# EXERCISE INTENSITY AND BONE MASS IN YOUNG WOMEN

> **NIH NIH R01** · STANFORD UNIVERSITY · 1990 · $201,915

## Abstract

This study is an exercise intervention trial for young women.  It
is based on the hypotheses that 1) daily activities can be
expressed as a series of discrete events, each represented by
frequency and intensity terms, 2) that density of any bone reflects
its daily loading history, and 3) that intensity of activity is
more important to bone density than the number of loading cycles.

Women will be randomized to 4 groups: control, high intensity
exercise (weight lifting), low intensity-high repetition exercise
(jogging), and combined jogging and weight lifting, each program
continuing for 5 months.  Total bone mineral and regional bone
densities in 5 anatomic regions (calcaneus, knee, hip, low back,
shoulder) will be measured on entry by dual photon absorptiometry,
and will be repeated on completion of the study.  Average loading
histories for each site will be computed from log books and
exercise records by methods validated previously in our laboratory.
Initial values and changes in total and regional bone mass will be
compared among groups, and correlated with average loading
histories.  Data analysis will permit correlation of initial bone
mass values with pre-exercise loading history, comparison of
changes in bone mass among groups, correlation of changes in bone
densities with computed loading history at each anatomic site, and
independent determination of the stress exponent, "m".

## Key facts

- **NIH application ID:** 3158991
- **Project number:** 5R01AR038941-03
- **Recipient organization:** STANFORD UNIVERSITY
- **SAM.gov UEI:** HJD6G4D6TJY5
- **Principal Investigator:** ROBERT A MARCUS
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1990
- **Award amount:** $201,915
- **Award type:** 5
- **Project period:** 1988-01-01 → 1990-12-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3158991

## Citation

> US National Institutes of Health, RePORTER application 3158991, EXERCISE INTENSITY AND BONE MASS IN YOUNG WOMEN (5R01AR038941-03). Retrieved via MORVS 2026-10-24 from https://api.morvs.ai/grant/nih/3158991. Licensed CC0.

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