Effect of kettlebell training on bone mineral density in two older adults with osteoporosis: a multiple-case study from the BELL trial

The purpose of this explanatory retrospective case study was to report clinically significant increases in bone mineral density in a female and a male over 70 years of age with osteoporosis, following 16 weeks of hardstyle kettlebell training. Both case subjects were insufficiently active prior to participating in the BELL trial. Subjects trained five days a week accruing a large training load volume (calculated as kettlebell mass multiplied by repetitions performed) during structured group-based classes (74,872 kg and 110,132 kg, respectively). Regional dual-energy X-ray absorptiometry was used to assess BMD at the hip and lumbar spine. Increases in BMD of 12.7% and 5.9% at the femoral neck and lumbar spine (L2-L4) respectively were observed for the female, and 2.5% and 6.0% respectively for the male. Magnitude of change in BMD (g/cm2) at the lumbar spine was 2.0 and 1.9 times larger than the least significant change for the female and male respectively, and sufficient to advance the female subjects status from osteoporosis to osteopenia. Although these results do not show a definitive causal relationship between kettlebell training and increased BMD, further investigation of the effects of kettlebell training on BMD in older adults with osteoporosis and osteopenia is warranted.