Supplements are an inflammatory topic. You have naturalists on one side touting the benefits of eating only real food, vilifying the supplement industry by pointing out its (legitimate) flaws.
On the other side, you have proponents touting anecdotal and scientific evidence supporting performance-boosting benefits of specific nutrients and compounds. So who's right?
As is so often the frustrating case, each side has some merit. If you're looking for performance boosters that actually, you know, work, Krissy Kendall, PhD, CSCS*D, CISSN, EP-C (in other words, a highly certified nutrition and exercise science expert), and the science editor for Bodybuilding.com, points out the four supplements that are actually worth taking. Since the supplement industry isn't tightly regulated, you should always research and look for reviews from independent testing organizations before spending money on any supplement. After that, all that's left is actually working out.
Supplemental creatine has been around for decades. I vividly remember my scrawny older brother mixing up post-workout drinks filled with the stuff in the early '90s. He ended up playing Division 1 football. Coincidence? Who's to say, really? (I'm sure genetics and a lot of hard work fit in there somewhere.)
At any rate, the supplement is legit. Kendall points out that it helps on multiple fronts as an aid for enhancing power, building muscle, and boosting endurance. She says, "Creatine supplementation works by increasing the availability of creatine and phosphocreatine (PCr) within the muscle, helping to maintain energy during high-intensity exercise such as weightlifting, circuit workouts, and tempo runs. Increasing the availability of PCr may also help speed up recovery between sets."
Because of the length of time creatine has been on the market, there are literally hundreds of research studies published supporting its benefits and safety. Back in the day, there was some concern that supplementing with creatine screwed up your kidneys, but subsequent research has shown that's not a concern for the vast majority of healthy people.
Kendall also notes that while creatine gets most of its cred for improving muscular strength and size, it's also a powerhouse for endurance athletes, particularly during interval workouts at lactate threshold, speed work, and hill routines. "Creatine supplementation has been shown to decrease recovery time during repeated intervals, and increase power output at lactate threshold. Improvements in speed, power, and running economy during your training sessions translates to better race-day performance."
To get the best results, Kendall says the recommended dose is 3 to 5g per day. "Skip over the traditional loading phase often used with creatine supplementation. The initial weight gain, which is caused by an increase in total body water, may slow down performance."
A surefire way to get the most out of your training sessions is to figure out a way to delay fatigue, essentially allowing you work harder, longer. In the right environment, that's exactly what beta-alanine can do for you. There's science to it, of course, as Kendall explains, "During highly intense training sessions, your body accumulates hydrogen ions. These ions contribute to a drop in the pH inside your muscle, ultimately leading to fatigue. Delaying fatigue is, in part, related to the concentration of carnosine (an amino acid) found within the muscle."
Enter beta-alanine, a precursor to carnosine. When you supplement with beta-alanine, you're essentially giving your body the compounds it needs to increase levels of carnosine, ultimately helping delay fatigue. That said, there haven't been as many studies supporting its long-term safety, so while it appears to improve exertion and fatigue, use caution if you plan on taking it for an extended period of time.
You can take beta-alanine at any point throughout the day, but Kendall recommends taking a total of 3 to 6g a day, separated into multiple doses of 800mg. This method "reduces the effects of paresthesia, a temporary tingling or numbness akin to when a limb falls asleep."
Caffeine has been around for centuries as a performance enhancer, so whatever your feelings about coffee are, you can rest assured that it's safe. Kendall points to the many, many years' worth of research backing the positive performance benefits of caffeine on endurance and high-intensity activity. Specifically, "Caffeine has been shown to decrease rates of fatigue and lower perception of effort, which may be of benefit during high-intensity, high-volume workouts, or if you just need a little pick-me-up before hitting the weights."
Kendall just has one word of caution, "Don't make the mistake of taking your caffeine supplement or pre-workout drink as you walk into the gym. To take full advantage of the powers of caffeine, try to have it about 30 to 45 minutes before your workout." She also notes that caffeine will affect you differently if you're not a regular user, "Caffeine newbies will likely see a benefit using a dose around 150 to 200mg. If you're a chronic caffeine user, you may need to go up closer to the 300mg mark."
Branched-chain amino acids
Branched-chain amino acids, or BCAAs, include the amino acids leucine, isoleucine, and valine. They've gotten a lot of press in recent years, and for good reason. Kendall states, "It's well-known that BCAAs, especially leucine, help to regulate protein metabolism by promoting protein synthesis and suppressing protein breakdown. This can help to speed up the recovery process of muscles damaged during resistance training."
In other words, a BCAA supplement could help you recover more quickly while reducing the experience of delayed onset muscle soreness, helping you feel a little bit better the next time you hit the gym. Even better, you might find your BCAA supplement helps you increase workout intensity and endurance capacity. It all gets pretty technical, but Kendall explains, "Since BCAAs and tryptophan (another amino acid) compete for the same protein carrier, increasing BCAA concentrations can reduce the amount of tryptophan crossing the blood-brain barrier (BBB), reducing the amount of serotonin produced, potentially delaying fatigue."
Your best bet for enhanced performance is to consume about 6 to 10g before or during exercise. Kendall advises that a ratio of 2:1:1 of leucine, isoleucine, valine appears to be most beneficial.