Our science editor, Krissy Kendall, PhD, CISSN, answers your questions relating to nutrition and supplementation to optimize your health and performance!
Vital Stats
Name: Krissy Kendall, PhD, CISSN
Education: MS and PhD in exercise physiology, University of Oklahoma
Occupation: Bodybuilding.com science editor
Are there any health benefits to drinking apple cider vinegar?
Vinegar has been used for cooking and cleaning for ages, but a growing number of people are using vinegar for health purposes. Some proponents of apple cider vinegar claim it can help you lose weight, and the especially hardcore say it can cure a wide variety of ailments including diabetes, bad breath, acne, and high cholesterol!
Let's examine a few of the more popular claims about vinegar.
Claim 1: It can lower blood glucose levels following a carbohydrate-rich meal.
This is especially true for those with pre-diabetic symptoms, or who have been diagnosed with type 2 diabetes. A 2004 study published in the Journal of Diabetes Care found that taking vinegar before meals significantly increased insulin sensitivity and reduced glucose levels by 25 percent for those with type 2 diabetes, and cut glucose levels by nearly half in those with pre-diabetic symptoms.1
As far as we know now, diabetics may be the only group to benefit from apple cider vinegar. Taken with a high-glycemic meal, vinegar has been shown to significantly reduce the glucose response.2 A second study by the same group of researchers found that post-meal glucose response was affected favorably only when the vinegar was ingested at meal time with carbohydrates. Although the exact mechanisms for this are unclear, it could be due to vinegar's ability to delay gastric emptying.
Claim 2: It may help lower cholesterol levels and blood pressure.
Dietary intake of vinegar has been shown to lower triglyceride levels, reduce low-density lipoproteins (LDL), and raise high-density lipoproteins (HDL). Additionally, there is some support that the acetic acid found in vinegar can lower blood pressure. Here's the catch: The majority of research has only been done in animal studies.
For humans, the picture is a lot less clear. A group of researchers from the University of Minnesota found no improvements in cholesterol levels following two months of vinegar consumption (2 tablespoons a day).3 At this point, we really need more research using human subjects before we can draw any sort of conclusion on the effects of apple cider vinegar on cholesterol and blood pressure.
Claim 3: It can be used as an appetite suppressant.
Studies examining the role of vinegar as an appetite suppressant aren't too promising, either. A study published in the International Journal of Obesity found that ingestion of apple cider vinegar prior to a meal increased satiety, or feelings of fullness.4 However, this was largely due to poor tolerability to the vinegar and subsequent feelings of nausea. I suppose that's one way to control appetite, but not something I would recommend!
Claim 4: It's an "overall health booster!"
As for those individuals who claim vinegar is full of nutrients that can improve your overall health, they're straight-up lying to you. According to the USDA, apple cider vinegar has no measureable vitamin A, B-6, C, E, thiamin, riboflavin, beta-carotene, or folate. Furthermore, there are no traceable amounts of amino acids, lycopene, or any other nutritional element.
Take-Home Message
My recommendation is to save your vinegar for the next time you decide to clean your windows or decorate Easter eggs. If you do feel compelled to try it out, keep in mind that apple cider vinegar is highly acidic, so you should dilute it with water or juice before swallowing. Although the risk is low if you stick to consuming small amounts, straight apple cider vinegar can damage your teeth or the tissue of your mouth and throat.
Although there is a lack of evidence at this time to support the role of apple cider vinegar as a weight-loss tool or treatment for chronic diseases like diabetes and cardiovascular diseases, it is considered safe to consume in reasonable amounts.
I've noticed TeaCrine® popping up in a lot of pre-workouts lately. What is it, and what are the benefits of taking it?
There has been a lot of buzz around a new dietary ingredient known as TeaCrine®. It's a patented form of the naturally occurring compound theacrine, and it's similar to caffeine in chemical makeup and effects.
Think of theacrine as a modified version of caffeine. You can expect similar performance benefits—more energy, focus, and motivation—but without the post-workout energy crash that caffeine can sometimes cause. Theacrine may also have less of an impact on blood pressure and tolerance buildup compared to caffeine.
A published abstract presented at the International Society of Sports Nutrition Annual Conference found that a 200-milligram dose of TeaCrine® caused significant improvements in energy levels and reductions in fatigue.5
However, due to the overall lack of clinical studies at this time, we can't conclusively say whether or not TeaCrine® is as effective as caffeine.
Take-Home Message
If you're searching for a new stimulant to give your performance in the gym a boost, give TeaCrine® a shot. More research needs to be done on the ingredient, but as it stands now, it appears to be both safe and effective.
It's also a great alternative for someone sensitive to caffeine. It'll still increase your energy levels, but it's less likely to disrupt your sleep or be habit-forming.
What's the difference between sodium phosphate and sodium bicarbonate? Will either one help my performance?
