cancellous bone response between the two exercise groups, although LRE resulted in significantly greater body mass accrual and bone formation response. These results suggest that jumping at minimal resistance provides a similar anabolic stimulus to cancellous bone as jumping at loads exceeding body mass.

Swift JM, Gasier HG, Swift SN, Wiggs MP…
J. Appl. Physiol. Dec 2010
PMID: 20930128 | Free Full Text

Review: Exercise and Bone Markers

Abstract

Bone metabolism markers in sports medicine.

Bone mass can be viewed as the net product of two counteracting metabolic processes, bone formation and bone resorption, which allow the skeleton to carry out its principal functions: mechanical support of the body, calcium dynamic deposition and haemopoiesis. Besides radiological methods, several blood and urinary molecules have been identified as markers of bone metabolic activity for estimating the rates and direction of the biological activities governing bone turnover. The advantages for the use of bone metabolism markers are that they are potentially less dangerous than radiological determinations, are more sensitive to changes in bone metabolism than radiological methods and are easily collected and analysed. The disadvantages are that they have high biological variability. Physical exercise is a known source of bone turnover and is recommended for preventing osteoporosis and bone metabolism problems. There are numerous experiments on bone metabolism markers after acute exercise, but not after long-term training and during or after a whole competition season. Moreover, few studies on bone metabolism markers have evaluated their performance in elite and top-level athletes, who have a higher bone turnover than sedentary individuals. Despite discrepant results among studies, most have shown that short exercise is insufficient for modifying serum concentrations of bone metabolism markers. Marker variations are more evident after several hours or days after exercise, bone formation markers are more sensitive than bone resorption markers, and stimulation of osteoblast and/or osteoclast functions is exercise dependent but the response is not immediate. The response depends on the type of exercise; the markers seem to be less sensitive to resistance exercise and the intensity of exercise is not discriminate. Comparisons between trained subjects and untrained controls have demonstrated the influence of exercise on bone turnover. During training, carboxy-terminal collagen cross-links (CTx), a bone resorption marker, was shown to be less sensitive than amino-terminal cross-linking telopeptide of type I collagen (NTx) and urinary pyridinolines, which were sensitive to anaerobic exercise. Whereas, the bone formation markers, bone alkaline phosphatase (BAP) and osteocalcin (OC) changed after 1 month and 2 months of an exercise programme, respectively. After 2 months, while BAP normalized, it was found to be sensitive to aerobic exercise and OC was found to be sensitive to anaerobic exercise. After prolonged training and competition, bone formation markers are found to change in sedentary subjects enrolled in a physical activity programme. Professional athletes show changes in bone formation markers depending on programme intensity, whereas bone resorption appears to stabilize. Crucial for long-term training, are the characteristics of exercise (e.g. weight-bearing, impact).

Banfi G, Lombardi G, Colombini A, Lippi G
Sports Med Aug 2010
PMID: 20632739

Aerobic and Resistance Exercise May Increase Bone Formation in Young Women

Abstract

Influence of exercise mode and osteogenic index on bone biomarker responses during short-term physical training.

Prescribing exercise based on intensity, frequency, and duration of loading may maximize osteogenic responses in bone, but a model of the osteogenic potential of exercise has not been established in humans. In rodents, an osteogenic index (OI) has been used to predict the osteogenic potential of exercise. The current study sought to determine whether aerobic, resistance, or combined aerobic and resistance exercise programs conducted over eight weeks and compared to a control group could produce changes in biochemical markers of bone turnover indicative of bone formation. We further sought to determine whether an OI could be calculated for each of these programs that would reflect observed biochemical changes. We collected serum biomarkers [bone-specific alkaline phosphatase (BAP), osteocalcin, tartrate-resistant acid phosphatase (TRAP), C-terminal telopeptide fragment of type I collagen (CTx), deoxypyridinoline (DPD), 25-hydroxy vitamin D (25(OH)D), and parathyroid hormone (PTH)] in 56 women (20.3+/-1.8 years) before, during and after eight weeks of training. We also measured bone mineral density (BMD) at regional areas of interest using DXA and pQCT. Biomarkers of bone formation (BAP and osteocalcin) increased in the Resistance and Combined groups (p<0.05), while biomarkers of bone resorption (TRAP and DPD) decreased and increased, respectively, after training (p<0.05) in all groups. Small changes in volumetric and areal BMD (p<0.05) were observed in the distal tibia in the Aerobic and Combined groups, respectively. Mean weekly OIs were 16.0+/-1.9, 20.6+/-2.2, and 36.9+/-5.2 for the Resistance, Aerobic, and Combined groups, respectively. The calculated osteogenic potential of our programs did not correlate with the observed changes in biomarkers of bone turnover. The results of the present study demonstrate that participation in an eight week physical training program that incorporates a resistance component by previously inactive young women results in alterations in biomarkers of bone remodeling indicative of increased formation without substantial alterations in markers of resorption.

Lester ME, Urso ML, Evans RK, Pierce JR…
Bone Oct 2009
PMID: 19520194