The term “adrenaline” is commonly used to refer to the body’s excitatory catecholamines, Epinephrine (E) and Norepinephrine (NE), which are regulators of lipolysis (fat breakdown). NE and E acts on receptors called adrenergic receptors of which there are alpha (1 & 2) and beta (1, 2, & 3) subtypes. Activation of the alpha1 and beta-receptors is lipolytic (causes fat breakdown) while activation of the alpha2 receptor is anti-lipolytic (blunts fat breakdown). Stubborn fat areas have a high density of alpha2 receptors, making it harder for fat breakdown to occur in that area. If you are a women this means you have a large amount of alpha2 receptors in your thighs and glutes.
For the first couple weeks, we'll use relatively lighter loads. We'll progress to using heavier loads as we move forward, but for now, don't push yourself beyond where you feel safe. Once you feel comfortable doing the movements and understand how they should feel, then you can start adding a more weight. Take full advantage of our exercise database by clicking on each exercise below for detailed instructions!
Now you may be saying, “I have seen some female bodybuilders who are very muscular and look similar to men in their build.” The real reason they look like that is they are most-likely using exogenous testosterone injections and/or other anabolic steroids. When women use exogenous testosterone/steroids they may show signs of hair growth on the face and chest, increased muscle mass, a redistribution of body fat from a female pattern of storage to a male pattern of storage, deepening of the voice, and other effects. The point of saying this is that unless you are on exogenous testosterone or other anabolic steroids, you will not become big and bulky from lifting weights.
I appreciate such a thorough synthesis on this topic. As a systematic reviewer, my main concern would be a lack of systematic assessment of risk of bias in the individual studies. I see you did a funnel plot to see any bias by study size, but there are so many other things involved in study quality (study design, selection of participants, statistical adjustment for potential con founders, etc). I would be interested to see how many of these studies were fair or better quality (there are several well accepted quality rating tools available for various study designs). I would also be interested to see a sensitivity analysis to see if the pooled results differ when high risk of bias studies are eliminated, for example. Thanks for an interesting read.

This week you're going to continue with the circuit-style sets; this time you'll perform only 12 reps of each movement, but there are two (tough!) changes: You'll complete a total of 4 full circuits (that's four sets of each exercise for both workouts) and there will be no rest in between each circuit. This week is all about keeping you moving! After you finish the last movement of either workout, you'll immediately return to the first movement and begin a new circuit!