Breast volume measurements were made on 47 adult subjects using a casting method. After drying, fast-setting plaster casts were filled with sand of known density to a level approximating the curvature of the chest wall. The reliability of both sand filling and casting proved to be high, r = 0.97, and r = 0.99, respectively. The total variable error was 10.2%. The effects of position (standing versus lying) was investigated in a separate sample of 15 subjects. No significant difference (P less than 0.05) was found between methods. The relationship between breast volume, girths, skinfolds, and body density was reported to be low.

Adolescent↗

PubMedDate not supplied

Validity of the Mellits and Cheek method for body-fat estimation in relation to menstrual cycle status in athletes and non-athletes below 22 per cent fat.

The present experiment tested the hypothesis that 22% body fat based on the Mellits and Cheek (1970) regression equation is a minimum or 'trigger' level of fatness required to maintain regularity of menstrual cycles. The validity of the regression equation was cross-validated against densitometric estimates of body fat in 30 athletes (track, gymnastic, crew) and 30 non-athletes who were below 22% fat. For the total sample, the validity correlation was r = 0.47 between body fat (density) and body fat (regression equation); it was r = 0.75 for athletes and r = 0.47 for non-athletes. For all subjects, 60% had regular menses, 27% were oligomenorrheic and 13% were amenorrheic. The lowest body fat (density) was 12.8% for an athlete with a regular cycle and 12.2% for an oligomenorrheic athlete. The results show that: the Mellits and Cheek (1970) height-weight based regression equation to determine fatness is not valid for women below 22% fat, and 13% body fat (not 22%), should be considered an upper-bound estimate of a minimum level of fatness associated with normal ovulatory cycles.

Adipose Tissue↗

PubMedDate not supplied

Strength training for prepubescent males: is it safe?

This study examined the safety of one type of strength training for prepubescent males. Eighteen males (average age, 8.3 +/- 1.2 years) participated in a 45 min/session, three session/week, 14 week supervised strength training program with an attendance rate of 91.5%. Concentric work was done almost exclusively. KinCom analysis showed significant strength gain in this group (P less than 0.05), while an age, sex, and activity matched control group did not gain strength. Safety was evaluated by injury surveillance, blood pressure and heart rate monitoring, scintigraphy, and creatine phosphokinase measurement. Effects on growth and development, flexibility, and motor performance were also investigated, as these are factors with an impact on sports injury occurrence. Results showed that in the short term, supervised concentric strength training results in a low injury rate and does not adversely affect bone, muscle, or epiphyses; nor does it adversely affect growth, development, flexibility, or motor performance. As the safety question is multifaceted, this should not lead to the conclusion that strength training for prepubescents is uniformly safe. Further research is needed.

Athletic Injuries↗