Kyröläinen, H, Hackney, AC, Salminen, R, Repola, J, Häkkinen, K, and Haimi, J. Effects of combined strength and endurance training on physical performance and biomarkers of healthy young women. J Strength Cond Res 32(6): 1554-1561, 2018-Cardiovascular fitness has decreased and obesity has increased in young adults worldwide during the last 10 years. Therefore, there is an urgent need to find out optimal exercise training programs for improving physical performance and health outcomes, especially among sedentary women. Subjects were 25- to 30-year-old women with a very low physical activity, and 65% of them were overweight (body mass index > 25). They performed endurance and strength training 3 times a week for 9 weeks. Independent strength training and instructed endurance training by indoor cycling were prescribed. Measurements were performed before, in the middle, and after the training period. No nutritional guidelines were given to the subjects. The 9-week training period led to an 8.5% increase in estimated maximal oxygen uptake. Maximal isometric strength of the leg and arm extensors as well as trunk flexors and extensors increased by 28.9, 7.8, 27.2, and 16.1%, respectively. Total cholesterol values lowered by 7.6%, and high-density lipoprotein increased by 8.8%, whereas low-density lipoprotein, hemoglobin, serum glucose, and triglyceride remained unchanged. Serum cortisol increased by 22.7%, but no changes in plasma testosterone, estradiol, or sex hormone binding globulin were observed. The skeletal muscle mass increased by 0.8% without other changes in body composition. Our results indicated that only 27 combined endurance and strength training sessions in 9 weeks improved maximal endurance and strength capacity as well as some health outcomes. Thus, combined strength and endurance training itself can induce significant health benefits without the necessity of changes in dietary habits.