One rat study that compared male and female rats and used a forced swim test (as a measure of serotonergic activity of anti-depressants) found that a sexual dimorphism existed, and females exerted a serotonin-mediated anti-depressant response while male rats did not. It appears that these anti-depressive effects are mediated via the 5-HT1A subset of serotonin receptors, as the antidepressant effects can be abolished by 5-HT1A inhibitors.
It's woooooorkkkkkiiiinnnngggg!!! I've been working out without creatine for over a year and a half now and have been missing that extra boost at the end of a set of reps. Not anymore! Started to feel the creatine help out in my 4th workout since using this stuff. It's good, real good. Creatine is one of those only supplements that have actually been proven to increase strength and bursts of endurance at the end of a set, and it's that one thing that can turn a regular workout into something that you're proud of. Just buy it, it works, you won't be disappointed. Use 2 of their servings sizes though, you need 5mg not 2.5. No spoon in bag, you'll need a measuring cup. Mixes effortlessly in juice.
Unfortunately, some people are intolerant to milk, due to the casein (one of the proteins in dairy) and have trouble digesting the sugar in milk, called lactose. If this is the case, stick to whey-only protein shakes. Maximuscle uses Biomax Whey True Protein - a unique blend of whey proteins including whey protein concentrate, isolate and hydrolysate, which are lower in lactose. Biomax Whey True Protein is used in a number of Maximuscle products (Promax and Cyclone).
Spero Karas, MD, assistant professor of orthopaedics in the division of sports medicine at Emory University, says that testosterone, the male hormone responsible for muscle growth, maxes out between the ages of 16 and 18. It reaches a plateau during the 20s and then begins to decline. As a result, muscle building after the adolescent years can be challenging, he says.
Stand on one foot with the arch and heel hanging off of the edge of a step or platform. Hold onto something if you need help balancing. Drop your heel all the way down below the step, and then rise all the way up on your toes. Hold dumbbells to make it harder. If you can balance without holding on to something, you’ll work your core muscles, too. You'll also build more stable joints in the other leg.
JAK2 (Janus-Activating Kinase 2) is a novel protein that has been shown to suppress the activity of the creatine transporter CrT in vitro. The effects of JAK2 on CrT are not well-understood in vivo, however. Given that growth hormone activates both c-src (increases CrT activity) and JAK2- which has been found to decrease CrT activity, it is plausible that JAK2 may function as a negative-feedback regulator of creatine uptake. Future research is needed to better understand the role of JAK2 on CrT activity in vivo.
Similarly to complex training, contrast loading relies upon the enhanced activation of the nervous system and increased muscle fibre recruitment from the heavy set, to allow the lighter set to be performed more powerfully. Such a physiological effect is commonly referred to as post-activation potentiation, or the PAP effect. Contrast loading can effectively demonstrate the PAP effect: if a light weight is lifted, and then a heavy weight is lifted, and then the same light weight is lifted again, then the light weight will feel lighter the second time it has been lifted. This is due to the enhanced PAP effect which occurs as a result of the heavy lift being utilised in the subsequent lighter lift; thus making the weight feel lighter and allowing the lift to be performed more powerfully.
A proper warm-up is an important part of an effective strength workout. Start by foam rolling your muscles to wake 'em up. "Foam rolling loosens up tight muscles so that they work the way they're designed to," says Davis. A dynamic warm-up is another important part of your pre-workout routine, it preps your muscles for the work they're about to do and helps increase your range of motion. Increasing your range of motion allows you to go deeper into those squats and fully extend those bicep curls, which means more muscle recruitment and better results. "These two combined reduce your risk of injury and allow you to push harder during your workout," says Davis. Get started with this five-minute warm-up.
1. Train each muscle group twice per week. To maximize muscle growth, plan to train every major muscle group at least twice per week. According to a 2016 Sports Medicine review, even if you don't work that muscle any harder or longer, by simply dividing your chest, leg or back workout into two days, you'll spur more muscle growth. While the jury is still out on whether training each muscle group three days per week is better than two at spurring hypertrophy, it is likely better suited toward experienced lifters than beginners, Matheny says.
