Overdeveloped and tight hip flexors can contribute to lower back pain by causing the pelvis to tilt forward. To counteract this, you must stretch the hip flexors and strengthen the Abdominal muscles. This will reduce pelvic tilt and decrease lower back pain. Strengthening the lower back can also help improve the balance between the muscles of the hip region.
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.[26] Insulin has steroid-like effects in terms of muscle gains.[27] 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.[28] 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.[29]
You see, there is only so much muscle that the human body is capable of building in a given period of time. So, if you supply your body with MORE calories than it’s actually capable of putting towards the process of building new muscle… it’s not going to magically lead to additional muscle being built. It’s just going to lead to additional fat being gained.
When a muscle contracts, it shortens. Take the biceps for example. Without getting too technical, the biceps are attached at the forearm and shoulder. When your biceps contract, they shorten and bring those two points closer together. When you rest, the muscle returns to its normal length, and the two points move farther away. Constantly contracting your biceps over a long period of time would cause them to get shorter, even at rest.

Site enhancement oil, often called "santol" or "synthol" (no relation to the Synthol mouthwash brand), refers to oils injected into muscles to increase the size or change the shape. Some bodybuilders, particularly at the professional level, inject their muscles with such mixtures to mimic the appearance of developed muscle where it may otherwise be disproportionate or lagging.[54] This is known as "fluffing".[55][56] Synthol is 85% oil, 7.5% lidocaine, and 7.5% alcohol.[55] It is not restricted, and many brands are available on the Internet.[57] The use of injected oil to enhance muscle appearance is common among bodybuilders,[58][59] despite the fact that synthol can cause pulmonary embolisms, nerve damage, infections, sclerosing lipogranuloma,[60] stroke,[55] and the formation of oil-filled granulomas, cysts or ulcers in the muscle.[59][61][62] Rare cases might require surgical intervention to avoid further damage to the muscle and/or to prevent loss of life.[63]

Even when glycogen is full and glucose gets stored as fat. This fat can only make us gain IF we keep it their. And most people don’t exercise which keeps fat unused. Sure, fats directly leads to fat gain, but again that doesn’t make us fat unless we keep it their. Weight gain vs fat gain is different. Fat increases before weight does, then overtime it starts to show that fat makes up most of the weight. Same for people with muscle.
(3) Fats make you fat - yes, dietary fats get stored as fat. This is there place to go. Fat from a meal that isn’t used for energy will be stored. But, that doesn’t mean fats make you fat. The only way fats can make one “fat” is if the fat stored from meals STAYS stored. Otherwise, knows as a calorie surplus. In a surplus, there is no time for fat to be used for energy. In a deficit, fat will be used because you “aren’t eating enough” So yes, fats get stored as fat, but only make you fat if you keep them stored.
It has been argued that purposely overtraining for a brief period can be beneficial. One article published by Muscle & Fitness magazine stated that you can "Overtrain for Big Gains". It suggested that if one is planning a restful holiday and does not wish to inhibit their bodybuilding lifestyle too much, they should overtrain before taking the holiday, so the body can recuperate and grow during the prolonged rest period. Overtraining can be used advantageously, as when a bodybuilder is purposely overtrained for a brief period of time to super compensate during a regeneration phase. These are known as "shock micro-cycles" and were a key training technique used by Soviet athletes.[53]