IntroductionIn order to reduce cardiovascular disease risk factors, a healthy diet must include dietary antioxidants from different sources (eg,Spirulina maxima) and regular practice of exercise should be promoted. There is some evidence from animal studies thatS. maximaand exercise decrease cardiovascular disease risks factors. However, very few studies have proved the independent or synergistic effect ofS. maximaplus exercise in humans. This study attempts to address the independent and synergistic effects in overweight and obese subjects participating in a systematic physical exercise programme at moderate intensity on general fitness, plasma lipid profile and antioxidant capacity.Methods and analysisUsing a randomised, double-blind, placebo-controlled, counterbalanced crossover study design, 80 healthy overweight and obese subjects will be evaluated during a 12-week isoenergetic diet accompanied by 4.5 g/dayS. maximaintake and/or a physical systematic exercise programme at moderate intensity. Body composition, oxygen uptake, heart rate, capillary blood lactate, plasma concentrations of triacylglycerols, total, low-density and high-density lipoprotein cholesterol, antioxidant status, lipid oxidation, protein carbonyls, superoxide dismutase, catalase, glutathione, glutathione peroxidase, glutathione reductase and paraoxonase will be assessed.Ethics and disseminationThis study and all the procedures have been approved by the Universidad Autonoma de Ciudad Juarez Bioethics Committee. Findings will be disseminated through peer-reviewed journals, national and international conferences.Trial registration numberClinicalTrials.gov:NCT02837666.