Safety. Excess quantities of antioxidants may produce a ‘pro-oxidant’ effect, which is the opposite of what you would take these supplements for. The Australian Institute of Sport recommends that antioxidant vitamin supplements only be taken for a period of a few weeks while the body adjusts to stressful circumstances. Excess vitamin C may promote excess iron absorption, which may not be healthy for everyone.
Fish oils are an excellent source of omega-3 fatty acids, which provide myriad benefits for the body. For strength athletes and bodybuilders, we're most concerned with their anti-inflammatory and antioxidant properties. Intense resistance training can cause microscopic tears in your muscle fibers, leading to muscle damage and inflammation. While some inflammation is desirable, too much can delay the post-exercise recovery process.

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]

Sure, using a more effective workout routine or diet plan will work better/faster than a less effective one. However, even when you’re doing everything just right and you’ve optimized every single major and minor factor to work as quickly and effectively as possible (which I’m going to show you how to do), the simple fact is that you’re still not going to build muscle “fast.”
Unfortunately, it’s hard to significantly increase levels through food alone. That’s where supplementation comes in. For instance, in one 12-week study of resistance-trained individuals, taking HMB in tandem with a high-intensity lifting routine significantly improved muscle strength and size compared to lifting alone. Plus, in the off-chance that you push yourself too hard, HMB helps prevent the effects of overtraining—including muscle loss. 

Creatine is an energy substrate: a small peptide serving as a reservoir for high-energy phosphate groups that can regenerate ATP, the main currency of cellular energy. An increase in creatine intake (through food or supplementation) increases cellular energy stores, promoting the regeneration of ATP in the short term. Stores are limited, however, and glucose or fatty acids are responsible for ATP replenishment over longer durations.
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. 

More specifically, you can expect to end up in the upper half of these ranges ONLY if you are a beginner, younger, and/or have amazing genetics. You can expect to end up in the lower half of these ranges if you are an intermediate or advanced trainee, older, and/or have poor genetics. The average person can expect to end up somewhere in the middle. Additional details here: How Much Muscle Can You Gain?
Longer rest periods are more ideal for making progressive tension overload happen, and shorter rest periods are more ideal for generating metabolic fatigue. So, if you’re doing an exercise that is better suited for progressive overload (i.e. primary compound exercises), you’re going to want to rest longer between sets to maximize strength output. And if you’re doing an exercise that is better suited for metabolic fatigue (i.e. isolation exercises), you’re going to want to rest less between sets to make that happen. And if you’re doing an exercise that is suited equally for a combination of the two (i.e. secondary compound exercises), you’re usually going to want a moderate rest period somewhere in between.
Back in the 1970s, scientists discovered that taking creatine in supplement form might enhance physical performance. In the 1990s, athletes started to catch on, and creatine became a popular sports supplement. The supplement is particularly popular among high school, college, and professional athletes, especially football and hockey players, wrestlers, and gymnasts. 
There are many camps within the weight training fitness community. We have bodybuilders, Crossfit athletes, powerlifters, Olympic lifters, and strongman athletes just to name the most popular ones off the top of my head. One thing they all have in common is that they all use resistance to achieve a particular goal. They all also “share” particular exercises. Most resistance-training athletes do barbell squats, overhead presses and deadlifts. I can write pages of differences between each of the disciplines I listed above and I can also write quite a bit about their similarities but one form of resistance training is MORE different than the others. Bodybuilding is the only sport that judges the appearance of the athlete rather than their performance. This may be why bodybuilders tend to get poked at the most.
Age-related muscle loss: Many different dosing regimens have been used; however, most use a short-term “loading dose” followed by a long-term maintenance dose. Loading doses are typically 20 grams daily for 4-7 days. Maintenance doses are typically 2-10 grams daily. Older adults seem to only experience benefits from creatine supplementation when it is combined with resistance training.
Each serving of Optimum Nutrition Creatine supplies a full 5 grams (5000 mg) of 99.9% pure Creapure brand Creatine Monohydrate. The patented production method used to produce this Creatine yields a tasteless, odorless powder that mixes easily into water or juice and does not readily settle to the bottom. As a result, the gritty taste or texture you may have experienced with other Creatine powders is not associated with this product. Keep Reading »