The names may sound similar, but these two performance-boosting ingredients shouldn't be confused for one another. To put it simply, sodium phosphate will exhibit most of its benefits during endurance-like activities, whereas sodium bicarbonate shines during high-intensity activities.
Sodium phosphate works by enhancing the ability of red blood cells to deliver oxygen to active muscles. Research conducted at the University of Florida found that sodium-phosphate-loading increased maximal oxygen consumption by 12 percent, lowered lactate levels, and increased work output.6
Most of the research using sodium phosphate has been conducted in endurance athletes, suggesting this supplement might be best for those competing in long-duration events like running and cycling. It's important to note that other forms of phosphate (calcium phosphate, potassium phosphate) do not seem to possess the same ergogenic (performance-enhancing) benefits.
For most people, sodium phosphate is a relatively safe supplement when used occasionally and when taking no more than 4 grams per day. When consumed in excess, sodium phosphate can have a negative impact on kidney function and may cause an irregular heartbeat.
Sodium bicarbonate, also known as baking soda, is a common ingredient you probably already have in your pantry. Bicarbonate does exist naturally in your body, but supplementing with additional sodium bicarbonate may help to eliminate hydrogen ions and reduce the acidity of your blood.
During high-intensity activity, your body accumulates large amounts of hydrogen ions during the process of glycolysis. If these hydrogen ions can't be cleared quickly enough, the pH of your blood becomes more acidic, making it much harder for your muscle to contract. This is what causes the burning sensation you've probably experienced during exhausting workouts.
Supplementing with sodium bicarbonate can act as a buffer, preventing the accumulation of hydrogen ions and ultimately enhancing your performance in exercises that are short in duration. While it may not get you on the Road to Rio, sodium bicarbonate can improve performance by about 1-2 percent in activities lasting 2-7 minutes.7,8
Be warned that this does come at a cost, though. Individuals supplementing with sodium bicarbonate have experienced stomach disruptions like nausea, bloating, and reflux. Diarrhea and flatulence can also occur for up to 24 hours after ingestion, but this should improve with continued use. Taking smaller doses throughout the day (rather than one large one) can also help mitigate these symptoms.
Take-Home Message
To improve your endurance performance, try supplementing with sodium phosphate for 3-6 days before your event. The recommended dose is 1,000 milligrams taken four times daily.
Stick with sodium bicarbonate if you're looking for improvements in your short-term, high-intensity performance. The recommended dose is 90-140 milligrams per pound of body weight. I strongly advise that you start with lower doses to see how your GI system reacts to the supplement.
It's always best to test out these supplements well before any race or competition. The last you need is an upset stomach affecting your performance!
Do you have a question for Dr. Kendall? Place it in the comments section below—it might be chosen for an upcoming installment!
References
- Johnston, C. S., Kim, C. M., & Buller, A. J. (2004). Vinegar improves insulin sensitivity to a high-carbohydrate meal in subjects with insulin resistance or type 2 diabetes. Diabetes Care, 27(1), 281-282.
- Johnston, C. S., & Buller, A. J. (2005). Vinegar and peanut products as complementary foods to reduce postprandial glycemia. Journal of the American Dietetic Association, 105(12), 1939-1942.
- Panetta, C. J., Jonk, Y. C., & Shapiro, A. C. (2013). Prospective randomized clinical trial evaluating the impact of vinegar on lipids in non-diabetics. World Journal of Cardiovascular Diseases, 3(2).
- Darzi, J., Frost, G. S., Montaser, R., Yap, J., & Robertson, M. D. (2014). Influence of the tolerability of vinegar as an oral source of short-chain fatty acids on appetite control and food intake. International Journal of Obesity, 38(5), 675-681.
- Habowski, S. M., Sandrock, J. E., Kedia, A. W., & Ziegenfuss, T. N. (2014). The effects of TeacrineTM, a nature-identical purine alkaloid, on subjective measures of cognitive function, psychometric and hemodynamic indices in healthy humans: a randomized, double-blinded crossover pilot trial. Journal of the International Society of Sports Nutrition, 11(1), 1-2.
- Cade, R., Conte, M., Zauner, C., Mars, D., Peterson, J., Lunne, D., ... & Packer, D. (1984). Effects of phosphate loading on 2, 3-diphosphoglycerate and maximal oxygen uptake. Medicine and Science in Sports and Exercise, 16(3), 263-268.
- Bellinger, P. M., Howe, S. T., Shing, C. M., & Fell, J. W. (2012). Effect of combined-alanine and sodium bicarbonate supplementation on cycling performance. Medicine and Science in Sports and Exercise, 44(8), 1545-51.
- Lindh, A. M., Peyrebrune, M. C., Ingham, S. A., Bailey, D. M., & Folland, J. P. (2008). Sodium bicarbonate improves swimming performance. International Journal of Sports Medicine, 29(6), 519-523.
source Bodybuilding.com Articles http://ift.tt/21SXknI
No comments:
Post a Comment