Listen, I know in the beginning of this post I was sympathetic to your problem, but I am also here to say, Suck It Up. I can tell you that to gain weight, you need to focus on making your meals a habit rather than an afterthought. Your body is pre-programmed with your genetic disposition. And in your case, you have a very fast metabolism that digests and burns calories quickly. Focus on having 5-6 calorie-dense meals a day spaced 2-3 hours apart so that your body is constantly being provided with something to metabolize and build muscle.
Beach muscles and Olympic lifts draw more attention. But the many little stabilizer muscles around your shoulders, hips, and midsection — collectively the core — provide a strong foundation. Challenging the stability and mobility of these key muscles with medicine balls, physioballs, mini-bands, and rotational movements (lifting, chopping) pays huge dividends.
This period also saw the rise of anabolic steroids in bodybuilding and many other sports. In bodybuilding lore, this is partly attributed to the rise of "mass monsters", beginning with Arnold Schwarzenegger, Sergio Oliva, and Lou Ferrigno in the late 1960s and early 1970s, and continuing through the 1980s with Lee Haney, the 1990s with Dorian Yates, Ronnie Coleman, and Markus Rühl, and up to the present day. Bodybuilders such as Greg Kovacs attained mass and size never seen previously but were not successful at the pro level. Others were renowned for their spectacular development of a particular body part, like Tom Platz or Paul Demayo for the leg muscles. At the time of shooting Pumping Iron, Schwarzenegger (while never admitting to steroid use until long after his retirement) said that "you have to do anything you can to get the advantage in competition". He would later say that he does not regret using anything.
An isolation exercise is one where the movement is restricted to one joint only. For example, the leg extension is an isolation exercise for the quadriceps. Specialized types of equipment are used to ensure that other muscle groups are only minimally involved—they just help the individual maintain a stable posture—and movement occurs only around the knee joint. Most isolation exercises involve machines rather than dumbbells and barbells (free weights), though free weights can be used when combined with special positions and joint bracing.
There are countless reasons to lift weights and build strong muscles, including injury prevention, improved bone density, and a lower risk for type 2 diabetes and other diseases—not to forget that bad-ass feeling you get when you can haul a giant piece of furniture up the stairs all by yourself. Another often-cited benefit to strength training is that it will increase your metabolism. But how much does your metabolism increase with strength training? The answer depends on many different factors.
Creatine is a hydrophilic polar molecule that consists of a negatively charged carboxyl group and a positively charged functional group . The hydrophilic nature of creatine limits its bioavailability . In an attempt to increase creatines bioavailability creatine has been esterified to reduce the hydrophilicity; this product is known as creatine ethyl ester. Manufacturers of creatine ethyl ester promote their product as being able to by-pass the creatine transporter due to improved sarcolemmal permeability toward creatine . Spillane et al  analyzed the effects of a 5 days loading protocol (0.30 g/kg lean mass) followed by a 42 days maintenance phase (0.075 g/kg lean mass) of CM or ethyl ester both combined with a resistance training program in 30 novice males with no previous resistance training experience. The results of this study  showed that ethyl ester was not as effective as CM to enhance serum and muscle creatine stores. Furthermore creatine ethyl ester offered no additional benefit for improving body composition, muscle mass, strength, and power. This research did not support the claims of the creatine ethyl ester manufacturers.
Consult your physician and follow all safety instructions before beginning any exercise program or using any supplement or meal replacement product, especially if you have any unique medical conditions or needs. The contents on our website are for informational purposes only, and are not intended to diagnose any medical condition, replace the advice of a healthcare professional, or provide any medical advice, diagnosis, or treatment.
