Whilst exercise while young positively affects peak bone mass, exercise during adulthood can maintain bone mass and can potentially prevent women from osteoporosis.

In particular, impact exercise that induces high strains at high rates in the bone has been found to promote bone strength.

Research published in November’s BMC Musculoskeletal Disorders, studied how bone changes over time during a 12 month course of exercise.

The aim was to evaluate the association between exercise intensity at 3, 6 and 12 month intervals and changes  in the Bone Mineral Density (BMD) of the femur (thigh bone), during high-impact exercise in premenopausal women.

• The subjects were 35 healthy women (age 35-40 years, average BMI of 25.5). Before the study began they were not participating in impact-type exercises or long-distance running more than three times a week.
• Accelerometers, (portable, cheap, light-weight machines, worn on the waist) were used to continuously measure daily physical activity.
• The subjects were supervised during a 60-minute training workout, consisting of a warm-up period, high-impact training and a cool-down period. The progressive high-impact period included versatile movements, such as step aerobic patterns, stamping, jumping, and running, three times a week for 12 months.
• The programs were modified bimonthly to become progressively more demanding by including higher jumps and drops.
• The participants were also given a home program (10 min daily), which consisted of patterns of exercise similar to those in the supervised sessions.
• The BMD of the femur, and the trochanters (the projections from the femur where the hip and thigh muscles attach), were measured using x-ray absorptiometry and activity data was correlated with changes in bone density.

The researchers from Finland found that the average daily number of high impacts during six months of training was significantly associated with 12-month positive BMD changes at the femoral neck and trochanter area.

These results agreed with many previous studies, in which only five to six months of high-impact exercise were needed to increase BMD in the femoral neck and trochanter and the greatest changes were seen on this time period, than during 12 or 18month interventions.

Lead author Riikka Ahola, suggests these results provide new information for designing optimal and feasible training programs that can prevent bone loss in premenopausal women

Because bone cells adapt to regular loading, one important feature that the researchers recommend is for an exercise program to be progressive. ‘A progressive exercise program sustains overload and the bone adaptation process. ‘

‘Loads should be increased with time to produce a sufficient stimulus. An exercise program that maintains the same loading for many years would stimulate bone formation only during the first months of training.’

During exercise and training the body is stressed and immune responses may be compromised. In last years Proceedings of the Nutrition Society of New Zealand research was published showing that muscles incubated with a kiwi extract displayed a marked increase in maximum force and a significant delay in fatigue onset compared to control muscles. Kiwi extract also had an anti-inflammatory effect and protected muscles from exercise induced oxidative stress.

This week at the American College of Sports Medicine Conference, new research presented from the Oregon Health & Science University, showed people who drank 10.5 ounces of cherry juice twice a day for seven days while training for a long distance run, reported significantly less pain after exercise than those who drank another fruit juice beverage. Traditional NSAIDS (non steroidal anti–inflammatory drugs) can have adverse effects, which may be avoided by using a natural whole food alternative like cherry juice. The researchers suggest the cherries post exercise benefits are likely because of the fruit’s natural anti-inflammation power, attributed to antioxidant compounds called anthocyanins which also give cherries their bright red colour.

Blackcurrant supplementation also suppresses exercise-induced oxidative stress, as reported this month in the American journal of Physiology Regulatory, Integrative and Comparative Physiology. However, as the authors point out exercise-induced oxidative stress is instrumental in achieving the health benefits from regular exercise. Therefore, inappropriate use of fruit-derived products, may counteract the positive effects of exercise. Their findings support the concept that consumption of blackcurrant anthocyanins alleviate oxidative stress, and may, if given at the appropriate amount and time, complement exercise’s ability to enhance immune responsiveness to potential pathogens.

The benefits of fruits don’t stop with immune responses and muscle performances. A further review out in the current issue of Aging Research Review suggests that dried plum, or prunes is the most effective fruit in both preventing and reversing bone loss. In two separate animal models of osteopenia (a mild form of decreased bone density, that doesn’t meet the criteria of osteoporosis), results indicated that dried plum not only protects against but more importantly reverses bone loss. In addition in a 3-month clinical trial the consumption of dried plum daily by postmenopausal women significantly increased various serum markers of bone formation by 6-17%.

These interesting findings will prove useful as new types of functional food ingredient for sports drinks and other foods targeted at strengthening bones, enhancing muscle performance, immune function and overall recovery from exercise.

Look out for a cherry and kiwi flavoured sports drink in a shop near you soon!!