Available at: http://digitalcommons.calpoly.edu/theses/1637
Date of Award
MS in Kinesiology
Alison K. Ventura
Current options for maintaining or slowing aging-related bone mineral density (BMD) loss in postmenopausal women primarily include pharmaceutical agents. More recently, physical activity and exercise have been suggested as highly effective, low cost alternatives. Weighted aerobic exercise, utilizing load carriage systems (LCS), is known to increase the gravitational forces impacting bone, creating a higher osteogenic stimulus than standard aerobic exercise. In response to the positive research on aerobic exercise with well-designed LCS, Dr. Lawrence Petrakis, MD, developed a unique 5.44 kg uniformly weighted exercise suit. This study aimed to examine the effects of the uniformly weighted exercise suit on serum biochemical markers of bone formation (Amino- Propeptide of Type 1 Collagen [P1NP]; Carboxy-Terminal Propeptide of Type 1 Collagen [P1CP] and resorption (Carboxy-Terminal Telopeptide of Type 1 Collagen [CTX]) in response to submaximal aerobic exercise in postmenopausal women with low bone density. Nine volunteer, sedentary to lightly active, healthy postmenopausal women (Age: 58.7±1.1 years, BMI: 28.2±1.0, BMD T-score: -1.2±0.5) participated in this within-subjects study, wherein each participant exercised under two counterbalanced conditions (aerobic exercise with [ES] or without [NS] the exercise suit). During each condition, participants walked on a treadmill at 65%-75% of their age-predicted maximum heart rate until they reached their goal caloric expenditure (400kcal). There was a seven-day washout period between sessions. Serum was processed using ELISA protocols to investigate the change in biomarker at 24 and 72 hours post exercise, relative to baseline. The results indicated, when compared to the NS condition, the ES condition elicited a greater positive change in P1CP at 24 hours (Phours following exercise (P0.05). There was no effect of condition on P1NP at any time point (P>0.05). In sum, submaximal aerobic exercise while wearing the uniformly weighted exercise suit elicited an antiresorptive effect on bone collagen resorption with a simultaneous increase in bone collagen formation 24 hours post exercise.