Stronger Bones in 2 Minutes!

Q. I have heard that walking is too low-impact to help strengthen bones. What should I do instead?

A. Women who are regularly active (including those who walk frequently) tend to have better bone mass and a lower risk of fractures than sedentary women. But those who include higher-impact activities in their routine are better off because impact is a more potent way to improve bone density.

This may seem surprising because high-impact exercise has frequently gotten a bad rap. This is why: After previously sedentary women in the ’80s became inspired to run and do high-impact aerobics, many of them got injured. They got hurt because they failed to build up to the challenging workouts properly, didn’t wear proper shoes, or did too much too soon, so their bodies didn’t have time to get strong enough to handle the high-energy workouts. Rather than blame their injuries on the fact that they didn’t train properly (also the fault of ’80s fitness instructors and running coaches who didn’t know any better), injuries were blamed on the impact. So for decades, high-impact exercise had the reputation as being unsafe.

In fact, impact is a good thing for bodies, especially for bones. When bones get a little pounding, the impact produces a shockwave that triggers bone-building cells, or osteoblasts, to get busy. The landing impact of jumping produces a mechanical stimulus on the bone cells that walking, or any other forms of weight-bearing — but low- or non-impact — exercise can’t provide.

The interesting thing is that it takes very little impact to reap results. Studies at the Bone Research Laboratory at Oregon State University in Corvallis found that middle-aged to elderly women who did impact exercises three times a week actually prevented bone loss over a five year period compared to women not on the program. The women who did not include impact in their exercise routines showed bone mass losses of around 4.5 percent during the same time period.

Is impact safe for everyone? It depends. People with arthritis, osteoporosis or a history of bone fracture may need to avoid excess pounding. But most women can safely sneak a little bit of impact into their workouts. But if you’re not doing it already, you need to build up to it. Spend at least 12 weeks gradually adding greater amounts of impact. Here are some options:

• Do faux-jumps.
  Stand and lift your body up and down on your tiptoes. Only, instead of lowering your heels slowly, drop them quickly and let them pound a little on the floor. Follow a standard strength-training regimen: Do 2 to 3 sets of 8 to 15 repetitions.
  
  
• Stomp.
  Start marching in place, then stomp in place. Do this for 30 seconds and build up to two minutes. Both stomping and faux jumps keep your body stationary but allow you to give your bones some impact stimulus.
  
  
• Jump.
  There are many variations of jumping that you can do, from hopscotch-like jumps on one leg, to double-footed jumping such as when jumping rope. Or you can do jumping jacks, jogging in place, or squat jumps (squat and jump vertically then land in a controlled manner.) Aerobics, boot camp, sports-conditioning and kickboxing classes often include jumps as part of the workout. Studies show that you only need to jump for a total of two to 10 minutes a day to improve the bone density in your hips and spine.
  
  
• Play sports.
  Most sports sneak impact in: Volleyball, basketball, tennis and squash are all good examples. Jogging or long runs may not be as beneficial for bones as it would seem. That’s because the prolonged impact may cause a desensitivation of bone cells, meaning that the longer the jumping goes on, the less the effect of the impact (otherwise regular runners would have super-big bones!)
  
  It seems that the stop-start nature of many sports provides a better dose of impact stimulus for bones. Of course, you need to be fit before you take up a sport because the fast twists and turns, or leaps and bursts of speed can be too much for an unfit person. Participate in a general strength and cardio program for at least 12 weeks to build up base levels of strength and stamina. Then find a sport you like and go play!

One caveat is that jumping mostly targets the hips and lower spine—it does not provide bone-boosting benefits to the upper body. So how can you impact the upper bones?

Racket sports are a great way to stimulate arm bones. Studies have shown that tennis and racquetball players tend to have greater bone density in their hitting arm.

You can also lift weights—but they should be heavy enough to provide sufficient resistance to significantly improve strength and stimulate bones. Light weights, such as three- to five- pound dumbbells, probably aren’t enough. Heavier weights cause the muscle to contract with more force, causing them to exert more pull on attached bones. That strong pulling force then stimulates the bone cells.