Optimum frequency of exercise for bone health: Randomised controlled trial of a high-impact unilateral intervention

Abstract

Additional Information:• NOTICE: this is the author's version of a work that was accepted for publication in Bone.Changes resulting from the publishing process,

Bone Geometry According to Menstrual Function in Female Endurance Athletes

“…Athletes and controls were excluded if they had been pregnant or lactating in the past 12 months; if they had commenced, ceased or changed hormonal contraception use within the previous 12 months or if they had any medical conditions or were taking medications which were likely to affect bone metabolism. The 88 controls were recruited within the Loughborough community for a previous intervention study, the aim of which was to determine the optimum weekly frequency of exercise to increase bone mass in premenopausal women who do not regularly participate in physical activity (16). Baseline measurements are reported here.…”

“…Baseline measurements are reported here. Controls were screened to exclude individuals who had a body mass index > 30 kg/m 2 , participated in high impact or weight bearing exercise more than 1 h/week, or were not regularly menstruating (< 10-13 menstrual cycles per year) (16).…”

Bone Mineral Density in Female Professional Athletes Involved in Weight Bearing and Non-Weight Bearing Exercises

“…Animal studies have considered loading exercises that are high in magnitude, rapidly applied, dynamic and novel as greater osteogenic stimuli, adding that the duration of the workout is less important once a certain threshold level has been reached [13,30,31]. Furthermore, it has been suggested that the distribution of strain may be more important than its magnitude, as unusual patterns of strain can stimulate an osteogenic response at a lower minimum effective strain (MES) [31][32][33].…”

“…The majority of the researches conducted in this field have focused predominantly on post-menopausal women; studies on premenopausal women, though, remain sparse [4,[12][13][14][15][16][17][18]. Taken as a whole, these studies have revealed that not all exercises are effective in this regard.…”

“…Some of the existing studies have compared the effects of various types of exercises on different athletic populations, suggesting that athletes involved in high-impact sports such as hurdling, volleyball and squash have greater bone density than those involved in lower impact sports including orienteering or skiing [13,[19][20][21][22]. These studies have also linked activities with a relatively high impact component such as jumping alone or in combination with aerobic step exercise to increased BMD values at the hip, adding that high-intensity resistance training can improve BMD values at both hip and spine [19,22,23].…”