The Effect of Eccentric Exercise and Iron Supplementation on Blood Redox Status and Muscle Performance in Different Age Groups
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 28
- 主要终点
- Changes in Creatine kinase, CK (activity IU)
研究概览
简要总结
Iron supplementation is very common in athletes, probably due to its catalytic role on the oxygen transport and optimal function of oxidative enzymes and proteins during exercise.
Iron is also characterized as a potent pro-oxidant, as it can lead to increased production of reactive oxygen and nitrogen species (RONS) that are involved in critical biological processes, such as gene expression, signal transduction and enzyme activity. In exercise, low levels of RONS are essential for optimal force production, whereas excessive production of RONS can cause contractile dysfunction, resulting in muscle weakness and fatigue. On the other hand, RONS are involved in signaling pathways and up-regulation of the expression of several genes, and therefore, RONS can provoke favorable effects such as training adaptations.
The purpose of the present study is to investigate the effect of iron supplementation on redox status, muscle damage and muscle performance after an acute bout of a valid muscle damaging eccentric exercise model in adults and children.
详细描述
Eccentric muscle work is an essential part of human daily activities, such as walking, and in particular, when walking downhill or descending stairs. It is also a component of almost all of the athletic actions. The most notable and well-described effect of eccentric exercise is the muscle damage that peaks one to three days after exercise and is accompanied by several hematological, biochemical and physiological responses. Excessive production of reactive oxygen and nitrogen species (RONS) has been reported as a result of eccentric exercise. The typical approach so far, was to provide antioxidants to minimize oxidative stress, yet the effectiveness of such an approach is still under debate. Earlier studies reported positive effects of antioxidant supplementation on muscle performance, muscle damage and redox status, whereas more recently, well-received studies pointed towards the negative impact of antioxidant supplementation.
Iron is an essential element for the completion of numerous important biological functions, and also for optimal exercise performance. It is a vital component for the formation of oxygen-transport and iron-storage proteins hemoglobin and myoglobin, and for the most favorable function of many oxidative enzymes that affect the intracellular metabolism. Therefore, iron supplementation is commonly used to avoid exercise-induced perturbations of iron homeostasis and maintain the required iron stores that are necessary to address exercise needs or enhance physical performance. Iron is also characterized as a potent pro-oxidant, as it can lead to increased production of reactive oxygen and nitrogen species (RONS) that are involved in critical biological processes, such as gene expression, signal transduction and enzyme activity. Nevertheless, the role of iron on modifying redox responses after eccentric exercise has not yet been examined.
In a double blind, randomized cross over study that will be conducted in two cycles, healthy men and boys will receive either the iron supplement (37mg of elemental iron per day for three weeks before and one week after the eccentric exercise) or the placebo.
Blood samples will be collected: a) in adults prior to, at the end of first supplementation period, 24, 48,72 and 96 hours following an acute bout of eccentric exercise (5 sets x 15 max reps), and b) in children prior to, at the end of first supplementation period and 72 hours following the same exercise protocol. Blood drawings will be repeated at the same time points during the second supplementation cycle.
The aims of the present research are to investigate:
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Crossover
- 盲法
- Double (Participant, Investigator)
入排标准
- 年龄范围
- 10 Years 至 45 Years（Child, Adult）
- 性别
- Male
- 接受健康志愿者
- 是
入选标准
- •Physiological body mass index (BMI).
- •Physiological health profile.
- •Subject provides written informed consent.
排除标准
- •Professional athlete.
- •Consumed any nutritional supplement the last 3 months.
- •Performed pure eccentric exercise the last 6 months.
- •Non Caucasian.
结局指标
主要结局
Changes in Creatine kinase, CK (activity IU)
时间窗: Before the beginning of iron supplementation (baseline), at the end of the first supplementation period (3 weeks: pre exercise), and 72h after the eccentric exercise
CK activity will be measured as a general indicator of muscle damage. Changes in CK activity between baseline and after 3 weeks of supplementation (pre-eccentric exercise), and also between pre-eccentric exercise and 24 hours, 48 hours, 72 hours, 96 hours after the eccentric exercise will be estimated in a Clinical Chemistry Analyzer Z1145 (Zafiropoulos Diagnostica, Athens, Greece) with commercially available kits (Zafiropoulos, Athens, Greece).
Changes in Maximum concentric torque (N.m)
时间窗: Before the beginning of iron supplementation (baseline) at the end of the first supplementation period (3 weeks: pre-eccentric exercise), immediately after the eccentric exercise, and 24 hours, 48 hours, 72 hours, 96 hours after the eccentric exercise
An isokinetic dynamometer (Cybex, Ronkonkoma, NY) will be used for the estimation of changes in isokinetic knee extensor's peak torque at 60o/sec angular velocity between baseline and after 3 weeks of supplementation (pre-eccentric exercise), and also between pre-eccentric exercise and 24 hours, 48 hours, 72 hours, 96 hours after the eccentric exercise. The higher absolute value of five maximal voluntary contractions with the subjects' one lower extremity will be recorded.
Changes in Maximum eccentric torque (N.m)
时间窗: Before the beginning of iron supplementation (baseline) at the end of the first supplementation period (3 weeks: pre-eccentric exercise), immediately after the eccentric exercise, and 24 hours, 48 hours, 72 hours, 96 hours after the eccentric exercise
An isokinetic dynamometer (Cybex, Ronkonkoma, NY) will be used for the estimation of changes in isokinetic knee extensor's peak torque at 60o/sec angular velocity between baseline and after 3 weeks of supplementation (pre-eccentric exercise), and also between pre-eccentric exercise and 24 hours, 48 hours, 72 hours, 96 hours after the eccentric exercise. The higher absolute value of five maximal voluntary contractions with the subjects' one lower extremity will be recorded.
