Cycling Nutrition with Monique Ryan: Building bone density, part 2

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We received quite a few questions in response to Building Bone Density, which looked at some recent data in professional and highly training amateur cyclists in regards to their risk for developing osteopenia or osteoporosis. Please see these answers below.

Does riding my mountain bike help?

Hi Monique,
Great article. I’m curious primarily as a road cyclist who does some trail riding as well. Are there any studies out there on cyclists who do both or just trail? Hard to imagine that the constant vibration on the trail would not be stimulating a lot of osteoblastic activity in the spine, pelvis, and legs.

Thanks,
— KS

Any data on mountain bikers? Seems like this might be an easy way for the road cyclist to get some impact and do useful cross-training.
— SM

KS and SM,
Currently there is limited data comparing the bone health benefits of road cycling to mountain biking. One study published in the journal “Bone” has compared the bone mineral density of three groups: roadies, mountain bikers, and a recreationally trained control group. DEXA was used to measure the bone density of the femur, lumbar spine, and total body. When data was adjusted for body weight and controlled for age, bone mineral density was significantly higher at all sites in the mountain bikers when compared with the road cyclists and recreationally trained controls. The researchers concluded that road cycling was not any more beneficial to bone health than recreational activity in healthy men. The higher bone density in the mountain bikers also suggests that this type of cycling training may provide an osteogenic stimulus that is not inherent to road cycling.

However, this is only one study. Even if you put in the trail miles, it is recommended that you still complete some type of weight bearing exercise twice weekly, year round.
— Monique

What is the best exercise for bone health?

Monique,
That was a really good article about bone density. I am the perfect case study of this problem. I am a 39 year old Cat 2/master. I ride 12,000 miles per year, and have been racing bikes since I was a junior back in 1986. I lift weight s once a week during the season and twice a week in the off season. I managed to get through almost 20 years without serious injury. In 2005 I broke my left collarbone, 2007 I broke my right one, and I broke three ribs in July of this year. I had my orthopedic check my bone density. One hip was on the low side of normal and the other showed signs of osteopenia. I consume a well-balanced diet with plenty of dairy and I take calcium supplements too. I am in the process of working with a specialist. One thing that I was told is that running seems to provide the best impact for bones compared to weight lifting.
— JL

I ride a huge amount and genuinely hate to run. So my question is, how often is the minimum running you would suggest to help combat low bone density? How many times per week (year round) and how far each run?
— PT

JL and PT,
As you are aware, both resistance training and weight-bearing endurance activity are recommended to help preserve bone health during adulthood. One recent study in the “Journal of Strength and Conditioning Research” looked at the effects of long-term running, cycling, and resistance training on total body and specific sites of bone mineral density as measured by DEXA. Long-term running activity and resistance training both increased bone mineral density when compared to cycling. When the researchers calculated further and adjusted for differences in lean body mass between the groups of athletes, it appeared that a high impact activity such as running, could have a greater positive effect on bone mineral density than resistance training.

Clearly both activities offer an advantage to cyclists who have not been focused on adequate resistance training. “Bone grows in response to stress on the bone. This is true whether the load is from weight-bearing exercise such as lifting weights, resistance training or running. There does not need to be impact for bone to grow, just weight bearing. While there is no definitive answer as to how much weight, it is clear that non-weight bearing activity such as swimming will not provide enough stimulus to maintain bone health,” said Michael Ross, MD author of Maximum Performance for Cyclists and director at The Performance Lab, a medical facility which focuses on sports performance, located in the Philadelphia area. “Weight bearing exercise twice weekly should go a long way towards maintaining bone health. I recommend squats, running, rows, or pushups using a stability ball as bone health exercises that would also be good for cycling.”

Study results regarding the benefits of running have varies with some studies showing that while running may positively influence hip bone density, but not the bone density of lumbar spine. “Running at lower intensities may help provide impact to the hip, with the impact starting at the ankle joint and up to the hip, with the spine not receiving enough stimulus for remodeling,” said Aaron Smathers, MS who has studies low bone density in cyclists. “Of course, no research has yet looked at cyclists who had low bone density.”

