Tag Archives: fitness science

The Way of the Antioxidant

It always seemed so irresistibly simple. Oxidation = bad, therefore antioxidants = good. Free radicals(any atom or molecule that has a single unpaired electron in an outer shell, making it highly reactive and unstable) have long been seen as the “bad guys” going around our body and causing oxidative damage, by “stealing” electrons from other atoms, leading to aging and disease. This in turn can lead to a chain reaction with the atoms and molecules that had their electrons “stolen” from them becoming free radicals themselves, trying to steal electrons from other atoms.

In comes the police, uh, I mean the antioxidants to put a stop to this mayhem. Antioxidants protect the body’s tissues by donating their own electrons to the free radicals, neutralizing the threat. We actually produce our own antioxidants: glutathione peroxidase, and superoxide dismutase, among others. We also get antioxidants through our diet, such as vitamin C(ascorbic acid), vitamin E(actually a family of chemically similar fat-soluble vitamins), and beta-carotine(and other carotenoids), among so many others. Even the non-vitamin phytochemicals in many plant foods often have antioxidant effects(by definition, vitamins are absolutely essential for the body to function properly, while phytochemicals are not, though at least some of them are beneficial for health).

So taking large amounts of antioxidant supplements would obviously protect the body even more than getting smaller amounts from food, right? Wrong! Indeed, let’s look at the results of a study done on athletes who took antioxidant supplements, people whose muscles are under a great deal of oxidative stress during exercise.

Does antioxidant vitamin supplementation protect against muscle damage?
McGinley C, Shafat A, Donnelly AE.
Source

Department of Physical Education and Sport Sciences, University of Limerick, Limerick, Ireland.

Abstract

The high forces undergone during repetitive eccentric, or lengthening, contractions place skeletal muscle under considerable stress, in particular if unaccustomed. Although muscle is highly adaptive, the responses to stress may not be optimally regulated by the body. Reactive oxygen species (ROS) are one component of the stress response that may contribute to muscle damage after eccentric exercise. Antioxidants may in turn scavenge ROS, thereby preventing or attenuating muscle damage. The antioxidant vitamins C (ascorbic acid) and E (tocopherol) are among the most commonly used sport supplements, and are often taken in large doses by athletes and other sportspersons because of their potential protective effect against muscle damage. This review assesses studies that have investigated the effects of these two antioxidants, alone or in combination, on muscle damage and oxidative stress. Studies have used a variety of supplementation strategies, with variations in dosage, timing and duration of supplementation. Although there is some evidence to show that both antioxidants can reduce indices of oxidative stress, there is little evidence to support a role for vitamin C and/or vitamin E in protecting against muscle damage. Indeed, antioxidant supplementation may actually interfere with the cellular signalling functions of ROS, thereby adversely affecting muscle performance. Furthermore, recent studies have cast doubt on the benign effects of long-term, high-dosage antioxidant supplementation. High doses of vitamin E, in particular, may increase all-cause mortality. Although some equivocation remains in the extant literature regarding the beneficial effects of antioxidant vitamin supplementation on muscle damage, there is little evidence to support such a role. Since the potential for long-term harm does exist, the casual use of high doses of antioxidants by athletes and others should perhaps be curtailed.

Okay, so they don’t prevent oxidative damage to muscles, but can vitamin C at least improve athletic performance?

Effect of vitamin C supplements on physical performance.

Braakhuis AJ.
Source

US Olympic Committee, Sport Performance, Olympic Training Center, Chula Vista, CA 91915, USA. andrea.braakhuis@usoc.org

Abstract

Vitamin C is an essential component of the diet and may reduce the adverse effects of exercise-induced reactive oxygen species, including muscle damage, immune dysfunction, and fatigue. However, reactive oxygen species may mediate beneficial training adaptations that vitamin C attenuates; indeed, from a total of 12 studies, vitamin C in doses >1 g·d(-1) impaired sport performance substantially in four of four studies, possibly by reducing mitochondrial biogenesis, while a further four studies demonstrated impairments that were not statistically significant. Doses of ∼0.2 g·d(-1) of vitamin C consumed through five or more servings of fruit and vegetables may be sufficient to reduce oxidative stress and provide other health benefits without impairing training adaptations.