Co-ingesting creatine with caffeine partially negated the benefits of creatine supplementation (at 5mg/kg bodyweight) during the loading phase in one study. The exact mechanism responsible for this effect is not known, but might be related to opposing actions on muscle contraction time. However, another study in trained men found that co-ingestion of 300mg caffeine per day during creatine loading at 20g per day (split into 4 doses) had no effect on bench press 1RM, time to fatigue, or sprinting ability. However, this study also found that creatine alone or when combined with caffeine had no effect on any of these parameters over placebo, either. Thus, the study may have been underpowered or done in too short a time frame (the test was done after only 5 days of loading) to observe any possible effects.
That means it's an important part of your overall fitness and it benefits people of all ages, plus it may be particularly important for people with health issues such as obesity, arthritis, or a heart condition. The Centers for Disease Control Prevention physical activity guidelines recommend that adults do muscle-strengthening activities on at least two or more days each week (targeting the legs, hips, back, abdomen, chest, shoulders, and arms). (2)
I always recommend starting on the low end of the scale. Only increase volume when you absolutely need to. So, if you’re training chest, you could do 6 work sets of dumbbell bench presses to start out, breaking down to two sets per workout for three sessions per week. You can gradually add sets from there, experimenting with different training splits that will allow you to get in more volume without overtraining (we’ll discuss training splits next).
In young rats given creatine in the diet at 2% of the diet for eight weeks, supplementation appears to increase bone mineral density (BMD) in the lumbar spine with a nonsignificant trend to increase BMD in the femur. Despite the trend, the femur appeared to be 12.3% more resistant to snapping from mechanical stress associated with increased thickness. Menopausal rats (ovarectomized) experience similar benefits, as supplementation of creatine (300mg/kg) for eight weeks during ovarectomy is able to increase phosphorus content of the bone and other biomarkers of bone health, although bone stress resistance was not tested.
Bodybuilding supplements are dietary supplements commonly used by those involved in bodybuilding, weightlifting, mixed martial arts, and athletics for the purpose of facilitating an increase in lean body mass. The intent is to increase muscle, increase body weight, improve athletic performance, and for some sports, to simultaneously decrease percent body fat so as to create better muscle definition. Among the most widely used are high protein drinks, branched-chain amino acids (BCAA), glutamine, arginine, essential fatty acids, creatine, HMB, and weight loss products. Supplements are sold either as single ingredient preparations or in the form of "stacks" – proprietary blends of various supplements marketed as offering synergistic advantages. While many bodybuilding supplements are also consumed by the general public the frequency of use will differ when used specifically by bodybuilders. One meta-analysis concluded that for athletes participating in resistance exercise training and consuming protein supplements for an average of 13 weeks, total protein intake up to 1.6 g/kg of body weight per day would result in an increase in strength and fat-free mass, i.e. muscle, but that higher intakes would not further contribute. The muscle mass increase was statistically significant but modest - averaging 0.3 kg for all trials and 1.0–2.0 kg, for protein intake ≥1.6 g/kg/day.
Bodybuilders also train small muscles with a similar volume, frequency and intensity of their larger muscles. Strength athletes laugh at this. “Curls are a waste of time” is a common phrase you will hear hurled at a bodybuilder. This is SILLY. Although big compound movements should be most people’s resistance training priority, smaller muscle group focus work has some benefits for every athlete. Bicep tears are quite common among strength athletes, especially strong men and powerlifters. This happens because these competitors will lift tremendous weights with their backs, but their biceps are the weak link. Many of these injuries could be prevented with some good old-fashioned bodybuilder type isolation work. If you are only as strong as your weak link, doesn’t it make sense to make those weak links strong ones?
Myotonic Dystrophy type I (DM1) is an inhereted muscular disorder caused by an expanded CTG repeat in the DMPK gene on chromosome 19q13.3 (genetic cause of the disorder) resulting in muscular degeneration and myotonia. The related myopathy, Myotonic Dystrophy type II (DM2) which is also known as proximal myotonic myopathy (PROMM) is due to a CCTG repeat on 3q, and is less affected by myotonia and more by muscular pain and weakness. There is no cure for either because they are genetic disorders, so current therapies are aimed at reducing side-effects. Therapies include modafinil for the somnolence and perhaps creatine for the reduction in strength and functionality.
