Bone bending strength and BMD of female athletes in volleyball, soccer, and long-distance running.

PURPOSE: The purpose of the study was to determine whether sports training comprised of (1) high-impact loading sport in volleyball (VOL), (2) odd impact loading sport in soccer (SOC), and (3) low impact sport in distance running (RUN) were associated with tibial bending strength and calcaneus bone mineral density (BMD), and ulnar bending strength and wrist BMD. METHOD: Female athletes comprised of 13 VOL, 22 SOC, and 22 RUN participated in the study. Twenty-three female non-athletes (NA) served as the comparison group. Tibial and ulnar bending strength (EI, Nm2) were assessed using a mechanical response tissue analyzer (MRTA). Calcaneus and wrist BMD were assessed using a peripheral X-ray absorptiometry. Group means differences among the study groups were determined using ANCOVA with age, weight, height, percent body fat, ethnicity/race, and training history serving as covariates. RESULTS: Tibial EI of VOL (228.3 ± 138 Nm2) and SOC (208.6 ± 115 Nm2) were greater (p < 0.05) compared to NA (101.2 ± 42 Nm2). Ulnar EI of SOC (54.9 ± 51 Nm2) was higher (p < 0.05) than NA (27.2 ± 9 Nm2). Calcaneus BMD of VOL (0.618 ± 0.12 g/cm2), SOC (0.621 ± 0.009 g/cm2), and RUN (0.572 ± 0.007 g/cm2) were higher (p < 0.05) than NA (0.501 ± 0.08 g/cm2), but not different between athletic groups. Wrist BMD of VOL (0.484 ± .06 g/cm2) and SOC (0.480 ± 0.06 g/cm2) were higher (p < 0.05) than NA (0.443 ± 0.04 g/cm2). CONCLUSIONS: Female VOL athletes exhibit greater tibial bending strength than RUN and NA, but not greater than SOC. Female SOC athletes exhibit greater ulnar bending strength and wrist BMD than NA.

The Impact of Different Modes of Exercise Training on Bone Mineral Density in Older Postmenopausal Women: A Systematic Review and Meta-analysis Research.

Effectiveness of exercise on bone mass is closely related to the mode of exercise training regimen, as well as the study design. This study aimed to determine the effect of different modes of exercise training on lumbar spine and femoral neck bone mineral density (BMD) in older postmenopausal women (PMW). PubMed, CINAHL, Medline, Google Scholar, and Scopus databases and reference lists of included studies were searched up until March 25, 2019 for randomized controlled trials (RCTs) that evaluated the effectiveness of various modes of exercise training in PMW. Sixteen RCTs with 1624 subjects were included. Our study found no significant change in both lumbar spine and femoral neck BMD following exercise training (MD: 0.01 g/cm2; 95% confidence interval (CI) [- 0.01, 0.02] and MD: 0.00 g/cm2; 95% CI [- 0.01, 0.01], respectively). However, subgroup analysis by type of exercise training revealed that lumbar spine BMD (MD: 0.01; 95% CI [0.00, 0.02]) raised significantly when whole-body vibration (WBV) was employed as intervention compared with RCTs that utilized aerobic (MD: - 0.01; 95% CI [- 0.02, - 0.01]), resistance (MD: 0.01; 95% CI [- 0.04, 0.06]), and combined training (MD: 0.03; 95% CI [- 0.01, 0.08]). On the other hand, lumbar spine BMD (MD: - 0.01; 95% CI [- 0.02, - 0.01]) reduced significantly when aerobic exercise training was used as intervention compared with RCTs that utilized resistance training, combined training, and WBV. By contrast, these analyses did not have significant effect on change in femoral neck BMD. WBV is an effective method to improve lumbar spine BMD in older PMW.

Effects of Panax notoginseng (Chinese ginseng) and acute exercise on postprandial glycemia in non-diabetic adults.

The purpose of this study is to determine whether Panax Notoginseng (PNG) taken for 3 days and one 30-min cycling exercise can reduce postprandial hyperglycemia after ingesting a 75-mg oral glucose solution (OGTT) in untrained non-diabetic men, age 20-45 years. We randomly assigned 52 men to: 1) ginseng (G) + exercise (G+Ex, n=14), 2) ginseng (G, n=13), 3) placebo (C) + exercise (C+Ex, n=12), and 4) placebo control groups (C, n=13). The G and C groups took a daily 3g dose of PNG and cornstarch-placebo supplement for 3 days, respectively. The exercise groups also performed a 30-min cycling exercise on day 3 prior to OGTT. The daily 3g-dose of PNG supplementation significantly lowered postprandial plasma glucose (PG) concentration at 30 min post-OGTT in the G group, compared with C (mean Δ±SE: G vs. C = 26.3±11 mg/dl, p<0.05) and PG area under the curve (PG-AUC0-90) in the G and G+Ex groups, relative to the C (G vs. C = 96.5±42 and G+Ex vs. C = 85.2±41 mg/dl, both p<0.05). We conclude that a daily 3g-dose of PNG taken for 3 days, not one acute bout of 30-min cycling exercise at 60% VO2max, lowered postprandial glycemia at 30-min post-OGTT and PG-AUC 0-90 min in non-diabetic men, age 20-45 years.

Dietary salt, bone strength, and mineral content in unloaded rat femurs.

