If you want to build strength and endurance simultaneously, combine interval training and weight training.
High-intensity interval training (HIIT) includes repetitions of short bouts of high-intensity workout followed by short rest. Endurance training interferes with strength training because it activates different biochemical pathways resulting in improvements in either endurance or strength or endurance. HIIT is very intense and may not interfere with strength gains.
British researchers discovered that combining HIIT with resistance exercise activated the mTOR pathway and suppressed myostatin, which leads to accelerated protein synthesis. Combining HIIT and weight training in a single workout is a good way to build strength and endurance simultaneously.