Post workout, it’s important to restore your body’s energy by consuming protein and carbs. When you’re trying to build muscle, this is an especially important step. Protein powder is a great muscle builder for your post-workout routine, as long as you include a carbohydrate as well. You can get this by eating a banana or adding oats or banana to your protein shake. Or simply cook up a batch of healthy oatmeal muffins and include protein powder in your recipe. Then, enjoy your post-workout supplement as a delicious snack!
Focus on form. Good form means you can reap all of the benefits of your workout and avoid injuries at the same time. To maintain proper form, pay attention to your posture (stand tall with chest lifted and abs held tight), move slowly (this ensures you're relying on muscles, not momentum, to do the lifting), and remember to breathe. Many people hold their breath while exerting, but exhaling during the hardest part of the exercise helps fuel the movement.
I HATE that the resistance training community can be so tribal. I have been preaching to bodybuilders for years about the benefits of powerlifting, or Olympic lifting or kettlebells or even Crossfit style conditioning and many have been receptive. Learn from each other and achieve levels of fitness you simply could not have otherwise. Don’t brush off bodybuilding wisdom…it could be the missing factor in your program.
Creatine (/ˈkriːətiːn/ or /ˈkriːətɪn/ is an organic compound with the nominal formula (H2N)(HN)CN(CH3)CH2CO2H. This species exists in various modifications (tautomers) in solution. Creatine is found in vertebrates where it facilitates recycling of adenosine triphosphate (ATP), the energy currency of the cell, primarily in muscle and brain tissue. Recycling is achieved by converting adenosine diphosphate (ADP) back to ATP via donation of phosphate groups. Creatine also acts as a buffer.
When you’re doing higher reps, focus on the muscle you are trying to build and squeeze every ounce of effort out of it. Yes, cheesie as it may sound, visualizing the muscles working and growing while you train them can be helpful. A 2016 study in the European Journal of Applied Physiology found that, when lifters thought about their pecs and triceps during a workout, they activated them better.
In weight training, as with most forms of exercise, there is a tendency for the breathing pattern to deepen. This helps to meet increased oxygen requirements. Holding the breath or breathing shallowly is avoided because it may lead to a lack of oxygen, passing out, or an excessive build up of blood pressure. Generally, the recommended breathing technique is to inhale when lowering the weight (the eccentric portion) and exhale when lifting the weight (the concentric portion). However, the reverse, inhaling when lifting and exhaling when lowering, may also be recommended. Some researchers state that there is little difference between the two techniques in terms of their influence on heart rate and blood pressure. It may also be recommended that a weight lifter simply breathes in a manner which feels appropriate.
The creatine kinase system appears to be detectable in endothelial cells. Under basal conditions, creatine itself is expressed at around 2.85+/-0.62μM (three-fold higher than HUVEC cells). When incubating the medium with 0.5mM creatine, endothelial cells can take up creatine via the creatine transporter (SLC6A8) and increase both creatine (almost doubling) and phosphocreatine (nearly 2.5-fold) concentrations.
The specific mechanism of intestinal uptake for creatine is not clear, although transporters have been identified in rat jujenum, and confirmed at the mRNA level in humans. The observation that creatine can be absorbed against a concentration gradient to a max ratio of 8:1 (8 times more creatine in the intestinal cell post absorption, relative to the lumen) supports transporter-mediated uptake, and the dependence on sodium and chloride implicate SLC6A8 (Creatine Transporter 1) as the operative transporter.
The creatine transporter is a sodium and chloride dependent membrane-associated transporter that belongs to the Na+/Cl-dependent family of neurotransmitter transporters. In muscle cells and most other cell types, the isomer of the creatine transporter is known as SLC6A8 (solute carrier family 6, member 8). SLC6A8 is encoded by the gene present on the Xq28 region of the human X-chromosome and is expressed in most tissues. A related gene encoding a creatine transporter variant has also been identified at 16p11.1 that is expressed exclusively in the testes. These two transporters share 98% homology.
