Carbohydrates play an important role for bodybuilders. They give the body energy to deal with the rigors of training and recovery. Carbohydrates also promote secretion of insulin, a hormone enabling cells to get the glucose they need. Insulin also carries amino acids into cells and promotes protein synthesis. Insulin has steroid-like effects in terms of muscle gains. It is impossible to promote protein synthesis without the existence of insulin, which means that without ingesting carbohydrates or protein—which also induces the release of insulin—it is impossible to add muscle mass. Bodybuilders seek out low-glycemic polysaccharides and other slowly digesting carbohydrates, which release energy in a more stable fashion than high-glycemic sugars and starches. This is important as high-glycemic carbohydrates cause a sharp insulin response, which places the body in a state where it is likely to store additional food energy as fat. However, bodybuilders frequently do ingest some quickly digesting sugars (often in form of pure dextrose or maltodextrin) just before, during, and/or just after a workout. This may help to replenish glycogen stored within the muscle, and to stimulate muscle protein synthesis.
Major variants: incline ~ (more emphasis on the upper pectorals), decline ~ (more emphasis on the lower pectorals), narrow grip ~ (more emphasis on the triceps), push-up (face down using the body weight), neck press (with the bar over the neck, to isolate the pectorals), vertical dips (using parallel dip bars) or horizontal dips (using two benches with arms on the near bench and feet on the far bench, and dropping the buttocks to the floor and pushing back up.)
It's never too late to start. In one study of elderly men and women (mean age 87) who lifted weights three times per week for 10 weeks, strength increased a whopping 113%! The improvement in strength enabled the elderly participants to also walk faster (12% faster than before the study), climb 28% more stairs, and it even caused the muscles in their thighs to increase by more than 2.5%.
The squat is performed by squatting down with a weight held across the upper back under neck and standing up straight again. This is a compound exercise that also involves the glutes (buttocks) and, to a lesser extent, the hamstrings, calves, and the lower back. Lifting belts are sometimes used to help support the lower back. The freeweight squat is one of 'The Big Three' powerlifting exercises, along with the deadlift and the bench press.
After session 12, consider whether you need to increase the weight for any particular exercise. If you can comfortably do more than the RM of 12 exercises, increase the weight by a modest amount, say two pounds or a kilogram for isolation exercise muscles such as triceps and biceps, and 5 pounds or 2.5.kilograms for compound and large muscle group exercises like squats and deadlifts. When using dumbbells, this would apply to each one. Don’t increase the number of sets beyond 3 at this time.