Bone mineral density and hip structure changes over one-year in collegiate distance runners and non-athlete controls

Comparison of bone mineral density of runners with inactive males: A cross-sectional 4HAIE study

The purpose of the study was to determine whether running is associated with greater bone mineral density (BMD) by comparing the BMD of regularly active male runners (AR) with inactive nonrunner male controls (INC). This cross-sectional study recruited 327 male AR and 212 male INC (aged 18-65) via a stratified recruitment strategy. BMD of the whole body (WB) and partial segments (spine, lumbar spine (LS), leg, hip, femoral neck (FN), and arm for each side) were measured by dual-energy x-ray absorptiometry (DXA) and lower leg dominance (dominant-D/nondominant-ND) was established by functional testing. An ANCOVA was used to compare AR and INC. The AR had greater BMD for all segments of the lower limb (p<0.05), but similar BMD for all segments of the upper limb (p>0.05) compared with INC. Based on the pairwise comparison of age groups, AR had greater BMD of the ND leg in every age group compared with INC (p<0.05). AR had grater BMD of the D leg in every age group except for (26-35 and 56-65) compare with INC (p<0.05). In the youngest age group (18-25), AR had greater BMD in every measured part of lower extremities (legs, hips, femoral necks) compared with INC (p<0.05). In the 46-55 age group AR had greater BMD than INC (p < 0.05) only in the WB, D Leg, D neck, and ND leg. In the 56-65 age group AR had greater BMD than INC (p<0.05) only in the ND leg. Overall, AR had greater BMD compared with INC in all examined sites except for the upper limbs, supporting the notion that running may positively affect bone parameters. However, the benefits differ in the skeletal sites specifically, as the legs had the highest BMD difference between AR and INC. Moreover, the increase in BMD from running decreased with age.

Effects of Exercise and Sports Intervention and the Involvement Level on the Mineral Health of Different Bone Sites in the Leg, Hip, and Spine: A Systematic Review and Meta-Analysis

The current study analysed whether the osteogenic stimuli of exercises and sports have an independent effect on bone mineral density (BMD). Studies with a design having two different cohorts were searched and selected to distinguish the effect due to long-term involvement (i.e., athletes vs. non-active young with good bone health) and due to the planning of intervention (i.e., pre- vs. post-training) with exercises and sports. Moreover, only studies investigating the bone sites with a body-weight support function (i.e., lower limb, hip, and spine regions) were reviewed, since the osteogenic effects have incongruous results. A meta-analysis was performed following the recommendations of PRISMA. Heterogeneity (I2) was determined by combining Cochran's Q test with the Higgins test, with a significance level of α = 0.05. The studies reporting the effect of involvement in exercise and sports showed high heterogeneity for the lower limb, total hip, and spine (I2 = 90.200%, 93.334%, and 95.168%, respectively, with p < 0.01) and the effect size on sports modalities (Hedge's g = 1.529, 1.652, and 0.417, respectively, with p < 0.05) ranging from moderate to high. In turn, the studies reporting the effect of the intervention planning showed that there was no heterogeneity for the lower limb (I2 = 0.000%, p = 0.999) and spine (I2 = 77.863%, p = 0.000); however, for the hip, it was moderate (I2 = 49.432%, p = 0.054), with a low effect between the pre- and post-training moments presented only for the hip and spine (Hedge's g = 0.313 and 0.353, respectively, with p < 0.05). The current analysis supported the effect of involvement in exercise and sports by evidencing the effect of either weight-bearing or non-weight-bearing movements on BMD at the femoral, pelvic, and lumbar bones sites of the athletes when comparing to non-athletes or non-active peers with healthy bones. Moreover, the effect of different exercise and sports interventions highlighted the alterations in the BMD in the spine bone sites, mainly with long-term protocols (~12 months) planned with a stimulus with high muscle tension. Therefore, exercise and sport (mainly systematic long-term practice) have the potential to increase the BMD of bones with body-weight support beyond the healthy values reached during life phases of youth and adulthood.