It might also be helpful to keep in mind that many of these studies on cycling and bone health have looked at pro cyclists or highly trained amateurs. “The life of a pro cyclist revolves around riding for multiple hours. Because of the overwhelming desire to remain lean, there may not be enough calcium or Vitamin D intake and there might not be enough body fat to maintain stores of Vitamin D,” said Dr. Ross.

Though one study published in Medicine & Science in Sport & Exercise did have more “ordinary” cycling subjects. “The majority of subjects were not elite amateurs or top level pros, but mainly Cat 3 and 4 racers. Their body fat percent was normal, “ said Aaron Smathers, MS. “This just drives home the point that anyone that rides competitively or at the level for required for competition should be aware of this problem.”

What other nutritional strategies can improve bone health?

“Exercise is a good way to maintain bone health, however, it may not be the best way to increase bone mineral density. The importance of calcium and vitamin D cannot be overlooked,” said Dr Ross.

“The real question remains as to what mechanism or mechanisms are driving the loss of bone mineral density in the cyclists, or why these cyclists have lower bone mineral density than the control population they were match to for height and weight,” said Smathers. “Although this is speculative, I think it may be a combination of calcium loss in sweat, hormonal disruption, and the non-weight bearing nature of cycling, and no other forms of activity that positively influence bone density.”

There is some other interesting nutrition data coming out that cyclists can consider as part of a comprehensive approach to maintaining bone health. Fruits and vegetables can actually offer a protective effect to your bones by balancing an excess of acid in your body, a condition that can occur as we age. In a recent study published in the “Journal of Clinical Endocrinology and Metabolism” researchers reported that a potassium bicarbonate or sodium bicarbonate supplement helped to reduce bone resorption and calcium excretion that can occur when the body is titled more towards an acidic balance rather than an alkaline one. These results suggest that leaning towards a diet that is more alkaline could help prevent bone loss in healthy older adults.

Eating fruits and vegetables would be expected to have the same effect. When fruits and vegetables are metabolized they add the alkaline compound bicarbonate to the body. Some components of your diet that could increase the acidity of your diet include excessive intake of protein and cereal grains. The typical American diet does contain high amounts of protein and cereal grains in contrast to fruit and vegetable intake.

In another recent study published in the “American Journal of Clinical Nutrition” the natural pigments found in plants, called carotenoids, were found to help protect against bone loss in older men and women. Over a four year period, carotenoid intake, particularly lycopene was associated with some level of decreased bone loss in the hip in men and lumbar spine in women. Carotenoid intake may explain the previously observed protective effects of fruits and vegetables on bone mineral density. There are over 600 different carotenoids in foods, and they are what give plants their red, orange, and yellow coloring from strawberries to carrots to tomato sauce. Carotenoids are also antioxidants and may help protect bone by reducing oxidative stress and decreasing bone breakdown.

In fact, bone loss may also be part of the process of inflammation. The bone cells that break down bone, osteoclasts are influence by pro-inflammatory processes in the body. Conditions that induce excessive inflammatory responses can compromise bone integrity. Focusing in consuming foods and beverages that have an anti-inflammatory effect can also be part of a bone loss prevention strategy.

Anti-inflammatory food components include dry beans and tofu, green tea, fruits and vegetables, fish, nuts, canola and extra virgin olive oil, herbs and spices such as basil, cinnamon, ginger, mint, oregano, thyme. Pro-inflammatory foods include excessive consumption of refined sugar, highly processed carbohydrate, hydrogenated and partially hydrogenated oils, processed meats, and saturated fat.

So, are there any other steps that you can take if you are concerned about bone mass. “Decreasing high volume workouts and replacing them with high-intensity training sessions can also help to decrease the caloric deficiency which can lead to weak bones,” said Dr. Ross.”

Cyclists and especially women over 35 should consider a DEXA scan (a test of bone mineral density) after a fracture or stress fracture.
— Monique

Monique Ryan, MS, RD, LDN is a nationally recognized nutritionist with over 22 years of experience and is owner of Personal Nutrition Designs, a Chicago-based nutrition consulting company that provides nutrition programs for endurance athletes across North America.