Body mass index associations between mother and offspring from birth to age 18: the Fels Longitudinal Study.

BACKGROUND: Parental obesity is a known determinant of childhood obesity. Previous research has shown a strong maternal influence on body mass index (BMI) during infancy and early childhood. OBJECTIVES: The purpose of this research was to investigate the BMI associations between mother and offspring from birth to age 18 years. METHODS: Participants were selected from the Fels Longitudinal Study. The current study sample includes 427 (215 mother/son and 212 mother/daughter) mother/child pairs. These pairs are repeatedly measured at multiple age groups in children, resulting in a total of 6,263 (3,215 mother/son, 3,048 mother/daughter) observations for data analysis. Inclusion criteria were children with measured height and weight for BMI collected at ages 0 to 18 years and their mother with BMI data. Maternal influences of BMI on offspring BMI from birth to early adulthood were analyzed by Spearman correlations and linear regression analyses. RESULTS: Mother/son BMI correlations became statistically significant (p ≤ 0.05) at age 5-6 years and were significant through puberty and into early adulthood at age 18 years. Mother/daughter correlations became significant at age 1.5 years and also continued through adolescence, puberty and early adulthood at age 18 years. Associations persisted after the study sample was grouped into life stages and adjusted for decade of birth and parity. CONCLUSIONS: The mother/daughter relationship was more strongly correlated than the mother/son relationship and also became statistically significant at an earlier age than boys.

Modeling a two-mile run age and body weight handicap for men and women.

PURPOSE: To develop a weight and age handicap model for Two-Mile Run Test (2MRT) performance for adult men and women using dimensional analysis and recent empirical data. METHODS: Models of the body composition- and physical activity-adjusted effect of age on VO2max and the allometric model of body size and 5 K run time for men and women (adjusted for the 2MRT distance) were employed. RESULTS: Two tables were developed, one for each gender. Each provides a simple index (sec) of run time based on body weight and age, that are subtracted from actual 2MRT time to yield adjusted run time. CONCLUSION: Such a handicap model, which grants a handicap based only on the independent effects of age and weight (not fatness or lack of physical conditioning, for example), is the first to be based on physiologically sound theory and empirical data. It may prove useful for military fitness testing particularly in situations where higher achievement is rewarded and/or control for age and weight differences in warranted.

Exercise does not change high-density lipoprotein cholesterol in women after ten weeks of training.

Effects of a 10 wk, three times per wk individualized bicycle ergometer training program were investigated in 16 healthy sedentary women 19-29 yr-old who were not taking oral contraceptives or other medications. Twelve women were in an interval type program, 6 in a continuous program, all performing 30 min exercise per session at 70% maximum heart rate reserve. Conditioning responses did not differ between the training regimens. Training produced increases in maximum oxygen uptake and physical work capacity. Percent body fat determined by underwater weighing was significantly reduced as was resting heart rate, after the training program. Maximum heart rate was unchanged. Despite changes in "fitness" variables, post-training values of high density lipoprotein cholesterol and triglycerides did not differ from pretraining. High-density lipoprotein cholesterol was significantly reduced at 2 and 5 wk of training and returned to control levels at 10 wk. Exercise conditioning leading to improved physical fitness in healthy women may not be associated with increments in high density lipoprotein cholesterol levels.

Wheelchair exercise performance of the young, middle-aged, and elderly.

The purpose of this study was to quantitate the maximal power output (POmax), peak oxygen uptake (peak VO2), and maximal heart rate (HRmax) for wheelchair ergometer (WERG) exercise performed by three groups of disabled males: young adult (20-30 yr), middle-aged (50-60 yr), and elderly (80-90 yr). These subjects, who were confined to wheelchairs for similar time periods (mean = 11.7 yr), participated in progressive-intensity discontinuous test protocols on a WERG. Lower (P less than 0.01) mean POmax, peak VO2, and HRmax values were found with advancing age groups. In relationship to age, decreases in POmax and HRmax values were best described by parabolic models, whereas decreases in peak VO2 values were best described by a linear model. In comparison with young adults (83 W, 27 ml . kg-1 . min-1), surprisingly low POmax and peak VO2 values were found for the middle-aged (16 W, 10 ml . kg-1 . min-1) and elderly (7 W, 8 ml . kg-1 . min-1). When our peak VO2 data were combined with other data in the literature for upper body exercise by male disabled individuals, a decrease of 0.19 1 . min-1 or 2.9 ml . kg-1 . min-1 per decade of life was found.

Anthropometry of aged male wheelchair-dependent patients.

A number of anthropometric dimensions, including stature, weight, circumferences, estimated body fat from skinfolds and handgrip strength were measured on a sample of 33 male wheelchair-dependent Veterans Administration patient-members. These patients had a mean age of 71.2 years, had been wheelchair-dependent for a mean of 5.2 years and had various physical disabilities. When the anthropometric dimensions for these wheelchair-dependent patients were compared to those previously reported for ambulatory veterans of similar age, we found similar statures, total body fat percentages, and limb circumferences. In contrast, the wheelchair-dependent individuals tended to have smaller upper body skinfolds, and greater body weight, trunk circumferences, lower body skinfolds and handgrip strength. These differences may be due in part of the biomechanics of wheelchair locomotion and the rather sedentary lifestyle of many wheelchair users.

