Lippincott, Williams & Wilkins, The Journal of Strength and Conditioning Research, 11(27), p. 3045-3052, 2013
DOI: 10.1519/jsc.0b013e31828bf2c9
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The purpose of this study was to investigate adaptation mechanisms following two test rounds consisting of eccentric exercise using pressure pain imaging of the wrist extensors. Pressure pain thresholds (PPT) were assessed over 12 points forming a 3×4 matrix over the dominant elbow in 12 participants. From the PPT assessments, pressure pain maps were computed. Delayed onset muscle soreness was induced in an initial test round of high intensity eccentric exercise. The second test round performed 7 days later aimed at resulting in adaptation. The PPTs were assessed before, immediately after and 24 hours after the two test rounds of eccentric exercise. For the first test round, the mean PPT was significantly lower 24 hours after exercise compared with before exercise (389.5 ± 64.1 vs. 500.5 ± 66.4 kPa, respectively; p= 0.02). For the second test round, the PPT was similar before and 24 hours after (447.7 ± 51.3 vs. 458.0 ± 73.1 kPa, respectively; p= 1.0). The present study demonstrated adaptive effects of the wrist extensors monitored by pain imaging technique in healthy untrained humans. A lack of hyperalgesia, i.e. no decrease in PPT underlined adaptation after the second test round of eccentric exercise performed 7 days after the initial test round. The present findings showed for the first time that repeated eccentric exercise performed twice over two weeks protect the wrist extensor muscles from developing exacerbated pressure pain sensitivity. Thus, the addition of eccentric components to training regimens should be considered to induce protective adaptation.