The majority of creatine in the human body is in two forms, either the phosphorylated form making up 60% of the stores or in the free form which makes up 40% of the stores. The average 70 kg young male has a creatine pool of around 120-140 g which varies between individuals [10,11] depending on the skeletal muscle fiber type  and quantity of muscle mass . The endogenous production and dietary intake matches the rate of creatinine production from the degradation of phosphocreatine and creatine at 2.6% and 1.1%/d respectively. In general, oral creatine supplementation leads to an increase of creatine levels within the body. Creatine can be cleared from the blood by saturation into various organs and cells or by renal filtration .
It’s not just about lifting—it’s about lifting safely and correctly. And if you’re not performing exercises properly, it’s impossible to make any progress. “When someone is just starting to work out, it can help to work closely with a knowledgeable personal trainer in order to learn proper form,” says Ingram. But that goes for experienced lifters, too. If you aren’t sure about a movement, it’s better to ask. “If you’re not working the correct muscles, you can’t expect them to grow,” explains Ingram.
Children: Creatine is POSSIBLY SAFE in children when taken by mouth appropriately. Creatine 3-5 grams daily for 2-6 months has been taken safely in children 5-18 years of age. Creatine 2 grams daily for 6 months has been taken safely in children 2-5 years of age. Additionally, creatine 0.1-0.4 grams/kg daily for up to 6 months has been taken safely in both infants and children.
Contrary to the sound of the name, glucosamine is not a glucose replacement drink but a naturally occurring compound that has received publicity and wide support as a supplement for the relief of arthritis pain and possible prevention of further joint damage. Glucosamine has been popular with sports people of all types, including weight trainers, particularly for knee arthritis and pain. Glucosamine seems to be safe to use.
Squats target both your inner and outer thighs. Use a barbell heavy enough to challenge your muscles but light enough that you can still control your form. Hold it behind your head with your feet shoulder-width apart. Tighten your core, then squat down as far as comfortable. There should be no knee or back pain. As you come back up, raise your hips and chest together.
Terry follows the old-school bodybuilding mentality of isolating each muscle group (back, shoulders, chest, legs and arms) on a five-day cycle. If he’s trying to grow a certain muscle group, he’ll introduce a second workout on the sixth day. Each of Terry’s workouts lasts between 60 and 90 minutes – “any longer and you're either not pushing yourself hard enough or you're talking too much” – and he makes the most of each session by targeting different parts of each muscle.
Incubation of a β-cell with additional creatine (5-10mM), even at saturated concentrations of glucose, is able to further increase insulin secretion in response to glucose, specifically as the leucine metabolite 2-ketoisocaproic acid, potassium, and a potassium channel blocker were all ineffective. This has been found to occur in rats given 2% of the diet as creatine but has since failed in humans given 5g of creatine.
Every gym has a guy shaped like a lightbulb. He's the one who neglects his lower body. If you don't want to be that guy, work your major leg muscles on the leg press machine. Place your feet on the plate with knees bent at 90 degrees. Grasp the handles and slowly push the plate out until your knees are straight but not locked. Pause and slowly return to the starting spot.
Besides the high-quality protein content of casein/whey, the newer formulations have little or no lactose (i.e., milk sugar), which some people have negative reactions to. The native milk proteins also provide a host of smaller proteins called peptides, many of which, such as lactoferrin, have vital health benefits. The rich cysteine content of whey acts as a precursor of glutathione, a primary endogenous antioxidant and liver detoxifier in the body.
When you’re planning your high-protein meals, 20 grams of protein is the optimal amount generally accepted for muscle growth. Research has found that the body doesn’t use much more than 20 grams for muscle-building at any one sitting. Around 80 grams of protein per day (or, four meals containing 20-grams of protein each) is about right for most people.
