Gallin J Montgomery1, Grant Abt2, Catherine A Dobson3, Will J Evans4, Mo Aye5, Massimiliano Ditroilo6. 1. Division of Musculoskeletal Science and Sports Medicine, Department of Sport and Exercise Sciences, Manchester Metropolitan University, Manchester, UK - g.montgomery@mmu.ac.uk. 2. Department of Sport, Health and Exercise Science, The University of Hull, Hull, UK. 3. School of Engineering and Computer Science, The University of Hull, Hull, UK. 4. Department of Sport and Exercise Sciences, Faculty of Health Sciences and Wellbeing, University of Sunderland, Sunderland, UK. 5. Center for Metabolic Bone Disease, Hull Royal Infirmary, Hull, UK. 6. School of Public Health, Physiotherapy and Sports Science, University College Dublin, Dublin, Ireland.
Abstract
BACKGROUND: Intermittent mechanical loading generates greater bone adaptations than continuous mechanical loading in rodents but has never been evaluated in humans. This study aimed to evaluate the feasibility of a continuous and intermittent countermovement jump (CMJ) intervention for attenuating early postmenopausal BMD loss. METHODS:41 healthy early postmenopausal women (age=54.6±3.4 years) were randomly assigned to a continuous countermovement jumping group, an intermittent countermovement jumping group or a control group for 12 months. Adherence and dropout rates were recorded along with bone mineral density (BMD) at lumbar spine, femoral neck and trochanter sites at baseline, 6 months and 12 months. RESULTS:28 participants completed the study. Dropout rate during the intervention (from the initiation of exercise) was 36% from continuous and 38% from intermittent countermovement jumping groups. For the participants that completed the intervention, adherence was 60.0±46.8% for continuous and 68.5±32.3% for intermittent countermovement jumping. The control group lost significant lumbar spine BMD (% difference=-2.7 [95%CI: -3.9 to -1.4]) and femoral neck BMD (% difference=-3.0% [95%CI: -5.1 to -0.8]). There was no statistically significant change in BMD for either countermovement jumping group. There was no statistically significant difference in BMD change between continuous or intermittent countermovement jumping groups when compared with the control group. CONCLUSIONS:Adherence and dropout rates were in line with previous similar interventions. To evaluate the effect of continuous and intermittent exercise on BMD, future studies should focus on maintaining participant engagement and adherence to the exercise intervention.
RCT Entities:
BACKGROUND: Intermittent mechanical loading generates greater bone adaptations than continuous mechanical loading in rodents but has never been evaluated in humans. This study aimed to evaluate the feasibility of a continuous and intermittent countermovement jump (CMJ) intervention for attenuating early postmenopausal BMD loss. METHODS: 41 healthy early postmenopausal women (age=54.6±3.4 years) were randomly assigned to a continuous countermovement jumping group, an intermittent countermovement jumping group or a control group for 12 months. Adherence and dropout rates were recorded along with bone mineral density (BMD) at lumbar spine, femoral neck and trochanter sites at baseline, 6 months and 12 months. RESULTS: 28 participants completed the study. Dropout rate during the intervention (from the initiation of exercise) was 36% from continuous and 38% from intermittent countermovement jumping groups. For the participants that completed the intervention, adherence was 60.0±46.8% for continuous and 68.5±32.3% for intermittent countermovement jumping. The control group lost significant lumbar spine BMD (% difference=-2.7 [95%CI: -3.9 to -1.4]) and femoral neck BMD (% difference=-3.0% [95%CI: -5.1 to -0.8]). There was no statistically significant change in BMD for either countermovement jumping group. There was no statistically significant difference in BMD change between continuous or intermittent countermovement jumping groups when compared with the control group. CONCLUSIONS: Adherence and dropout rates were in line with previous similar interventions. To evaluate the effect of continuous and intermittent exercise on BMD, future studies should focus on maintaining participant engagement and adherence to the exercise intervention.