Response of Bone Turnover Markers and Cytokines to High-Intensity Low-Impact Exercise.
BACKGROUND
Low-impact, high-intensity interval exercise (HIE) was used to investigate the postexercise response in bone turnover markers and cytokines.


METHODS
Twenty-three recreationally active males (21.8 ± 2.4 yr) performed one HIE bout on a cycle ergometer at 90% maximum workload. The total duration of the exercise was 12 min and included six 1-min high-intensity exercise intervals separated by 1-min rest intervals. Blood samples were collected before exercise, 5 min, 1 h, and 24 h after exercise and were analyzed for serum levels of anti- and pro-inflammatory cytokines (interleukin 10 [IL-10], interleukin 6 [IL-6], interleukin 1-alpha [IL-1α], interleukin 1-beta [IL-1β], and tumor necrosis factor alpha [TNF-α]) and markers of bone formation (bone alkaline phosphatase [BAP], osteoprotegerin [OPG]) and resorption (amino-terminal cross-linking propeptide [NTX], receptor activator of NF-κB ligand [RANKL]).


RESULTS
There was a significant (P < 0.05) time effect for all bone turnover markers. Post hoc analysis showed that BAP, OPG, and RANKL significantly increased from baseline to 5 min after exercise (10.9%, 13.5%, and 34.2%, P < 0.05). At 1 h after exercise, only BAP was significantly higher than baseline (9.5%, P = 0.010) and remained higher than baseline at 24 h (10.9%, P = 0.001). NTX was significantly lower than baseline 24 h after exercise (-14.6%, P = 0.046). Significant (P < 0.05) time effects were also observed for IL-1α, IL-1β, IL-6, and TNF-α, with all four significantly increasing 5 min after exercise and returning to baseline levels 1 h after exercise. The postexercise changes in bone formation markers correlated positively with the anti-inflammatory cytokine (IL-10) and negatively with the pro-inflammatory cytokines while NTX correlated positively with a pro-inflammatory cytokine, TNF-α (P < 0.05).


CONCLUSIONS
These results suggest that HIE stimulates a response in bone turnover markers and cytokines and that a correlation exists between immune and skeletal responses to this form of exercise. This type of exercise may benefit individuals for whom high-impact exercise might be contraindicated.
Faculty of Applied Health Sciences, Brock University, St. Catharines, Ontario, CANADA.
Yasmeen A
YA
Mezil
David
D
Allison
Kimberly
K
Kish
David
D
Ditor
Wendy E
WE
Ward
Evangelia
E
Tsiani
Panagiota
P
Klentrou
D000469:Alkaline Phosphatase / Q000097:blood; D015415:Biomarkers / Q000097:blood; D016723:Bone Remodeling / Q000502:physiology*; D024042:Collagen Type I / Q000097:blood; D016207:Cytokines / Q000097:blood*; D015444:Exercise / Q000502:physiology*; D006801:Humans; D008297:Male; D053244:Osteoprotegerin / Q000097:blood; D010455:Peptides / Q000097:blood; D005082:Physical Exertion / Q000502:physiology*; D053245:RANK Ligand / Q000097:blood; D013997:Time Factors; D055815:Young Adult
D015415:Biomarkers; D024042:Collagen Type I; D016207:Cytokines; D053244:Osteoprotegerin; D010455:Peptides; D053245:RANK Ligand; C505688:TNFSF11 protein, human; C052929:collagen type I trimeric cross-linked peptide; D000469:Alkaline Phosphatase