Research shows that strength training is especially effective at raising EPOC. That’s because, generally speaking, strength-training sessions cause more physiological stress to the body compared to cardiovascular exercise, even higher-intensity cardio intervals. However, it’s worth noting that overall exercise intensity is what makes the biggest impact on EPOC. So squats, deadlifts, and bench presses with heavy weights are going to be much more effective at raising EPOC compared to bicep curls and triceps extensions with light weights.
Creatine citrate is creatine bound to citric acid, or citrate. Creatine citrate does not differ greatly from monohydrate in regard to absorption or kinetics. Note that creatine citrate is more water-soluble than monohydrate, but creatine absorption is generally not limited by solubility. The increased water solubility may play a factor in palatability.
Perform the exercise pairs (marked A and B) as alternating sets, resting 60 seconds between sets. You’ll complete one set of exercise A and rest; then one set of B and rest again; and repeat until you’ve completed all sets for that pair. On your very first training day, perform only one set for each exercise. Progress to two or more sets (as the set prescriptions below dictate) from your second workout on.
Weight training also requires the use of 'good form', performing the movements with the appropriate muscle group, and not transferring the weight to different body parts in order to move greater weight (called 'cheating'). Failure to use good form during a training set can result in injury or a failure to meet training goals; since the desired muscle group is not challenged sufficiently, the threshold of overload is never reached and the muscle does not gain in strength. At a particularly advanced level; however, "cheating" can be used to break through strength plateaus and encourage neurological and muscular adaptation.
One limitation of many free weight exercises and exercise machines is that the muscle is working maximally against gravity during only a small portion of the lift. Some exercise-specific machines feature an oval cam (first introduced by Nautilus) which varies the resistance, so that the resistance, and the muscle force required, remains constant throughout the full range of motion of the exercise.
Start with the barbell on the supports of a power rack at about shoulder height. Grab the bar overhand and raise your elbows until your upper arms are parallel to the floor. Now lift the bar off the rack, letting it roll toward your fingers-this is where it should rest throughout the exercise (as long as you keep your elbows raised, you won’t have trouble balancing the bar) . Squat as low as you can , and then drive with your legs to return to the starting position. That’s one rep.
Wilkinson, S. B., Tarnopolsky, M. A., MacDonald, M. J., MacDonald, J. R., Armstrong, D., & Phillips, S. M. (2007). Consumption of fluid skim milk promotes greater muscle protein accretion after resistance exercise than does consumption of an isonitrogenous and isoenergetic soy-protein beverage. The American Journal of Clinical Nutrition, 85(4), 1031-1040.
Crave instant gratification? Strength training is a good motivator because you see progress quickly. “If you put someone on a walking program, it will take time before they perceive their body is changing,” explains Katula. “But with strength training, you can feel a difference in your muscles even after one session.” And it only takes a couple workouts before you’ll notice some muscle definition in the mirror. (Go ahead and flex. We dare you.)
Some people do have allergies to soy, or they have an intolerance to soy. If you notice certain symptoms (like a headache) after soy consumption, you may have an intolerance. Discovering your food intolerances/allergies would also be handled by a Dietitian. For the general population who are not allergic/intolerant to soy, however, soy-based products can be a part of a healthy diet. New research has shown that soy is not harmful as people fear. If soy gives you issues, you could always opt for whey protein, pea protein or other forms of vegetable protein. Have you seen our article on protein powders? Click here.
A muscle imbalance—when one muscle is stronger than its opposing muscle—can limit your ability to exercise effectively, and could lead to injury down the line. “It’s important to recognize whether you’re really working the muscles you think you are and recognize if you’ve developed an imbalance that alters your movement pattern,” says Eric Ingram, physical therapist at Louisiana Physical Therapy Centers of Pineville. One common imbalance in women is stronger quads and weaker, tighter hamstrings, thanks to prolonged sitting, high heels, and improper training. If you suspect you have a muscle imbalance, make an appointment with a physical therapist, who will prescribe exercises to even you out.