Changes in Range of motion, ROM (degrees)
时间窗: Before the beginning of iron supplementation (baseline) at the end of the first supplementation period (3 weeks: pre-eccentric exercise), immediately after the eccentric exercise, and 24 hours, 48 hours, 72 hours, 96 hours after the eccentric exercise
The assessment of changes in pain-free ROM between baseline and after 3 weeks of supplementation (pre-eccentric exercise), and also between pre-eccentric exercise and 24 hours, 48 hours, 72 hours, 96 hours after the eccentric exercise, will be performed manually using the isokinetic dynamometer. The investigator will move the calf at a very low angular velocity from 0 knee extension to the position where the subject will feel any discomfort.
Changes in Delayed onset muscle soreness, DOMS (scale 1-10)
时间窗: Before the beginning of iron supplementation (baseline) at the end of the first supplementation period (3 weeks: pre-eccentric exercise), immediately after the eccentric exercise, and 24 hours, 48 hours, 72 hours, 96 hours after the eccentric exercise
Each participant will assess changes in delayed onset of muscle soreness (DOMS) during walking and squat movement (90o knee flexion) and perceived soreness between baseline and after 3 weeks of supplementation (pre-eccentric exercise), and also between pre-eccentric exercise and 24 hours, 48 hours, 72 hours, 96 hours after the eccentric exercise. DOMS and perceived soreness will be rated on a scale ranging from 1 (normal) to 10 (very sore).
Changes in Maximum isometric torque (N.m)
时间窗: Before the beginning of iron supplementation (baseline) at the end of the first supplementation period (3 weeks: pre-eccentric exercise), immediately after the eccentric exercise, and 24 hours, 48 hours, 72 hours, 96 hours after the eccentric exercise
An isokinetic dynamometer (Cybex, Ronkonkoma, NY) will be used for the estimation of changes in isometric knee extensor's peak torque at 90o knee flexion between baseline and after 3 weeks of supplementation (pre-eccentric exercise), and also between pre-eccentric exercise and 24 hours, 48 hours, 72 hours, 96 hours after the eccentric exercise. The average of the three best maximal voluntary contractions with the subjects' one lower extremity will be recorded. To ensure that the subjects provide their maximal effort, the measurements will be repeated if the difference between the lower and the higher torque value exceed 10%. There will be two minutes rest between isometric efforts.
次要结局
- Changes in Reduced glutathione, GSH (μmol/g Hb)(Adults: at baseline, pre-eccentric exercise, 24,48,72 & 96 hours after the eccentric exercise. Children: at baseline, pre-eccentric exercise and 72 hours after the eccentric exercise)
- Changes in Protein carbonyls, PC (nmol/mg pr)(Adults: at baseline, pre-eccentric exercise, 24,48,72 & 96 hours after the eccentric exercise. Children: at baseline, pre-eccentric exercise and 72 hours after the eccentric exercise)
- Changes in Transferin saturation (TS) (%)(Adults: at baseline, pre-eccentric exercise, 24,48,72 & 96 hours after the eccentric exercise. Children: at baseline, pre-eccentric exercise and 72 hours after the eccentric exercise)
- Changes in Catalase (μmol/min/mg Hb)(Adults: at baseline, pre-eccentric exercise, 24,48,72 & 96 hours after the eccentric exercise. Children: at baseline, pre-eccentric exercise and 72 hours after the eccentric exercise)
- Changes in Uric acid (μm)(Adults: at baseline, pre-eccentric exercise, 24,48,72 & 96 hours after the eccentric exercise. Children: at baseline, pre-eccentric exercise and 72 hours after the eccentric exercise)
- Changes in Total Iron Binding Capacity (TIBC) (μmol/L)(Adults: at baseline, pre-eccentric exercise, 24,48,72 & 96 hours after the eccentric exercise. Children: at baseline, pre-eccentric exercise and 72 hours after the eccentric exercise)
- Changes in Thiobarbituric acid-reactive substances, TBARS (μM)(Adults: at baseline, pre-eccentric exercise, 24,48,72 & 96 hours after the eccentric exercise. Children: at baseline, pre-eccentric exercise and 72 hours after the eccentric exercise)
- Changes in Iron concentration (mg/dL)(Adults: at baseline, pre-eccentric exercise, 24,48,72 & 96 hours after the eccentric exercise. Children: at baseline, pre-eccentric exercise and 72 hours after the eccentric exercise)
- Changes in Oxidized glutathione, GSSG (μmol/g Hb)(Adults: at baseline, pre-eccentric exercise, 24,48,72 & 96 hours after the eccentric exercise. Children: at baseline, pre-eccentric exercise and 72 hours after the eccentric exercise)
- Changes in Total antioxidant capacity, TAC (mm DPPH)(Adults: at baseline, pre-eccentric exercise, 24,48,72 & 96 hours after the eccentric exercise. Children: at baseline, pre-eccentric exercise and 72 hours after the eccentric exercise)
- Changes in Bilirubin (μM)(Adults: at baseline, pre-eccentric exercise, 24,48,72 & 96 hours after the eccentric exercise. Children: at baseline, pre-eccentric exercise and 72 hours after the eccentric exercise)
- Changes in Ferritin (ng/mL)(Adults: at baseline, pre-eccentric exercise, 24,48,72 & 96 hours after the eccentric exercise. Children: at baseline, pre-eccentric exercise and 72 hours after the eccentric exercise)
研究者
Athanasios Z. Jamurtas
Associate Professor
University of Thessaly