Effects of a sixteen-weeks high-speed resistance training program on bone mineral density and content in Independent Older Adults

Abstract

Introduction The United Nations estimates 1.5 billion people aged over 65 years in 2025, compared with 703 million in 2019 (1). Unfortunately, the aging process involves the development of many chronic diseases, namely osteoporosis. Osteoporosis is characterized by low bone mass and microarchitectural deterioration of bone tissue (2). Reduced bone mineral density (BMD) and bone mineral content (BMC) with age increase the likelihood of fall-related fractures (3). A recent meta-analysis recommended the use of resistance training programs for increasing BMD and BMC in older adults (4). This study examined the effects of a 16-weeks high-speed resistance training (HSRT) program on BMD and BMC. Methods: This study included 21 independent older adults (age, 69.00±4.32 years). The HSRT program lasted 16 weeks, with 3 sessions per week of 50–60min, each session of 5–6 exercises, 2–3 sets, and 6–10 reps/exercise. The intensity was gradually increased after each session in accordance with the movement velocity (>1.3–0.75 m/s) representing approximately 20% to 60% of one repetition maximum. Participants executed the exercises rapidly and explosively, making all repetitions for each shortening phase (concentric phase) performed as quickly as possible with the lengthening phase of the muscle (eccentric phase) being controlled for 2–3sec. The velocity of the concentric phase in each exercise was monitored by a BEAST™ sensor (Beast Technologies, Brescia, Italy). BMD and BMC for whole-body and dominant femoral neck were measured by dual-energy X-ray absorptiometry. The Ethics Committee of the University of Évora approved the study. The protocol was registered at the ClinicalTrials.gov (NCT05586087). Results: After the intervention period, the bone indicators demonstrated significant improvements: whole-body BMD (p>0.001; effect size (ES)=-0.29 [-0.43, -0.17]); whole-body BMC (p>0.001; ES=-0.15 [-0.24, -0.07]); and dominant femoral neck BMD (p=0.040; ES=-0.10 [-0.20, -0.01]). No significant difference was found for dominant femoral neck BMC. Conclusions: The results suggest that the HSRT program is an effective and safe exercise approach to improve BMC and BMD in independent older adults.