Jonathan P R Scott1, Craig Sale, Julie P Greeves, Anna Casey, John Dutton, William D Fraser. 1. Human Sciences (J.P.R.S., A.C.), QinetiQ Ltd, Farnborough GU14 0LX, United Kingdom; Biomedical, Life, and Health Sciences Research Centre (C.S.), School of Science and Technology, Nottingham Trent University, NG1 4BU Nottingham, United Kingdom; Department of Occupational Medicine (J.P.G.), Headquarters Army Recruiting and Training Division, Upavon SN9 6BE, Wiltshire, United Kingdom; Department of Musculoskeletal Biology (J.D.), University of Liverpool, Liverpool L69 7ZX, United Kingdom; and Norwich Medical School (W.D.F.), University of East Anglia, Norwich NR4 7TJ United Kingdom.
Abstract
CONTEXT: Lower PTH concentrations reported in the hours after acute, endurance exercise compared with preexercise levels might be influenced by factors such as circadian fluctuations. OBJECTIVE: The objective of the study was to compare postexercise PTH concentrations with a nonexercising control group. DESIGN AND SETTING: A laboratory-based study with a crossover design, comparing a 60-minute (at 10:30 am) bout of treadmill running at 65% of the maximal rate of oxygen uptake (exercise) with semirecumbent rest (CON). Blood samples were obtained immediately before (baseline 10:15 am) and after (11:30 am) exercise and during recovery (12:30 am, 1:30 pm, and 2:15 pm). PARTICIPANTS: Ten physically active men (mean ± 1 SD, age 26 ± 5 y; body mass 78.3 ± 5.8 kg; maximal rate of oxygen uptake 57.3 ± 6.9 mL/kg(-1) · min(-1)) participated in the study. MAIN OUTCOME MEASURES: PTH, albumin-adjusted calcium, and phosphate concentrations were measured. RESULTS: PTH concentrations increased (+85%, P < .01) during exercise and were higher than in CON immediately at the end of exercise (4.5 ± 1.9 vs 2.6 ± 0.9 pmol/L(-1), P < .05). In the postexercise period (12:30-2:15 pm), PTH was not different compared with baseline but was lower compared with CON at 1:30 pm (-22%; P < .01) and tended to be lower at both 12:30 pm (-12%; P = .063) and 2:15 pm (-13%; P = .057). Exercise did not significantly affect the albumin-adjusted calcium concentrations, whereas phosphate was higher than CON immediately after exercise (1.47 ± 0.17 vs 1.03 ± 0.17 pmol/L(-1), P < .001) and was lower at 1:30 pm (-16%: P < .05). CONCLUSIONS: Lower PTH concentrations after acute endurance running compared with a rested control condition suggest a true effect of exercise.
CONTEXT: Lower PTH concentrations reported in the hours after acute, endurance exercise compared with preexercise levels might be influenced by factors such as circadian fluctuations. OBJECTIVE: The objective of the study was to compare postexercise PTH concentrations with a nonexercising control group. DESIGN AND SETTING: A laboratory-based study with a crossover design, comparing a 60-minute (at 10:30 am) bout of treadmill running at 65% of the maximal rate of oxygen uptake (exercise) with semirecumbent rest (CON). Blood samples were obtained immediately before (baseline 10:15 am) and after (11:30 am) exercise and during recovery (12:30 am, 1:30 pm, and 2:15 pm). PARTICIPANTS: Ten physically active men (mean ± 1 SD, age 26 ± 5 y; body mass 78.3 ± 5.8 kg; maximal rate of oxygen uptake 57.3 ± 6.9 mL/kg(-1) · min(-1)) participated in the study. MAIN OUTCOME MEASURES: PTH, albumin-adjusted calcium, and phosphate concentrations were measured. RESULTS: PTH concentrations increased (+85%, P < .01) during exercise and were higher than in CON immediately at the end of exercise (4.5 ± 1.9 vs 2.6 ± 0.9 pmol/L(-1), P < .05). In the postexercise period (12:30-2:15 pm), PTH was not different compared with baseline but was lower compared with CON at 1:30 pm (-22%; P < .01) and tended to be lower at both 12:30 pm (-12%; P = .063) and 2:15 pm (-13%; P = .057). Exercise did not significantly affect the albumin-adjusted calcium concentrations, whereas phosphate was higher than CON immediately after exercise (1.47 ± 0.17 vs 1.03 ± 0.17 pmol/L(-1), P < .001) and was lower at 1:30 pm (-16%: P < .05). CONCLUSIONS: Lower PTH concentrations after acute endurance running compared with a rested control condition suggest a true effect of exercise.
Authors: Wendy M Kohrt; Pamela Wolfe; Vanessa D Sherk; Sarah J Wherry; Toby Wellington; Edward L Melanson; Christine M Swanson; Connie M Weaver; Rebecca S Boxer Journal: Med Sci Sports Exerc Date: 2019-10 Impact factor: 5.411