It appears that supplemental vitamin C impaired performance. The general idea here for why mega-doses of vitamin C and other antioxidant supplements are not protecting tissues or enhancing performance is that not all oxidation reactions are harmful; they are used in many metabolic reactions, for cell communications and are important for the immune system. So if you effectively shut down oxidation with a flood of antioxidants, you may be interfering with some important chemical reactions in your body, and doing more harm than good. Vitamin C isn’t just an antioxidant – it is needed for collagen production and immunity and not getting enough results in a serious deficiency disease called scurvy. Scurvy is very rare in the developed world, and only a small daily dose(60mg) of vitamin C is necessary to prevent it.

The best way to get antioxidants. Source: Wikipedia

The best way to get antioxidants. Source: Wikipedia

Okay, then maybe, just maybe a powerful antioxidant like beta-carotine can protect smokers, who are exposing themselves to a lot of oxidative damage through the act of smoking:

Beta-carotene in multivitamins and the possible risk of lung cancer among smokers versus former smokers: a meta-analysis and evaluation of national brands.

CONCLUSIONS:

High-dose beta-carotene supplementation appears to increase the risk of lung cancer among current smokers. Although beta-carotene was prevalent in multivitamins, high-dose beta-carotene was observed among multivitamin formulas sold to promote visual health.

So far, it doesn’t look like antioxidant supplements are beneficial for anyone’s health. Beta-carotine, in particular, may even increase lung cancer risk in smokers.

This doesn’t mean that antioxidants are themselves bad for you. It just means you are better off getting them from food, where they may interact with other chemicals in the fruits and vegetables they naturally coincide with in a manner that makes them relatively harmless and likely beneficial.

Antioxidants do provide some protection, but that’s not the whole story. It’s long been thought that fruits and vegetables are beneficial largely due to their antioxidant content. This may still be true in part, but the phytochemicals in them may have other ways of protecting our health in ways science is still trying to figure out. Antioxidant content may be a proxy measure of protective phytochemical content, since many if not most phytochemicals tend to have antioxidant effects. Blueberries, with a very high antioxidant content and some possible brain-protecting effects, are a good example of this.

Good health means having a good balance between antioxidants and oxidation reactions, which taking large doses of antioxidant supplements interferes with.

You don’t have to stretch!

It was, for a very long time one of the biggest sacred cows in all of fitness: You have to stretch before and after exercise to improve performance and prevent injuries. This idea has been drilled into our brains for years, as children in gym class, and now as adults at gyms and fitness classes. “You have to stretch” – It is often stated as a religious mantra. Just about all of us believed this, myself included. The only people opposed to stretching were considered heretics, or more likely just lazy or idiotic.

Luckily, there are no sacred cows in science. If an idea doesn’t stand up to scrutiny, if there is no evidence to support it, it gets slaughtered. Thanks to many scientific studies done on stretching, we now know it doesn’t improve athletic performance or prevent most injuries. Don’t believe me? Here it is:

The impact of stretching on sports injury risk: a systematic review of the literature.

RESULTS:
Stretching was not significantly associated with a reduction in total injuries (OR = 0.93, CI 0.78-1.11) and similar findings were seen in the subgroup analyses.

Don't worry, you won't become as stiff as these guys if you don't stretch.

Don’t worry, you won’t become as stiff as these guys if you don’t stretch.


Wow! In spite of this, telling people they don’t need to stretch is considered a radical or even harmful idea even by some personal trainers. So many people continue to advocate this practice, even though the science isn’t there to support them. Next time someone tells you you have to stretch, politely show them the evidence that demonstrates there are no benefits from regular stretching. Now this is just about stretching when it comes to general exercise, I don’t think this applies to physical therapy. And “warming up” isn’t the same thing as stretching; warming up does improve performance and may prevent injuries, especially if the temperature is cold. Don’t worry, if you don’t stretch you won’t become as stiff as a statue.

Stretching may even be harmful if done before some types of exercise, since it may lead to overpronation and injury. It is important to note that Running economy is negatively related to sit-and-reach test performance in international-standard distance runners.

Because of the weight of the evidence, I almost never stretch and I do not advocate it. All the juggling and joggling I do is made possible through a fitness regimen that excludes stretching. For similar reasons, I don’t do yoga, which I consider overrated(relative to the hype), although I don’t doubt it helps many people because just about any exercise is better than no exercise. I’m not saying yoga is inherently bad, just that it doesn’t have much to offer me. If you enjoy it and you benefit from it, I have no argument with you. If you don’t like juggling, that’s fine too.

Whatever you do, a fitness program based on fact, and science is going to be better than a fitness program based on pseudoscience.

