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INCREASED PHYSICAL ACTIVITY IS ASSOCIATED WITH ENHANCED DEVELOPMENT OF PEAK BONE MASS IN MEN: A FIVE- YEAR LONGITUDINAL STUDY. Nilsson M, Ohlsson C, et al. Journal of Bone and Mineral Research 2012;27(5):1206–1214

A standardised self-administered questionnaire was used to collect information from 833 men aged 24.1 ± 0.6 years of age, who were asked about patterns of physical activity at baseline and at a 5-year follow-up. Bone mineral content (BMC) and volumetric bone mineral density, (vBMD) were measured using dual energy X-ray absorptiometry, and vBMD, areal bone mineral density (aBMD) and bone geometry were measured by peripheral quantitative computed tomography. Increased physical activity between the baseline

and follow-up visits was associated with a favourable development in BMC of the total body and aBMD of the

lumbar spine and total hip, as well as with development of a larger cortical cross sectional area and a denser trabecular bone of the tibia.

sportEX comment

During the Olympics and in the reams of newsprint issued since there has been much talk about the Games generating interest in sport. The bottom line here is that bone is healthier following physical activity and in the long term is expected to lead to less risk of osteoporosis later in life. So there are lots of reasons to get out there and do a bit.

HYDRATION, SWEAT AND THERMOREGULATORY RESPONSES TO PROFESSIONAL FOOTBALL TRAINING IN THE HEAT. Duffielda R, McCallb A, et al. Journal of Sports Sciences 2012;30(10):957–965

Thirteen professional football players completed three training sessions graded as; “higher-intensity” for 140 min (HI); “lower-intensity” for 120 min (LI); and “game-simulation” for 100 min (GS). Movement demands were measured by global positioning system; sweat rate and sweat concentration were determined from dermal patches and body-mass change. All took place in similar environmental conditions of 26.9 ± 0.1°C and 65.0 ± 7.0% relative humidity. Higher relative speeds

increased perceptions of effort and thermal strain plus a significantly greater sweat rate and electrolyte losses were observed in HI and GS compared with LI. The results showed that the rate of rise in core temperature, session rating of perceived exertion, loss of potassium (K+) sweat rate, and total sweat loss could be predicted using mean speeds, whereas the strongest predictor of sodium (Na+) and K+ losses was the total distance covered.

sportEX comment This is a study that states

the obvious. Work harder in the sun and you get hot and sweaty. The conditions are one of the excuses used whenever the British Home Nations fail at yet another summer football tournament, but now science has proved it happens there is no excuse for not preparing properly. Now if only science could help the English take penalties we might win once in a while.

EMG OF THE HIP ADDUCTOR MUSCLES IN SIX CLINICAL EXAMINATION TESTS. Lovell GA, Blanch PD, Barnes CJ. Physical Therapy in Sport 2012;13(3):134–140

The test group was composed of 21 male athletes from an elite junior soccer programme. Bilateral surface EMG recordings of the adductor magnus, adductor longus, gracilis and pectineus were taken along with unilateral fine-wire EMG of the pectineus during isometric holds in six clinical examination tests. A load cell was used to measure force data. EMG activation was highest with

the hips at 0° or 45° for adductor magnus, adductor longus and gracilis.

For pectineus, it was was highest with the hips at 90°. Injury history was a significant factor in the EMG output for the adductor longus, pectineus, and gracilis) but not adductor magnus. For force data, clinical test type was a significant factor with hips at 0° being significantly stronger than with the hips at 45°, 90° and in side lying. Body mass index (BMI) was a significant factor for producing a higher force. All other factors had no significant effect on the force outputs.

sportEX comment There are two important

factors here. The first is that if you are looking for an adductor lesion, test in more than one position up to 90° if you want to separate out pectineus. The second factor is that previous injury resulted in a significant fall in the EMG outputs. Is this because previous rehab wasn’t taken to the very end of the healing process which may be up to 18 months post-injury? Moral of the story is don’t stop rehab at return to play.

4 sportEX dynamics 2012;34(October):4-6