Related Experiment Video
Updated: Aug 30, 2026

A Simple Pit Assay Protocol to Visualize and Quantify Osteoclastic Resorption In Vitro
Published on: June 16, 2022
The response of a bone resorption marker to marine recruit training
Kathleen M Sheehan1, Michelle M Murphy, Katy Reynolds
1US Army Research Institute of Environmental Medicine, Military Performance Division, 42 Kansas Street, Natick, MA 01760, USA.
Objectives:
This study measured the response of deoxypyridinoline, a biomarker of bone resorption, during 11 weeks of Marine recruit training.
Methods:
Urine samples were obtained from 155 female and 58 male Marine recruits from the first morning void every 3 days during training. Training miles of weight-bearing exercise were recorded daily, and injury data were obtained from the medical clinic staff.
Results:
Deoxypyridinoline was significantly (p < 0.001) increased at week 2 and weeks 9 through 11 for women and at weeks 10 and 11 for men. The increase in bone resorption corresponded to an increase in miles of weight-bearing exercise performed throughout training. The incidence of stress fracture and reaction was 3.9% and 14.8%, respectively, for women and 1.7% and 3.4%, respectively, for men.
Conclusions:
Significant bone resorption took place at the end of Marine recruit training due to accumulation of weight-bearing exercise throughout training and the increase in marching toward the end.
Related Concept Videos
Osteoclasts in Bone Remodeling
Bone Remodeling
The Bone Matrix
Hormones and Bone Tissue
Hormones That Influence Osteoblasts and/or Maintain the Matrix
Several hormones are necessary for controlling bone growth and maintaining the bone matrix. The pituitary gland secretes growth hormone (GH), which, as its name implies, controls bone growth. This happens in several ways: first, it triggers chondrocyte...
Bone Remodeling and Repair
Bone Disorders
Bone deposition is also affected by the levels of sex hormones like estrogen and testosterone that promote osteoblast activity and bone matrix synthesis. When the level of these hormones decreases due to aging, it causes a reduction in bone deposition. As a result, bone resorption by osteoclasts...

