Saturday, September 22, 2007

Explosive reps - more benefits

Explosive reps....thrusters!

In previous posts we have mentioned some of the benefits of explosive reps - there are for example indications that they could be better for promoting fat loss and are also better at developing power.

A new study identifies a further potential benefit of explosive reps. It seems that they are better at maintaining bone mineral density in older women who trained. A few days ago we thought about training for old age. If you want to maintain your bone health it appears that there may be some advantages then in performing your exercises explosively!

Differential effects of strength versus power training on bone mineral density in postmenopausal women: a 2-year longitudinal study

Objectives: To investigate the effect of two different schemes of loading in resistance training on bone mineral density (BMD) and pain in pretrained postmenopausal women.

Methods: 53 pretrained women (mean (SD) age 58.2 (3.7) years) who carried out a mixed resistance and gymnastics programme were randomly assigned to a strength training (ST) or power training (PT) group. The difference between the two groups was the movement velocity during the resistance training (ST, 4 s (concentric)/4 s (eccentric); PT, explosive/4 s). Otherwise both groups carried out periodised progressive resistance training (10–12 exercises, 2–4 sets, 4–12 repetitions at 70–92.5% of the one-repetition maximum (2/week) for 2 years. Mechanical loading was determined with a force measuring plate during the leg press exercise. At baseline and after 2 years, BMD was measured at different sites with dual x-ray absorptiometry. Pain was assessed by questionnaire.

Results: Loading magnitude, loading/unloading rate, loading amplitude and loading frequency differed significantly (p<0.001) between the two groups. After 2 years, significant between-group differences were detected for BMD (PT, –0.3%; ST, –2.4%; p<0.05) and bone area (PT, 0.4%; ST, –0.9%; p<0.05) at the lumbar spine. At the hip, there was a non-significant trend in favour of the PT group. Also the incidence of pain indicators at the lumbar spine was more favourable in the PT group.

Conclusion: The results show that PT may be superior for maintaining BMD in postmenopausal women. Furthermore, PT was safe as it did not lead to increased injury or pain.

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