16.50 Exercise and bone density.
Many studies have suggested that there is a link between exercise and healthy bones. Exercise stresses the bones and this causes them to get stronger. One study examined the effect of jumping on the bone density of growing rats.17 Ten rats were assigned to each of three treatments: a 60-centimeter “high jump,” a 30-centimeter “low jump,” and a control group with no jumping. Here are the bone densities (in milligrams per cubic centimeter) after eight weeks of 10 jumps per day.
bone
Group | Bone density (mg/cm3) | |||||||||
Control | 611 | 621 | 614 | 593 | 593 | 653 | 600 | 554 | 603 | 569 |
Low jump | 635 | 605 | 638 | 594 | 599 | 632 | 631 | 588 | 607 | 596 |
High jump | 650 | 622 | 626 | 626 | 631 | 622 | 643 | 674 | 643 | 650 |