This article is an excerpt from Sports Nutrition for Endurance Athletes by Monique Ryan MS, RD, LDN, CSSD. In her comprehensive guide to sports nutrition, Ryan uses her 30 years of experience coaching professional and age-group athletes to simplify this complex subject into proven, real world guidelines. Sports Nutrition for Endurance Athletes shows runners, cyclists, and triathletes how to address specific nutritional needs for short- and long-course racing and busts dozens of myths and misconceptions along the way.
It has long been known that the proper type of exercise for stimulating production of osteoblasts, the cells that build bone, is weight-bearing activity and weight training. But some endurance sports, such as swimming and cycling, do not offer these specific weight-bearing benefits.
It is not unusual during a full season of racing to hear about a pro cyclist or two breaking a clavicle or other bone in a multirider pileup. But is there something inherent to cycling that increases your risk of developing a break when you hit the pavement hard? A growing body of research indicates that being fit through cycling training alone does not guarantee optimal bone density.
Bad bones are a serious health concern. Osteoporosis is characterized by low bone mass and deterioration of bone tissue over time. This leads to fragile bones and increased risk of fracture of the hip, spine, and wrist. Osteopenia, or subnormal bone density, precedes osteoporosis.
Recent studies should convince cyclists especially to pay attention to training and nutrition strategies that maximize bone mass. A recent study at the University of Oklahoma compared the bone mass of competitive male road cyclists, most in their late twenties to early thirties, with men who exercised recreationally. DEXA bone scans indicated the cyclists had lower bone density in the spine than did controls. About one-fourth of the cyclists had bone density scores classified as osteopenia, while 9 percent had the more severe osteoporosis. Researchers could not relate these results to testosterone levels, a bone-regulating hormone in men, or calcium intake.
Bone Building Tips
- Add weight-bearing exercise such as resistance training or running to your training program year-round if you are a cyclist or swimmer.
- Aim for at least 1,000 mg of calcium daily in foods and portions providing: 300 mg daily: milk, 8 ounces; yogurt, 8 ounces; Swiss cheese, 1 ounce 200 mg daily: cheddar cheese, 1 ounce; colby cheese, 1 ounce; mozzarella, 1 ounce; broccoli, 1 cup cooked; collard greens, 1 cup cooked; bok choy, 1 cup cooked 100 mg daily: cottage cheese, 1 cup; dried beans, 1 cup cooked; orange, 1 large.
- If you cannot consume 1,000 mg daily from food, consider adding fortified products such as calcium-fortified orange juice. Check labels of products consumed regularly, such as recovery drinks and energy bars, for calcium content.
- Add a calcium supplement of 500 mg daily if your food intake is not adequate or if you need higher amounts of calcium due to existing low bone mass.
- Increase intake of food sources of vitamin D, such as fortified milk and fatty fish. Most cyclists can safely soak up 15 minutes of direct sunlight three times weekly to produce vitamin D from sunlight, but consider a supplement during the winter months or year-round. Aim for 800 IU daily.
- A high intake of fruits and vegetables has an alkalizing effect on blood levels, as this helps to keep calcium in bone rather than increasing urine calcium losses.
- Cigarette smoking and excess alcohol intake can negatively affect bone mass.
- Hormone status can affect bone mass. It is established in female athletes that inadequate caloric intake can negatively affect hormone levels; more data are needed on male athletes.
A recent study at the University of Colorado also produced worrisome results. Researchers measured bone density in fourteen competitive male cyclists for one year. Bone mass was found to decrease significantly from the pre-season to off-season in several locations. As a sidebar to their study, one group of cyclists was supplemented with 1,500 milligrams or 250 milligrams of calcium citrate daily. This supplementation did not affect the rate of bone loss between groups, indicating that risk factors other than nutrition played a role. The low impact of cycling exclusively, with no other cross-training, can increase your risk of developing low bone density. One study that compared the bone density of cyclists, runners, and weightlifters found that cyclists had lower bone density than the other two groups. Triathletes have been found to modestly increase bone mass over the season.
See what to eat and when with Sports Nutrition for Endurance Athletes. Ryan demystifies optimum daily nutrition and shows simple steps to make the best decisions about what you eat and drink.