Which of the following potential strategies produces significant gains in performance or body composition in the least amount of time?
A. Better Training Program
B. Changes in Diet
C. Use of Supplements
D. They All Work Equally Quickly
The answer is C, the use of supplements. Changing your training program produces performance changes in weeks and body composition improvements in months. Changes in diet may affect your performance and physique a little faster, but generally it’s a fairly long, drawn out process.
Taking a supplement like caffeine pre-competition will improve your performance instantly. Or consuming high-antioxidant fruit extracts such as blueberry or tart cherry juice will immediately accelerate your recovery after you thrash your muscles in the gym. There’s no loading period required.
These are supplements that you can “use as you please” and they’ll give you an immediate lift. Then there are supplements that require a bit more diligence and time if you want to experience benefits.
For instance, carnitine is one of the most powerful performance-enhancing nutrients and it conveys different benefits if you just take it pre-workout compared to if you supplement with it for a sustained time period. This is one reason that carnitine performed poorly in the first research studies that tested it.
Glutamine suffers from a similar dilemma—research doesn’t support its use in healthy trainees because the dose measured in trials thusfar is too small. Hopefully, scientists testing the benefits of glutamine will be as innovative in their thinking as those who have recently produced a series of studies showing that carnitine can enhance performance and aid in fat loss.
This article will tell you what you need to know to benefit from carnitine. It will highlight how it can help you overcome the factors that limit athletic performance and the loss of body fat.
#1: Carnitine improves exercise performance and reduces RPE
Two years ago, a breakthrough study found that giving 2 grams of carnitine with 80 grams of carbs twice a day to experienced triathletes for 6 months allowed them to compete longer at a higher intensity and it felt easier. The athletes improved their performance by 11 percent from baseline and rated a 30-minute workout at 80 percent of maximal as easier on a rating of perceived exertion scale.
Scientists found that the participants had a 55 percent reduction in the use of muscle glycogen during exercise. Lower use of glycogen means they were relying more on fat to keep them going.
Sparing glycogen is a superior technique for improving endurance performance because it means you can use both the fat and glycogen in your body to fuel exercise, allowing you to train harder for longer. When glycogen runs out, it is a performance-limiting factor.
Now, the same research group tested whether taking carnitine with 80 grams of carbs twice a day would keep young athletes from gaining fat compared to if they just took the carbs without carnitine. It did.
#2: Carnitine reduces fat gain when supplementing with carbohydrates
In this study, participants took either 1.4 grams of carnitine with 80 grams of carbs twice a day or took just the carbs for 12 weeks. The reason that carnitine is paired with carbs is that insulin is required to “load” the carnitine into the muscle.
There’s some evidence that nutrients that require the presence of insulin to load can be effective when taken with “insulin-like” substances. For example, studies have shown that the herb fenugreek and the plant extract D-pinitol will load creatine as effectively as carbs. Alpha lipoic acid has also been found to load creatine.
Just keep in mind that it’s possible that you can get benefits from carnitine without carbs. Now, when you do consume extra carbs, it’s probable that you’ll gain body fat as was seen in this study: The carb-only group gained 1.7 kg of body fat, whereas the carnitine-carb group gained no fat.
The reason that carnitine kept the men from putting on weight with the added calories is twofold:
First, taking carnitine allowed for the men to increase the use of fat for energy, which was revealed during a low-intensity exercise test at the end of the study. Carnitine is responsible for the transport of fats into the cells to be used for energy in the body, making it a potent fat burner.
Second, taking carnitine led to an increased energy expenditure, which is the primary reason that the group gained no fat—they were burning more calories. During the exercise test, they burned 6 percent more energy, which scientists think is just enough of an increase to counteract the excess energy intake from the carbs.
The researchers concluded that by raising the level of muscle carnitine, you support the fat burning process, and because your body becomes more efficient at processing fuel, it will increase your energy levels.
#3: Carnitine increases running speed and reduces lactate production
A third new carnitine study shows what happens when you take it right before training instead of chronically, as occurred in the others. This study used professional Turkish soccer players and compared a placebo with either a 3 or 4-gram dose of carnitine taken with fruit juice to supply the carbs on high-intensity running performance.