In regard to practical interventions, concurrent glycogen loading has been noted to increase creatine stores by 37-46% regardless of whether the tissue was exercised prior to loading phase. It is important to note, however, that creatine levels in response to the creatine loading protocol were compared in one glycogen-depleted leg to the contralateral control leg, which was not exercised. This does not rule out a possible systemic exercise-driven increase in creatine uptake, and the increase in creatine noted above was larger than typically seen with a loading protocol (usually in the 20-25% range). Consistent with an exercise-effect, others have reported that exercise itself increases creatine uptake into muscle, reporting 68% greater creatine uptake in an exercised limb, relative to 14% without exercise.
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.
Syrotuik and Bell  investigated the physical characteristics of responder and non-responder subjects to creatine supplementation in recreationally resistance trained men with no history of CM usage. The supplement group was asked to ingest a loading dosage of 0.3 g/kg/d for 5 days. The physiological characteristics of responders were classified using Greenhaff et al  criterion of >20 mmol/kg dry weight increase in total intramuscular creatine and phosphocreatine and non responders as <10 mmol/kg dry weight increase, a third group labeled quasi responders were also used to classify participants who fell in between the previously mentioned groups (10-20 mmol/kg dry weight). Overall, the supplemented group showed a mean increase in total resting muscle creatine and phosphocreatine of 14.5% (from 111.12 ± 8.87 mmol/kg dry weight to 127.30 ± 9.69 mmol/kg dry weight) whilst the placebo group remained relatively unaffected (from 115.70 ± 14.99 mmol/kg dry weight to 111.74 ± 12.95 mmol/kg dry weight). However when looking at individual cases from the creatine group the results showed a variance in response. From the 11 males in the supplemented group, 3 participants were responders (mean increase of 29.5 mmol/kg dry weight or 27%), 5 quasi responders (mean increase of 14.9 mmol/kg dry weight or 13.6%) and 3 non-responders (mean increase of 5.1 mmol/kg dry weight or 4.8%). Using muscle biopsies of the vastus lateralis, a descending trend for groups and mean percentage fiber type was observed. Responders showed the greatest percentage of type II fibers followed by quasi responders and non-responders. The responder and quasi responder groups had an initial larger cross sectional area for type I, type IIa and type IIx fibers. The responder group also had the greatest mean increase in the cross sectional area of all the muscle fiber types measured (type I, type IIa and type IIx increased 320, 971 and 840 μm2 respectively) and non-responders the least (type I, type IIa and type IIx increased 60, 46 and 78 μm2 respectively). There was evidence of a descending trend for responders to have the highest percentage of type II fibers; furthermore, responders and quasi responders possessed the largest initial cross sectional area of type I, IIa and IIx fibers. Responders were seen to have the lowest initial levels of creatine and phosphocreatine. This has also been observed in a previous study  which found that subjects whose creatine levels were around 150 mmol/Kg dry mass did not have any increments in their creatine saturation due to creatine supplementation, neither did they experience any increases of creatine uptake, phosphocreatine resynthesis and performance. This would indicate a limit maximum size of the creatine pool.
If your fitness goals are to get strong and build hard, visible muscle, then you’re going to want to train in three phases according to Heath. Strength, conditioning, and a blend of the two that works for you. “If you can get to the gym 4-5 days a week, that would be perfect,” he says. “You can still do chest/tri’s, back/bi’s, legs, shoulders, and make the fifth day a cleanup day, meaning focus on body parts you may be weaker in.” Check out Heath’s guide to finding your best muscle-building routine.
In humans, studies that investigate links between serotonin and creatine supplementation find that 21 trained males, given creatine via 22.8g creatine monohydrate (20g creatine equivalent) with 35g glucose, relative to a placebo of 160g glucose, was found to reduce the perception of fatigue in hot endurance training, possibly secondary to serotonergic modulation, specifically attentuating the increase of serotonin seen with exercise (normally seen to hinder exercise capacity in the heat) while possibly increasing dopaminergic activity (conversely seen to benefit activity in the heat).