Effect of a controlled exercise program on serum lipoprotein levels in women on oral contraceptives.

The effects of a 10-wk individualized bicycle ergometer interval training program were investigated in a group of 13 sedentary women on a specific oral contraceptive (50 micrograms mestranol, 1 mg norethisterone) to determine if, like men on physical training, their high-density lipoprotein cholesterol levels would increase. Six additional women on the oral contraceptive served as a nonexercising control group. All subjects were between 18 and 30 yr and were nonsmokers. Diet and alcohol intake were stable throughout the study period, and were monitored throughout. The interval training program was three times per week, 30-min exercise per session, at 70% maximum heart rate reserve (resting heart rate + 0.7 x [maximum heart rate-resting heart rate]). Training produced increases (p < 0.05) in maximum oxygen uptake. Body weight was unchanged. However, unlike similar training programs with males, there were no significant changes in plasma high-density lipoprotein cholesterol or triglycerides. In women receiving estrogen progestin oral contraceptives, consistent exercise programs may fail to elevate high density lipoprotein cholesterol levels, consistent with an interaction of sex hormone-exercise effects and/or with the less marked effect of exercise on high-density lipoprotein cholesterol in women.

PIP: The effects of a 10 week individualized bicycle ergometer interval training program were investigated in a group of 13 sedentary women on a specific (OC) oral contraceptive (50 mg mestranol, 1 mg norethisterone) to determine if, like men on physical training, their (HDL) high-density lipoprotein cholesterol levels would increase. 6 additional women on OCs served as a nonexercising control group. All subjects were between 18 and 30 years and were nonsmokers. Diet and alcohol intake were stable throughout the study period, and were monitored throughout. The interval training program was 3 times/week, 30 minutes exercise/session, at 70% maximum heart rate reserve (resting heart rate + 0.7 x [maximum heart rate-resting heart rate]). Training produced increases (p0.05) in maximum oxygen uptake. Body weight was unchanged. However, unlike similar training programs with males, there were no significant changes in plasma HDL cholesterol or triglycerides. In women receiving estrogen progestin OCs, consistent exercise programs may fail to elevate HDL cholesterol levels, consistent with an interaction of sex hormone-exercise effects and/or with the less marked effect of exercise on HDL cholesterol in women.

Metabolic and cardiopulmonary responses to wheelchair and bicycle ergometry.

To evaluate wheelchair activity in reference to a more familiar mode of locomotion, metabolic and cardiopulmonary responses to wheelchair ergometer (WERG) and bicycle ergometer (BERG) exercise were compared. Eighteen able-bodies subjects were tested on a combination wheelchair-bicycle ergometer. Oxygen uptake (VO2), respiratory exchange ratio (R), pulmonary ventilation (VE), ventilatory equivalent (VE/VO2), percent net mechanical efficiency (ME), and heart rate (HR) were determined at power output (PO) levels of 30, 90, and 150 kpm/min on each ergometer. For WERG and BERG exercise, VO2, VE, and HR increased linearly with PO. Generally, VO2, R, VE, VE/VO2, and HR responses were higher (P less than 0.05) during WERG than BERG exercise at each PO. Blood lactate was determined after 150 kpm/min, and found to be higher (P less than 0.05) during WERG than BERG exercise. ME increased with PO and was lower (P less than 0.05) for WERG than BERG exercise at each PO level. The greater metabolic and cardiopulmonary responses observed during WERG exercise may be due to inefficient biomechanics and the relatively small upper body musculature used for propulsion.

An exercise test to evaluate fitness for wheelchair activity.

The purpose of this study was to develop a wheelchair ergometer (WERG) test to evaluate fitness for manual wheelchair activity. Thirty able-bodied females participated in a progressive intensity, discontinuous test where exercise bouts were 4 min in duration interspersed with 5-min rest periods. Physiological responses of oxygen uptake (VO2), respiratory exchange ratio (R), net mechanical efficiency (ME), pulmonary ventilation (VO) and heart rate (HR) were determined during the final minute of exercise at power output (PO) levels of 30, 60, 90, 120 and 150 kpm/min. These responses were generally found to be linearly related to PO, however, net ME initially increased with PO and plateaued at approximately 11 per cent at 90 kpm/min. Criteria for fitness evaluation were based upon: (1) magnitude of physiological responses at each PO level; and (2) the maximal PO level completed.

Comparative muscular strength of men and women: a review of the literature.

The results from nine separate studies reporting comparable static and dynamic muscle strength measurements between men and women have been reviewed. The statistical data from these studies are presented in graphical and tabular form illustrating, when appropriate, the mean +/- 1 S.D., and the mean percentage difference between men and women for the given measurement.

Arm-reach capability of USAF pilots as affected by personal protective equipment.

Thirty-two USAF pilots participated in a study to determine the effects of personal protective equipment upon arm-reach capability. The reach envelope of each pilot was measured under two experimental conditions: 1) shirt-sleeved with the inertial reel unlocked; and 2) wearing complete winter flying assembly with the inertial reel locked. Selected descriptive statistics are presented for each of five angular positions. Arm-reach envelopes for various percentile values obtained for the two experimental conditions at 10 knob distances from the deck are shown. The results indicate that there are singificant practical differences in arm-reach capability between the shirt-sleeved and the complete winter flying assembly conditions.