Of course, cardio is an important part of fitness too, but the benefits of strength training are major. Strength training helps build muscle, and lean muscle is better at burning calories when the body is at rest, which is important whether you're trying to lose weight or maintain it. It also helps strengthens joints and bones, avoid injury, improve your muscular endurance, and will help you give it your all during your other workouts, whether that means setting a new PR if you're a runner or pushing (and pulling) a little harder with your legs during your favorite indoor cycling class.
Deldicque et al  found a 250%, 45% and 70% increase for collagen mRNA, glucose transporter 4 (GLUT4) and Myosin heavy chain IIA, respectively after 5 days creatine loading protocol (21 g/d). The authors speculated that creatine in addition to a single bout of resistance training can favor an anabolic environment by inducing changes in gene expression after only 5 days of supplementation.
The rise in testosterone levels during competition predicted aggression in males but not in females. Subjects who interacted with hand guns and an experimental game showed rise in testosterone and aggression. Natural selection might have evolved males to be more sensitive to competitive and status challenge situations and that the interacting roles of testosterone are the essential ingredient for aggressive behaviour in these situations. Testosterone produces aggression by activating subcortical areas in the brain, which may also be inhibited or suppressed by social norms or familial situations while still manifesting in diverse intensities and ways through thoughts, anger, verbal aggression, competition, dominance and physical violence. Testosterone mediates attraction to cruel and violent cues in men by promoting extended viewing of violent stimuli. Testosterone specific structural brain characteristic can predict aggressive behaviour in individuals.