Creatine is thought to improve strength, increase lean muscle mass, and help the muscles recover more quickly during exercise. This muscular boost may help athletes achieve bursts of speed and energy, especially during short bouts of high-intensity activities such as weight lifting or sprinting. However, scientific research on creatine has been mixed. Although some studies have found that it does help improve performance during short periods of athletic activity, there is no evidence that creatine helps with endurance sports. Research also shows that not everyone's muscles respond to creatine; some people who use it see no benefit.
Glycogen synthesis is known to respond directly and positively to cellular swelling. This was demonstrated in an earlier study, during which rat muscle cells were exposed to a hypotonic solution in vitro to induce cell swelling, which increased glycogen synthesis by 75%. In contrast, exposing these same cells to a hypertonic solution hindered glycogen synthesis by 31%. These changes were not due to alterations in glucose uptake, but are blocked by hindering the PI3K/mTOR signaling pathway. It was later noted that stress proteins of the MAPK class (p38 and JNK) as well as heat shock protein 27 (Hsp27) are activated in response to increasing osmolarity. Furthermore, activation of MAPK signaling in skeletal muscle cells is known to induce myocyte differentiation via GSK3β and MEF2 signaling, which can induce muscle cell growth.
Creatine supplementation in the under 18 population has not received a great deal of attention, especially in regards to sports/exercise performance. Despite this, creatine is being supplemented in young, <18 years old, athletes [52,53]. In a 2001 report  conducted on pupils from middle and high school (aged 10 – 18) in Westchester County (USA) 62 of the 1103 pupils surveyed were using creatine. The authors found this concerning for 2 main reasons: firstly, the safety of creatine supplementation is not established for this age group and is therefore not recommended. Secondly, it was speculated that taking creatine would lead on to more dangerous performance enhancing products such as anabolic steroids. It is important to point out that this potential escalation is speculation. Furthermore, a questionnaire was used to determine creatine use amongst this age group and does not necessarily reflect the truth.
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.
There are several ways to enhance the quality of a workout, and some changes can even be made during each rep. “Constant tension should be applied to the last five reps of every working set, meaning, do the first 5-6 reps normal tempo, and the last few reps should be held for at least two seconds at the peak of the contraction,” says Heath. “This allows your muscles to have more time under tension and you work different muscle fibers.” Hold the weight at the top for a maximum pump.
A push–pull workout is a method of arranging a weight training routine so that exercises alternate between push motions and pull motions. A push–pull superset is two complementary segments (one pull/one push) done back-to-back. An example is bench press (push) / bent-over row (pull). Another push–pull technique is to arrange workout routines so that one day involves only push (usually chest, shoulders and triceps) exercises, and an alternate day only pull (usually back and biceps) exercises so the body can get adequate rest.
In otherwise healthy adults subject to leg immobilization for two weeks while taking 20g creatine daily during immobilization and then 5g daily during eight weeks of rehabilitation, it was noted that the creatine group failed to reduce atrophy during the immobilization (10% reduction in cross sectional area and 22-25% reduction in force output) despite preventing a decrease in phosphocreatine, yet experienced a significantly enhanced rate of regrowth and power recovery. A similarly structured and dosed study has also noted greater expression of skeletal muscle, GLUT4 expression, and a 12% increase in muscle phosphocreatine content.
There are several different available forms of creatine: creatine anhydrous which is creatine with the water molecule removed in order to increase the concentration of creatine to a greater amount than that found in CM. Creatine has been manufactured in salt form: creatine pyruvate, creatine citrate, creatine malate, creatine phosphate, magnesium creatine, creatine oroate, Kre Alkalyn (creatine with baking soda). Creatine can also be manufactured in an ester form. Creatine ethyl ester (hydrochloride) is an example of this, as is creatine gluconate which is creatine bound to glucose. Another form is creatine effervescent which is creatine citrate or CM with citric acid and bicarbonate. The citric acid and bicarbonate react to produce an effervescent effect. When mixed with water the creatine separates from its carrier leaving a neutrally charged creatine, allowing it to dissolve to a higher degree in water. Manufacturers claim that creatine effervescent has a longer and more stable life in solution. When di-creatine citrate effervescent was studied  for stability in solution it was found that the di-creatine citrate dissociates to citric acid and creatine in aqueous solutions which in turn forms CM and eventually crystallises out of the solution due to its low solubility. Some of the creatine may also convert to creatinine.