Young people have an even amount of fast and slow twitch fibers regardless of their exercise patterns. Fast twitch fibers disappear as we age. But the weight lifters still had hefty fast twitch fibers in their muscle architecture. The results here are discussing men, who are not plagued with the estrogen deficient bones of menopause. Ladies, head to the gym.
Cigarettes inhibit bone manufacture.
Osteoporosis is not a given. You can control your life. A TMA tissue test will tell you for sure. It will also tell you what to eat and what not to eat to solve your biochemical imbalances.