• Effect of pomegranate juice consumption on biochemical parameters and complete blood count

      Manthou, Eirini; Georgakouli, Kalliopi; Deli, Chariklia; Sotiropoulos, Aggelos; Fatouros, Ioannis; Kouretas, Dimitrios; Haroutounian, Serko; Matthaiou, Chrysoula; Koutedakis, Yiannis; Jamurtas, Athanasios; et al. (Spandidos Publications, 2017-06-27)
      Pomegranate has been used therapeutically for centuries. The aim of the present study was to examine the effects of pomegranate juice (PJ) supplementation on complete blood count (CBC), glucose, blood lipids and C‑reactive protein (CRP) in healthy subjects. A total of 5 males and 5 females (aged 31.8±6.6 years, weighing 66.2±12.9 kg) were randomly assigned into one of two groups and either consumed 500 ml PJ/day or no PJ for 14 days. Blood samples were obtained from participants prior to and following the experimental period. PJ consumption resulted in a significant increase in red blood cell count (P<0.05), hemoglobin levels (P<0.001) and hematocrit levels (P<0.05). Other CBC parameters, glucose, cholesterol, triglycerides, high‑density lipoprotein, low‑density lipoprotein and CRP levels did not significantly change following PJ consumption. These results indicate that PJ intake for a short period of time may result in increased erythropoiesis or decreased degradation without any significant alterations in factors associated with metabolic health and inflammation in healthy individuals.
    • Plyometric exercise increases serum indices of muscle damage and collagen breakdown.

      Tofas, Trifon; Jamurtas, Athanasios Z; Fatouros, Ioannis; Nikolaidis, Michalis G; Koutedakis, Yiannis; Sinouris, Efstathios A; Papageorgakopoulou, Nickoletta; Theocharis, Dimitrios A (Human Kinetics Publishers, Inc., 2008)
      The aim of the present study was to examine the effect of acute plyometric exercise on indices of muscle damage and collagen breakdown. Nine untrained men performed an intense bout of plyometric jumping exercises (experimental group) and nine men remained at rest (control group). Seven days before and 24, 48, and 72 hours after plyometric exercise or rest, several physiological and biochemical indices of muscle damage and two biochemical indices of collagen damage were determined. No significant changes in concentric and eccentric peak torque of knee extensors and flexors or flexion and extension range of motion were found after the plyometric exercise. Delayed-onset muscle soreness increased 48 hours after exercise. Creatine kinase increased 48 and 72 hours post exercise, whereas lactate dehydrogenase increased 24, 48, and 72 hours post exercise. Serum hydroxyproline increased 24 hours post exercise, peaked at 48 hours, and remained elevated up to 72 hours post exercise. Hydroxylysine (which was measured only before exercise and at 48 hours) was found increased 48 hours post exercise. No differences were found in any physiological or biochemical index in the control group. Intense plyometric exercise increased muscle damage, delayed-onset muscle soreness, and serum indices of collagen breakdown without a concomitant decrease in the functional capacity of muscles. Hydroxyproline and hydroxylysine levels in serum seem promising measures for describing exercise-induced collagen degradation. Coaches need to keep in mind that by using plyometric activities, despite the increased muscle damage and collagen turnover that follow, it is not necessarily accompanied by decreases in skeletal muscle capacity.
    • Uniform and prolonged changes in blood oxidative stress after muscle-damaging exercise

      Paschalis, Vassilis; Nikolaidis, Michalis G.; Fatouros, Ioannis; Giakas, Giannis; Koutedakis, Yiannis; Karatzaferi, Christina; Kouretas, Dimitris; Jamurtas, Athanasios Z. (International Institute of Anticancer Research, 2007)
      Background: The effect of eccentic exercise on the time-course changes in several indices of muscle damage and blood oxidative stress as examined. Materials and methods: Isometric rorque, delayed-onset muscle soreness, creatine kinase, reduced glutathione (GSH), oxidized glutathione (GSSG), thiobarbituric-acid reactive substances (TBARS), protein carbonyls, catalase, uric acid, bilirubin and total antioxidant capacity (TAC) in blood were measured pre-, 24 h, 48 h and 72 h post-exercise of knee extensors in ten females. Results: The concentration of all oxidative stress indices changed significantly in a way indicating increased oxidative stress in the blood (GSH and GSH/GSSG, decreased, whereas GSSG, TBARS, protein carbonyls, catalase, uric acid, bilirubin and TAC increased) peaking, in all but TBARS, at 48 h and returning towards baseline afterwards. Conclusion: We believe that muscle-damaging exercise should be viewedd as a different challenge compared to non-muscle-damaging exercise with regard to its effects on blood oxidative stress.