Endocrinology is the study of human hormones. Hormones can be both incredibly beneficial to our progress in the gym but at the same time, highly detrimental. When your stressed your body releases a hormone called cortisol. Cortisol is a highly catabolic hormone which can significatly affect your weightloss efforts, and your muscle gaining efforts. The less stressful you are the more SUCCESSFUL you will be in your training. Here's the problem. Ironically weight training is actually a catabolic activity, it breaks down your muscles so you can repair from the workout and become a bigger stronger version of your previous self. To counter this catabolism aim to consume some some quick digesting carbs before during and after your workout, this will shift you into a anabolic phase which is prime for muscle building!