4 research outputs found
SPATIAL, TEMPORAL, AND KINETIC VARIABLES DURING THE EARLY ACCELERATION PHASE OF SPRINTING
This study evaluated the relationships between spatial, temporal, and kinetic variables and velocity during the early acceleration phase of sprinting. Ten women and ten men performed sprints across two force platforms. Pearson’s and partial correlation coefficients removing the effect of sex were used to assess relationships between step and sprint velocity during the first four steps and a variety of variables. Significant (p ≤ 0.05) correlations and partial correlations were found between overall sprinting velocity and subject height, countermovement jump, average horizontal force, vertical force, H:V force, stride frequency, foot contact duration and step distance. During the acceleration phase of sprint training, it may be important to liberalize step length after the first two steps. A variety of other recommendations are made
SEX-BASED ANALYSIS OF SPRINT ACCELERATION
This study assessed a variety of kinetic, spatial, and temporal variables during the early acceleration phase of sprinting for both men and women (N = 20) during standing and sprinter position starts. Forces, step distance, time, and velocity measured from the first four steps of each start via force platforms were compared across start, step, and sex via ANCOVA while removing the effect of height or weight. Velocity increased from step 1 to steps 2 and 3; while overall velocity was lower for women and the standing start (p \u3c 0.05). There were interactions of start * sex for horizontal force, ratio of horizontal to vertical force, overall velocity, and overall time (p \u3c 0.05). Men’s performance tended to be more negatively affected when using the standing start than women’s performance
Associations of obesity and circulating insulin and glucose with breast cancer risk: a Mendelian randomization analysis.
BACKGROUND: In addition to the established association between general obesity and breast cancer risk, central obesity and circulating fasting insulin and glucose have been linked to the development of this common malignancy. Findings from previous studies, however, have been inconsistent, and the nature of the associations is unclear. METHODS: We conducted Mendelian randomization analyses to evaluate the association of breast cancer risk, using genetic instruments, with fasting insulin, fasting glucose, 2-h glucose, body mass index (BMI) and BMI-adjusted waist-hip-ratio (WHRadj BMI). We first confirmed the association of these instruments with type 2 diabetes risk in a large diabetes genome-wide association study consortium. We then investigated their associations with breast cancer risk using individual-level data obtained from 98 842 cases and 83 464 controls of European descent in the Breast Cancer Association Consortium. RESULTS: All sets of instruments were associated with risk of type 2 diabetes. Associations with breast cancer risk were found for genetically predicted fasting insulin [odds ratio (OR) = 1.71 per standard deviation (SD) increase, 95% confidence interval (CI) = 1.26-2.31, p = 5.09 × 10-4], 2-h glucose (OR = 1.80 per SD increase, 95% CI = 1.3 0-2.49, p = 4.02 × 10-4), BMI (OR = 0.70 per 5-unit increase, 95% CI = 0.65-0.76, p = 5.05 × 10-19) and WHRadj BMI (OR = 0.85, 95% CI = 0.79-0.91, p = 9.22 × 10-6). Stratified analyses showed that genetically predicted fasting insulin was more closely related to risk of estrogen-receptor [ER]-positive cancer, whereas the associations with instruments of 2-h glucose, BMI and WHRadj BMI were consistent regardless of age, menopausal status, estrogen receptor status and family history of breast cancer. CONCLUSIONS: We confirmed the previously reported inverse association of genetically predicted BMI with breast cancer risk, and showed a positive association of genetically predicted fasting insulin and 2-h glucose and an inverse association of WHRadj BMI with breast cancer risk. Our study suggests that genetically determined obesity and glucose/insulin-related traits have an important role in the aetiology of breast cancer
Associations of obesity and circulating insulin and glucose with breast cancer risk: a Mendelian randomization analysis
BACKGROUND: In addition to the established association between general obesity and breast cancer risk, central obesity and circulating fasting insulin and glucose have been linked to the development of this common malignancy. Findings from previous studies, however, have been inconsistent, and the nature of the associations is unclear. METHODS: We conducted Mendelian randomization analyses to evaluate the association of breast cancer risk, using genetic instruments, with fasting insulin, fasting glucose, 2-h glucose, body mass index (BMI) and BMI-adjusted waist-hip-ratio (WHRadj BMI). We first confirmed the association of these instruments with type 2 diabetes risk in a large diabetes genome-wide association study consortium. We then investigated their associations with breast cancer risk using individual-level data obtained from 98 842 cases and 83 464 controls of European descent in the Breast Cancer Association Consortium. RESULTS: All sets of instruments were associated with risk of type 2 diabetes. Associations with breast cancer risk were found for genetically predicted fasting insulin [odds ratio (OR) = 1.71 per standard deviation (SD) increase, 95% confidence interval (CI) = 1.26-2.31, p = 5.09 x 10-4], 2-h glucose (OR = 1.80 per SD increase, 95% CI = 1.3 0-2.49, p = 4.02 x 10-4), BMI (OR = 0.70 per 5-unit increase, 95% CI = 0.65-0.76, p = 5.05 x 10-19) and WHRadj BMI (OR = 0.85, 95% CI = 0.79-0.91, p = 9.22 x 10-6). Stratified analyses showed that genetically predicted fasting insulin was more closely related to risk of estrogen-receptor [ER]-positive cancer, whereas the associations with instruments of 2-h glucose, BMI and WHRadj BMI were consistent regardless of age, menopausal status, estrogen receptor status and family history of breast cancer. CONCLUSIONS: We confirmed the previously reported inverse association of genetically predicted BMI with breast cancer risk, and showed a positive association of genetically predicted fasting insulin and 2-h glucose and an inverse association of WHRadj BMI with breast cancer risk. Our study suggests that genetically determined obesity and glucose/insulin-related traits have an important role in the aetiology of breast cancer