Entry into neural tissues in general is mediated by the secondary creatine transporter (CrT-2) known as SLC6A10,[186] which is the same transporter that is active in a male’s testicles.[145] CrT-2 belongs to the family of SLC6 transporters that act to move solutes across the membrane by coupling transport with sodium and chloride.[187][188] Genetic deletions in the 16p11.2 region, which encodes both SLC6A8[189] and SLC6A10[186] can result in severe mental retardation in humans and is one of the causes of “Creatine Deficiency Syndrome.” Creatine Deficiency Syndrome is not only caused by lack creatine transporter expression, however, as creatine synthesis is also critical for neural function.[190].[189] Retardation caused by defective creatine synthesis[31] can be reversed with creatine supplementation and dietary changes.[191]
Overload: The first thing you need to do to build lean muscle tissue is use more resistance than your muscles are used to. This is important because the more you do, the more your body is capable of doing, so you should increase your workload to avoid plateaus. In plain language, this means you should be lifting enough weight that you can only complete the desired number of reps. You should be able to finish your last rep with difficulty, but also with good form.
Creatine supplementation appears to augment the anti-cancer effects of Vitamin C and methylglyoxal,[463] a metabolic by-product of glycolysis.[464] Methylglycoxal appears to inhibit step 1 of the electron transport chain in isolated mitochondria and cancerous mitochondria, but has not been implicated in doing so in normal tissue, as protective measures in normal cells appear to exist.[465][464]
Creatine is mostly synthesized in the liver via AGAT and GAMT[28][32] (the other locations are neurons,[34] the pancreas, and kidneys[33]) despite it not being stored in high levels in the liver like glycogen or adipose would be. Supplemental creatine is known to suppress AGAT by downregulating transcription,[30] which probably occurs in humans (since the products of AGAT are reduced with creatine supplementation).[38]
Creatine is not an essential nutrient[19] as it is naturally produced in the human body from the amino acids glycine and arginine, with an additional requirement for methionine to catalyze the transformation of guanidinoacetate to creatine. In the first step of the biosynthesis these two amino acids are combined by the enzyme arginine:glycine amidinotransferase (AGAT, EC: to form guanidinoacetate, which is then methylated by guanidinoacetate N-methyltransferase (GAMT, EC:, using S-adenosyl methionine as the methyl donor. Creatine itself can be phosphorylated by creatine kinase to form phosphocreatine, which is used as an energy buffer in skeletal muscles and the brain.

While there are many reasons why an individual might have weak glute muscles, one of the main causes is that many of us are living increasingly sedentary lifestyles. Many jobs now involve people sitting down for a big part of their day, or after a long day of work we go home and sit on the couch; this means that the gluteus muscles can become dormant more than they should be. Another reason why someone might have weak glutes could be because of poor form and generally over-relying on other muscles during everyday movements, which contributes further to the muscles remaining inactive. 
So, one way to make the soreness go away, at least temporarily, is to continue exercising.  This increases blood flow to the muscles and helps them heal.  However, remember that we still need them to heal. So if you’re sore from heavy squats, don’t turn around and do heavy squats again. Try doing squats with no weight or yoga/stretching to help bring the soreness down.

Homocysteine is produced after S-adenosyl methionine is used up (as donating a methyl group creates S-adenosylhomocysteine, which then produces homocysteine) mostly from phosphatidylcholine synthesis[307] and its reduction (via either methylation from trimethylglycine via betaine:homocysteine methyltransferase, urinary excretion, or convertion into L-cysteine via cystathionine beta-synthase[308]) is thought to be therapeutic for cardiovascular diseases.

This is why I never understand why girls who don’t want to “get bulky” are told by trainers to do 3 sets of 10-12 (or 5 sets of 1,000 reps of bicep curls with a 1 lb pink dumbbell). While it’s difficult for women to gain any sort of size lifting in ANY rep range, if we were trying to gain muscle size, that’s EXACTLY what we would want to do (as it would be causing sarcoplasmic hypertrophy).
Creatine is known to occur in highly concetrated levels in chicken photoreceptors, relative to other parts of the eye (10-15mM[466]) alongside high levels of creatine kinase.[466] The creatine transporter in human eyes also seems to be concentrated in the photoreceptors,[468] which are known to be susceptible to hypoxic cellular death[471][472] which, for humans, usually means retinal detachment.[473]