The Relationship Between Muscular Strength, Jump Power, and Bone Health in Collegiate Distance Runners

Participation in sports, especially those involving impact loading, enhance bone mineral content (BMC) and density (BMD). Additionally, participation in impact loading sports may strengthen relationships between strength or power and bone variables. The purpose of this investigation was to examine relationships between measures of muscular performance and bone variables in Division I endurance athletes (29 males, 31 females, 19.6 ± 1.4 years). Dual-energy x-ray absorptiometry (DXA) scans were analyzed at the anterior-posterior (AP) and lateral (LAT) spine, femoral neck (FN), total hip (TH), whole body (WB), and ultra-distal forearm (UD) for BMC and BMD measures. WB scans provided information for bone-free lean mass (BFLM). Performance measures included absolute, and relative (to body weight), grip strength (GS) and absolute lower body power (LBP) derived from a vertical jump. Pearson correlation coefficients were determined between bone variables and muscular performance measures. Hierarchical multiple regression was used to quantify the variance explained in bone variables. Male runners showed strong relationships between absolute and relative GS and numerous bone variables. Female runner had significant relationships between absolute jump power and numerous bone variables. Sex, GS, and LBP explained 41-76% of BMC at the various bone sites and 12-30% of BMD. Results indicate that in collegiate men, greater strength is related to higher BMC and BMD, however this was not the case for women. In female collegiate distance runners, higher jump power was related to greater BMC and BMD.

Bone mineral density in response to increased energy intake in exercising women with oligomenorrhea/amenorrhea: the REFUEL randomized controlled trial

BACKGROUND

Energy deficiency can result in menstrual disturbances and compromised bone health in women, a condition known as the Female Athlete Triad.

OBJECTIVES

The REFUEL randomized controlled trial assessed the impact of increased energy intake on bone health and menstrual function in exercising women with menstrual disturbances.

METHODS

Exercising women with oligomenorrhea/amenorrhea (Oligo/Amen) were randomly assigned to an intervention group (Oligo/Amen + Cal, n = 40, mean ± SEM age: 21.3 ± 0.5 y; weight: 55.0 ± 1.0 kg; BMI: 20.4 ± 0.3 kg/m2) who increased energy intake 20%-40% above baseline energy needs for 12 mo or a control group (Oligo/Amen Control, n = 36; mean ± SEM age: 20.7 ± 0.5 y; weight: 59.1 ± 1.3 kg; BMI: 21.3 ± 0.4 kg/m2). Energy intake and expenditure, metabolic and reproductive hormones, body composition, and areal bone mineral density (aBMD) were assessed.

RESULTS

Oligo/Amen + Cal improved energy status [increased body mass (2.6 ± 0.4 kg), BMI (0.9 ± 0.2 kg/m2), fat mass (2.0 ± 0.3 kg), body fat percentage (2.7% ± 0.4%), and insulin-like growth factor 1 (37.4 ± 14.6 ng/mL)] compared with Oligo/Amen Control and experienced a greater likelihood of menses (P < 0.05). Total body and spine aBMD remained unchanged (P > 0.05). Both groups demonstrated decreased femoral neck aBMD at month 6 (-0.006 g/cm2; 95% CI: -0.011, -0.0002 g/cm2 ; time main effect P = 0.043) and month 12 (-0.011 g/cm2; 95% CI: -0.021, -0.001 g/cm2; time main effect P = 0.023). Both groups demonstrated a decrease in total hip aBMD at month 6 (-0.006 g/cm2; 95% CI: -0.011, -0.002 g/cm2; time main effect P = 0.004).

CONCLUSIONS

Although higher dietary energy intake increased weight, body fat, and menstrual frequency, bone mineral density was not improved, compared with the control group. The 12-mo intervention may have been too short and the increase in energy intake (∼352 kcal/d), although sufficient to increase menstrual frequency, was insufficient to increase estrogen or improve aBMD. Future research should refine the optimal nutritional and/or pharmacological interventions for the recovery of bone health in athletes and exercising women with Oligo/Amen.This trial was registered at clinicaltrials.gov as NCT00392873.