Creatine supplementation may be able to enhance lifespan, secondary to increasing intracellular carnosine stores. Carnosine is the metabolic compound formed from beta-alanine supplementation, and in a mouse-model for premature aging (senescence-accelerated premature aging, SAMP8) creatine supplementation without any beta-alanine has been shown to increase cellular carnosine stores. That being said, the aforemented SAMP8 study noted an increase in carnosine levels at middle age, but not old age in the mice. A human study using 20g of creatine for one week in otherwise healthy people failed to find an increase in intracellular carnosine stores.
There have also been concerns that creatine can cause kidney damage, and doctors warn that people with a history of kidney disease or conditions, such as diabetes, that increase the risk of kidney problems should steer clear of the supplement. Combining creatine with nephrotoxic drugs — drugs that might damage the kidneys — like nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen (advil or motrin) and naproxen sodium (Aleve), should also be avoided, according to the U.S. Department of Health and Human Services. (1)
Creatine has been incubated in various cell lines (HUVEC, C2C12, U937) and noted to reduce cellular death from various pro-oxidant stressors, such as H2O2 or peroxynitrate in an intracellular range between 0.1-10mM. This protective effect was only noted with preincubation and was comparable to 10-100µM of Trolox. This protective effect did not require conversion into phosphocreatine nor a buffering of ATP, and only worked during a preloading to the stressor, rather than in a rehabilitative manner.
The 1960s saw the gradual introduction of exercise machines into the still-rare strength training gyms of the time. Weight training became increasingly popular in the 1970s, following the release of the bodybuilding movie Pumping Iron, and the subsequent popularity of Arnold Schwarzenegger. Since the late 1990s increasing numbers of women have taken up weight training, influenced by programs like Body for Life; currently nearly one in five U.S. women engage in weight training on a regular basis.
D-aspartic acid can also help to reduce cortisol levels. Cortisol is known as the “stress” hormone because its production increases during stressful situations. High cortisol levels can have many negative side effects, such as weight gain, muscle tissue breakdown, or increased blood sugar. Taking a supplement that includes cortisol can reduce stress and prevent excess fat storage or muscle loss.
As I mentioned earlier, the exercises that come first in your workout (aka primary compound exercises) should usually be done in the 5-8 rep range. Exercises in the middle (aka your secondary compound exercises) should usually be done in the 8-10 rep range. Exercises done at the end of your workout (which is typically where isolation exercises belong) should usually be done in the 10-15 rep range.
Having a strong butt will get you far—literally. Our glutes are responsible for powering us through everything from long runs to tough strength workouts to a simple jaunt up a flight of stairs. Strong glutes that can take on the brunt of the work can help us avoid overcompensating with smaller muscles during lower-body exercises. Plus, beyond just helping us move, the glutes play an important role in "stabilizing our entire lumbo-pelvic-hip complex," says Cori Lefkowith, NASM-certified personal trainer and owner of Redefining Strength in Costa Mesa, California. That translates to better form, more efficient movement, and a reduced risk of straining your lower back and hips.