Discussion
depression, muscle soreness, fatigue
This study was conducted to examine the effects of dietary CPs intake on physical condition and fitness after unaccustomed exercise in healthy middle-aged individuals. The results showed that muscle soreness and fatigue immediately after the exercise load were alleviated by CPs intake. Moreover, dietary CPs intake affected muscle strength 48 hours post-exercise.Unaccustomed or intense exercise is often accompanied by muscle soreness [The two clinical trials examined the effects of CPs intake on endpoints after strenuous exercise in recreationally active or resistance-trained young males. One article [It is uncertain how dietary CPs intake decreased post-exercise fatigue and subsequent muscle soreness in this clinical trial, but it is worth discussing as below. In the animal model for depression research, we found that intake of CPs significantly prolongs forced swimming time in mice, which is caused by dopamine receptors in part [As for the mechanism underlying increment in muscle strength several factors are considered to contribute: the mass and the properties of skeletal muscle; the activation status of motor nerves; the availability of ATP; and the function of surrounding connective tissues such as the fascia and tendons [CPs are hydrolyzates of gelatin, which is heat-extracted animal collagen. CPs consist of a repeating (glycine (Gly)-X-Y) n amino acid sequence, where X and Y are frequently proline (Pro) and hydroxyproline (Hyp), respectively. Gly accounts for one-third of the composition, and the imino acids, Pro and Hyp, account for one-fifth [