The effects of 10 weeks military training on heel ultrasound and bone turnover.
To measure the physiological changes in bone in response to strenuous exercise we performed a prospective study of male army recruits over 10 weeks of basic training. Measurements performed at the start and completion of training consisted of ultrasound (US) measurements of the heel: velocity of sound (VOS in m/seconds) and broadband ultrasound attenuation (BUA in dB/MHz) and bone turnover markers; osteocalcin (OC), bone-specific alkaline phosphatase (BALP), and tartrate-resistant acid phosphatase (TRAP). Forty subjects were recruited for the study and 26 completed training. Over the 10-week study period there was a significant 1.7% fall in mean VOS [mean paired difference (mpd) 27.2 m/second, SEM 9.5 (95% CI 7.5-46.8) P = 0.009] and a nonsignificant 3.4% increase in BUA (P = 0.159). There were significant falls in markers of bone formation OC [11.6%, mpd 0. 11 microg/liter (95% CI 0.07-0.14) P < 0.001] and BALP [13.3%, mpd 3. 49 U/liter (CI 0.80-6.18) P = 0.013] and a nonsignificant 9.5% fall in TRAP a marker of bone resorption. The 10 recruits subsequently injured had a significantly lower VOS on entry [mean difference 24.2 m/seconds (95% CI 4.6-43.7) P = 0.017] and nonsignificantly raised BUA and baseline levels of all bone markers. The ultrasound changes may be accounted for by increase in trabecular separation and a fall in trabecular connectivity due to microfracture. The decrease in bone markers implies a fall in bone turnover.
Etherington
J
J
Defence Medical Services Rehabilitation Centre, Headley Court, Epsom, Surrey, KT18 6JN UK.
Keeling
J
J
Bramley
R
R
Swaminathan
R
R
McCurdie
I
I
Spector
T D
TD
D000135:Acid Phosphatase / Q000097:blood; D000328:Adult; D000469:Alkaline Phosphatase / Q000097:blood; D015415:Biomarkers / Q000097:blood; D016723:Bone Remodeling / Q000502:physiology*; D002111:Calcaneus / Q000000981:diagnostic imaging* / Q000502:physiology*; D015444:Exercise / Q000502:physiology*; D006801:Humans; D007527:Isoenzymes / Q000097:blood; D008297:Male; D008889:Military Personnel; D015675:Osteocalcin / Q000097:blood; D011446:Prospective Studies; D000071681:Tartrate-Resistant Acid Phosphatase; D014463:Ultrasonography
D015415:Biomarkers; D007527:Isoenzymes; D015675:Osteocalcin; D000469:Alkaline Phosphatase; D000135:Acid Phosphatase; D000071681:Tartrate-Resistant Acid Phosphatase