“Chronically elevated cortisol levels can cause weight gain in some people, especially around the abdomen area. … It may sound surprising but training too hard can contribute to high cortisol and actually sabotage your health or weight loss goals.It may be why you are not seeing results from your workouts.” source
I like to keep cardio workouts to 30-45 minutes (shorter bursts for HIIT and Tabata; longer for low intensity steady state “LISS”) and strength/resistance (weight) training to 45 minutes in order to reduce negative impacts of cortisol.