In well-trained endurance runners, creatine (with glycerol for hyperhydration) caused a relatively large increase in body weight gain (0.90+/-0.40kg) and water weight (0.71+/-0.42L) but failed to negatively influence performance over 30 minutes in the heat. This failure to improve physical performance in the heat with creatine loading (despite water retention) has been noted elsewhere.
A 2011 survey of 33 supplements commercially available in Italy found that over 50% of them exceeded the European Food Safety Authority recommendations in at least one contaminant. The most prevalent of these contaminants was creatinine, a breakdown product of creatine also produced by the body. Creatinine was present in higher concentrations than the European Food Safety Authority recommendations in 44% of the samples. About 15% of the samples had detectable levels of dihydro-1,3,5-triazine or a high dicyandiamide concentration. Heavy metals contamination was not found to be a concern, with only minor levels of mercury being detectable. Two studies reviewed in 2007 found no impurities.
In addition to the BBB, SLC6A8 is also expressed on neurons and oligodendrocytes, but is relatively absent from astrocytes, including the astrocytic feet which line 98% of the BBB. Creatine can still be transported into astrocytes (as well as cerebellar granule cells) via SLC6A8, as incubation with an SLC6A8 inhibitor prevents accumulation in vitro. It seems to be less active in a whole brain model, relative to other brain cells.
Healthy sources of fat include: cold water oily fish (such as salmon, mackerel, and sardines), extra-virgin olive oil, peanuts (unsalted), avocado, pecans, almonds, hazelnuts, walnuts or flaxseed. Nuts (any sort, just make sure they are unsalted) are a great food to snack on if you're having trouble gaining weight, as they are not only high in calories, but they contain monounsaturated fats, a good source of protein, fibre and contain a number of essential minerals that are needed for health. For those not consuming any oily fish, you may want to consider taking a fish oil supplement, such as cod liver oil or flaxseeds.
It is possible that females could benefit more than males due to a combined lower creatine kinase activity as well as having altered purine metabolism during depression, but no human comparative studies have been conducted yet. One rat study noted that creatine monohydrate at 2-4% of feed had 4% creatine able to exert anti-depressive and anxiolytic effects in female rats only.
If you're a beginner, just about any workout will be intense enough to increase protein synthesis. But if you've been lifting for a while, you'll build the most muscle quickest if you focus on the large muscle groups, like the chest, back, and legs. Add compound lifts like squats, deadlifts, pullups, bent-over rows, bench presses, dips, and military presses to your workout to work them the most efficiently.
The main consequence to using weight training exercises is the increase in muscle strength that you'll develop over time. You'll also develop stronger bones as well as gain a better general posture. In short, maintaining good muscle strength will allow your body to move more freely from the moment you wake up in the morning to the moment you fall asleep at night.
Why less volume for the smaller muscle groups, you ask? Partially because they are smaller, but mostly because they get a ton of indirect volume while training the bigger muscle groups (e.g. your biceps get hit pretty hard while training back, triceps get hit pretty hard while training chest and shoulders, shoulders get hit pretty hard while training chest, etc.).
Collectively the above investigations indicate that creatine supplementation can be an effective strategy to maintain total creatine pool during a rehabilitation period after injury as well as to attenuate muscle damage induced by a prolonged endurance training session. In addition, it seems that creatine can act as an effective antioxidant agent after more intense resistance training sessions.