Impact of astaxanthin on health and performance among firefighters

INTERVENTION: Randomized Latin Square Design Crossover study given 12mg astaxanthin for 4 weeks, 2 weeks washout then 4 weeks placebo OR placebo for 4 weeks, 2 weeks washout then 4 weeks 12mg astaxanthin. CONDITION: Cardiovascular health and athletic performance ; Not Applicable SECONDARY OUTCOME: ; 1. Fasting blood whole blood cell count (e.g., white blood cell count, red blood cell count, hemoglobin, hematocrit, mean corpuscular volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, red blood cell distribution width, neutrophils, lymphocytes, monocytes, eosinophils, basophils, platelets), liver function markers (e.g., alkaline phosphatase, aspartate transaminase, alanine transaminase, total protein, albumin, globulin, albumin/globulin ratio, bilirubin), and renal function markers (e.g., glucose, sodium, potassium, chloride, carbon dioxide, calcium, blood urea nitrogen, creatinine, blood urea nitrogen/creatinine ratio, non‐African American estimated glomerular filtration rate) were measured to assess clinical health and safety pre‐ and post‐exercise following 28 days of supplementation with astaxanthin or placebo.; 2. Body fat percentage was measured using a dual x‐ray absorptiometry scan following 28 days of supplementation with astaxanthin or placebo.; 3. Height and weight were measured using a Health‐O‐Meter Professional 500KL self‐calibrating digital scale following 28 days of supplementation with astaxanthin or placebo. Furthermore, height and weight were used to calculate body mass inde Xfollowing 28 days of supplementation with astaxanthin or placebo.; 4. Resting heart rate and blood pressure measurements were assessed via an automatic blood pressure monitor following 28 days of supplementation with astaxanthin or placebo.; 5. Subjective stress was measured using the firefighter self‐efficacy coping questionnaire following 28 days of supplementation with astaxanthin or placebo.; 6. Perceived adverse effects were measured via the side effects questionnaire following 28 days of supplementation with astaxanthin or placebo.; PRIMARY OUTCOME: ; 1. Fasting blood advanced oxidation protein products, advanced glycated end products, and adiponectin were measured to assess oxidative stress via enzyme‐linked immunosorbent assays following 28 days of supplementation with astaxanthin or placebo.; 2. Fasting blood granulocyte‐macrophage colony‐stimulating factor [GM‐CSF], interferon‐gamma [IFN‐?], tumor necrosis factor‐alpha [TNF‐a], Interleukin[IL]‐1ß, IL‐2, IL‐4, IL‐5, IL‐6, IL‐8, and IL‐10 were measured to assess inflammation via Luminex multiplex assays pre‐ and post‐exercise following 28 days of supplementation with astaxanthin or placebo.; 3. Fasting blood lipids profiles (i.e., total cholesterol, high‐density lipoprotein, low‐density lipoprotein, non‐high‐density lipoprotein cholesterol, very‐low‐density lipoprotein cholesterol, low‐density lipoprotein / high‐density lipoprotein ratio, total cholesterol/ high‐density lipoprotein ratio, and triglycerides) were measured to assess cardiometabolic health status pre‐ and post‐exercise following 28 days of supplementation with astaxanthin or placebo.; 4. Ventilatory anaerobic threshold, peak oxygen consumption, substrate oxidation rates, and time‐to‐exhaustion were measured to assess cardiorespiratory fitness by analyzing breath‐by‐breath volumes of oxygen consumption and carbon dioxide production on an incremental exercise stress test with a metabolic cart following 28 days of supplementation with astaxanthin or placebo.; 5. Salivary cortisol, uric acid, and interleukin‐1ß were measured to assess the inflammatory and oxidative stress response to firefighter activities via enzyme‐linked immunosorbent assays on post‐supplementation salivary samples collected at pre‐ and post‐firefighter‐specific task assessment. The time points collected were 30 minutes and 5 minutes prior to the firefighter assessment, as well as 5 minutes and 3 minutes after the firefighter assessment following 28 days of supplementation with astaxanthin or placebo.; 6. Time to complete, heart rate responses, and air utilization were measured to assess occupational performance before, during, and after the firefighter activities. Time to completion on the firefighter task assessment was noted as the total time it took to complete the battery of tasks; heart rate responses for the firefighter assessment were taken before, average during, and after the assessment; air utilization was assessed after the assessment by measuring pre‐ and post‐assessment air tank pounds per square inch measurements following 28 days of supplementation with astaxanthin or placebo.; INCLUSION CRITERIA: 1. They have a willingness to provide voluntary, written, informed consent to participate in the study; 2. They are healthy professional or volunteer male firefighters age 18 ‐ 60 years; 3. They are free from any signs, symptoms, or diagnosis of any cardio‐respiratory and/or metabolic disorders; 4. They are free from any known blood disorders (e.g., anemia, hemophilia); 5. They are free from any caffeinated supplements (e.g., thermogenics, pre‐workouts, energy drinks, etc) consumption 24‐hours prior to all testing sessions; 6. They are free from any alcohol and/or nicotine consumption 24‐hours prior to all testing sessions; 7. They are free from ergogenic aids like creatine or testosterone boosters for at least two weeks prior to the initiation of the study; 8. They are resistance trained defined as participating in regular resistance training exercises for at least twice per week for the last si Xmonths;