INTRODUCTION: Reduced bone mineral and ultimate strength are regular consequences of unloading bone. The aim of this study was to determine if high dietary salt intake would reduce the bone density and strength to a greater extent in rats with unloaded bones compared to ambulatory control rats fed the same dietary calcium and phosphorus. METHODS: Mature male Sprague-Dawley rats were divided into four groups: two exposed to a spaceflight model that unloaded the hind limbs (HU) and two controls (C) with normal ambulation. Half the HU and C rats were fed normal dietary salt (0.26%, NNa) and half high dietary salt (8%, HNa). The calcium (Ca) and phosphorus (P) content of the diets was normal (Ca 0.5% and P 0.6%) in all four groups. After 4 wk of hind limb unloading, the bone mineral content (BMC) of excised femurs was measured by the ash weight and the ultimate torsional strength was determined by a torsional strength test device. RESULTS: Femoral BMC (mg) was lower in HUNNa than C rats fed normal salt diets. Femurs from HU rats fed normal salt diets showed lower (20-26%) torsional strength (Nmm), compared to all other groups. DISCUSSION: It appears that high salt diets with normal amounts of calcium and phosphorus may prevent the decrease in bone torsional strength and BMC induced by unloading the femurs in 6-mo-old rats.

Bone mineral density and leg muscle strength in young Caucasian, Hispanic, and Asian women.

Differences in bone mineral density (BMD) of ethnically diverse populations are usually attributed to anthropometric characteristics, but may also be due to life style or diet. We studied healthy young sedentary women with Asian (ASN, n=40), Hispanic (HIS, n=39), or Caucasian (CAU, n=36) backgrounds. Body composition and regional BMD were measured by dual-energy X-ray absorptiometry (Hologic) or PIXI (Lunar GE) for the heel and wrist). Leg strength was quantified with a leg press and dietary calcium was estimated with 3-d diet records. CAU were taller than HIS and ASN (p<0.01). ASN had lower body weights, fat mass, lean body mass, and leg strength than HIS or CAU (p<0.01). Differences in BMD among groups were not eliminated by adjusting for body weight and height at the arm, trochanter, femoral neck, and total hip where BMD values remained lower in the ASN than in HIS or CAU (p<0.01). Conversely, adjusted BMD at the wrist was 7.3% higher in ASN and 8.3% higher in HIS and at the heel, 7.3% higher in ASN and 7.0% higher in HIS than in CAU (p<0.05). Leg strength was a significant predictor of BMD in the hip in CAU (R=0.53, p=0.004), in the hip with dietary calcium in ASN (R=0.65, p=0.02), and in the heel with height in HIS (R=0.57, p=0.03). We conclude that significant factors underlying BMD in ethnically diverse young women vary as a function of ethnicity and include leg strength and dietary calcium as well as anthropometric characteristics.

Ulnar and tibial bending stiffness as an index of bone strength in synchronized swimmers and gymnasts.

The purpose of this study is to compare a mechanical property of bone in world-class female athletes with different loading histories. Bone bending stiffness or EI (E is the modulus of elasticity and I, the moment of inertia) was measured noninvasively with the mechanical response tissue analyzer, that analyzes the response of bone to a vibratory stimulus. We evaluated the ulna, ulnar width, wrist density and tibia in 13 synchronized swimmers (SYN), eight gymnasts (GYM) and 16 untrained women (UNT) of similar age. Muscle strength in the flexors and extensors at elbows and knees was measured in the athletes. SYN were taller than GYM or UNT (168 +/- 0.7 vs. 152 +/- 1.1 or 157 +/- 1.2 cm, P < 0.01). Ulnar EI, Nm(2), was similar in SYN and GYM (41 +/- 5.4 vs. 42 +/- 4.2, NS) and 50% higher than in UNT (27 +/- 2.1, P < 0.05). Ulnar EI, Nm(2) was related to ulnar width (r = 0.497, P < 0.002, n = 37) but not to wrist density. Tibial EI, Nm(2), in SYN and GYM (270 +/- 42 vs. 285 +/- 49, NS) was similar and more than twice as high as in UNT (119 +/- 6; p < 0.05). Knee flexor strength measured at 60 degrees s(-1) and elbow extensor strength at 200 degrees s(-1) correlated with tibial EI (r = 0.44 and 0.41, P < 0.05). In spite of different loading histories, the tibiae and ulnas of world-class athletes showed similar high values for bending stiffness that exceeded values in untrained women. EI in the ulna could be related to bone width and in the tibia, to muscle strength.

Panax notoginseng supplementation enhances physical performance during endurance exercise.

The purpose of this study was to investigate whether a single 1,350-mg dose of Panax notoginseng (PNG) could enhance aerobic capacity, endurance, and mean blood pressure (MAP) in young adults. We randomly assigned 29 untrained adults, aged 20-35 years, to an experimental (EXP, n = 13) or a control (CON, n = 16) group. For 30 days, the EXP took 1,350 mg per day of PNG capsule and the CON consumed 1,350 mg per day of starch capsule. Measurement variables were taken before and after 30 days of either PNG supplement or placebo. Results show that the EXP improved (p < 0.05) their endurance time by >7 minutes, and lowered (p < 0.05) maximal MAP (from 113 +/- 12 to 109 +/- 14 mm Hg) and Vo2 at the 24th minute (from 32.5 +/- 8 to 27.6 +/- 8 ml.kg-1.min-1) during endurance cycle exercise. Based on this study, we conclude that 1,350 mg per day PNG supplement for 30 days improved endurance time to exhaustion, and lowered MAP and Vo2 during endurance exercise.