Results showed that the carnitine groups were able to achieve faster running speeds corresponding to specific lactate concentrations. Heart rate was also lower at specific running speeds following the carnitine supplementation. There was no difference in performance between the 3- and 4-gram doses, indicating that 3 grams may be the threshold dose needed to enhance performance acutely.
Simply, carnitine was found to delay the time it took to reach the anaerobic threshold by using the athletes’ aerobic energy system more effectively. This allowed for fatigue to occur later and performance to be enhanced.
In addition, rating of perceived exertion was lower in the carnitine trials than placebo. This makes sense because when lactate buildup is reduced and the body functions more efficiently, intense exercise will “feel” easier.
Scientists think carnitine is beneficial because it has a protective effect on the blood cells and can prevent muscle damage during exercise. It’s known to prevent cell damage and aid in wound healing, while boosting immunity of cells.
The bottom line is that carnitine is a potent defense that helps you overcome a variety of limiting factors:
- reduced “waste” buildup (lower lactate)
- reduced muscle damage
- greater fat oxidation
- sparing of glycogen
In addition, carnitine will speed recovery from extreme exercise because it upregulates the signaling of genes and androgen receptors. Check it out.
#4: Carnitine improves androgen sensitivity and can raise low testosterone.
Two studies led by William J. Kraemer found that supplementing with carnitine for three weeks led to increased protein synthesis after resistance training. Protein synthesis is how the body builds muscle and heals injured tissue, whether from resistance training or an injury.
In addition, the androgen receptors that bind with testosterone were enhanced, which scientists believe will “help to mediate quicker recovery.” The benefit of getting abundant carnitine may go further to raise testosterone in people who have poor health and low androgen hormones.
A Japanese study found that carnitine levels were associated with free testosterone concentration in male patients with kidney disease. Another study found that older men aged 60 to 74 who took 2 grams of propionyl-L-carnitine and 2 grams of acetyl-L-carnitine improved reproduction function and mood. Rather amazingly, just taking carnitine was as effective as taking supplemental testosterone in this study.
Based on studies in rats, it’s thought that carnitine may actually help the body to produce more testosterone. Whether carnitine will raise testosterone in healthy people is unknown, but the fact that it increases the action of the androgen receptors is highly favorable for better tissue repair and muscle development.
#5: How, when, and where to get carnitine
Carnitine is stored in muscle with total carnitine content in the human body being 300 mg per kg. That means a 70 kg individual could store about 21 grams in muscle. The body can produce a small amount (about 25 percent of requirements) and the rest has to be gotten from diet.
Meat and animal products are the only source of carnitine, with beef providing about 90 mg per 4 ounces. From a therapeutic perspective, vegetarians and people who are ill are at risk of deficiency of carnitine and may benefit from supplementation. Clearly, from the evidence presented above, meat eaters can experience performance benefits (none of the study subjects were documented vegetarians).
To get athletic performance results, a few things are important:
First, it takes a long supplementation period to raise muscle carnitine levels. In the study of triathletes, there were no changes in performance after 3 months from baseline, but after 6 months those improvements were pronounced and statistically significant.
Second, carnitine doesn’t “load” in muscle unless accompanied by high insulin concentrations. This explains why many previous studies have not shown increases in muscle carnitine after taking it in multi-gram doses. Taking carnitine with carbohydrates is one way to ensure “loading” but you can also consume carnitine with a protein source that raises insulin, such as whey protein.
If your goal is fat loss or weight management, you may want to be cautious about supplemental carbs. In this case, you can take carnitine with a protein supplement, or there are other insulin-like nutrients that help load carnitine, including fenugreek or alpha lipoic acid. Alternatively, you can take your carnitine as part of any mixed meal that contains some carbohydrates and protein—it’s not required that you take it as part of pre- or post-workout supplement, though some people find doing so improves their motivation to train.
For improvements in exercise performance, studies show benefits from 2 to 4 grams a day, often taken in divided doses, such as 2 grams at breakfast, and 2 grams post-workout.
Carnitine tartrate is the most common form for improving exercise performance, but there is evidence that a blended form that contains acetyl-l-carnitine can be just as effective while supporting mood, cognition, and cardiovascular function. Adding a third form, propionyl l-carnitine, will improve blood flow, support cardiovascular health, and benefit gut health. We offer all three in our Carnitine Synergy, which also combines the thermogenic green tea extract with the brain support amino acid acetyl-l-tyrosine to help you take your training to the next level.