Photo source – C.P the Wild Juggler

The effects of air pollution on exercise

How air pollution affects exercise performance doesn’t get as much attention as it deserves. It is a rather complex subject, although it seems rather intuitive that the more polluted the air, the worse it is for exercise. Although air pollution is everywhere, it is far worse in urban centers, with most of it coming from vehicle exhaust.

On this issue, it appears that science agrees with our intuition. According to this study – Subclinical Effects of Aerobic Training in Urban Environment, which compared people trying to improve their aerobic fitness in urban and rural settings, both groups became equally fit, though reaction times were better in rural settings and the urban exercisers had significantly higher levels of inflammation markers(exercise even in a non-polluted area can cause inflammation, it’s just worse in polluted areas).

I don’t believe the lesson to be learned from this is to not exercise if you live in a polluted area, unless you have respiratory disease, but rather to be more cautious or try to seek out an area with cleaner air to exercise if possible.

Also, I think it could be possible to prevent the inflammation caused by pollution by eating better. Some foods have a pro-inflammatory effect, like food with a high saturated fat content, as well as fried, roasted and overly processed foods. On the other hand, many fresh fruits and vegetables either have a neutral effect on inflammation or can help prevent it from getting out of control. Curcumin, a natural compound which is found in turmeric(an important ingredient in curry), has potent anti-inflammatory effects. Ginger, a close cousin of turmeric has similar benefits. Leafy greens may also help. Try to get all this from food, not supplements.

Besides this, if you are a runner living in an urban environment, try to stay far away from highways or areas with heavy traffic when running. In my personal experience, it seems that I’ve had to apply more effort when running in polluted areas than in non-polluted areas to achieve my usual pace. Also, the study I cited seems to suggest that air pollution would have more of an effect on jogglers than runners, since air pollution interferes with reaction rates/cognition during aerobic exercise. In my experience, I am more likely to drop the balls in polluted areas.

Do not let this discourage you from exercise, unless you have medical issues.

Lactic acid is not your enemy

The idea that lactic acid causes muscle fatigue and stiffness during exercise is a stubborn one. It has been discredited by scientific research, but many fitness enthusiasts still see lactic acid as an enemy that interferes with performance.

Not only does lactic acid(which in the body is in the form called “lactate”) not cause muscle fatigue, it is actually used as an important fuel during vigorous exercise.

This myth goes back to the early 20th century, but it was fully discredited only recently.

All this begs the question: What is causing the fatigue and stiffness that was once blamed on lactate? According to researchers at Columbia University, it may be caused by overworked muscles leaking calcium, among many other factors. And acidity in general in fatigued muscles may play a role in stiffness and fatigue, it’s just not the lactate causing most of it.

So what’s the solution? The idea of calcium leakage partially causing muscle fatigue doesn’t mean most people should consume less calcium, as this is a vital mineral(it is possible to get too much, and it can cause problems but this is rare). However, and I am just speculating here, maybe ensuring adequate vitamin K consumption can help prevent this a little, since it helps with calcium metabolism, along with making sure you get enough magnesium. Calcium helps muscles contract, magnesium helps them contract as well as relax; if you have too much calcium in your body relative to the amount of magnesium, this can be problematic(in fact, not getting enough magnesium may be detrimental to your heart).

It is relatively east to get enough magnesium if you eat like a rabbit – lots of leafy greens, nuts, and whole grains. Fermented vegetables are an especially good source of vitamin K. If you are taking calcium supplements, it may be a good idea to take supplements that combine magnesium with the calcium, to counteract the potentially negative effects of calcium. Try discussing this with your doctor or pharmacist.

Proper hydration and making sure you are getting the right amount of electrolytes helps too. I don’t think stretching would help, since just because a muscle is stiff doesn’t mean it needs to be stretched. Increasingly, science is showing that stretching is practically useless for most people.

Very thoughtful, science-based post about running shoes. All kinds of claims are made about various types of running shoes, but there is so little science to support these claims. We definitely need better research.

Here is an article I wrote for the online magazine Performance. It’s a brief overview of the limited amount of research there actually is linking shoes to (the prevention/recovery of) injuries. Reading the (limited) research really does get you wondering how manufacturers are able to make their billions selling a unsupported story.

Shoes come in all shapes and sizes, designed for many different activities. Design may be led by market preference, fashion and/or ‘science’. Because of the marketing strategies used in sport and sport products, running shoes have attracted ample claims to support their design and effectiveness. But how much data is there…really?

The word on the street

Seemingly scientific claims determine the marketing, sale, and even clinical prescription of trainers. Manufacturers and sales assistants could probably be forgiven; after all, they are working in a commercial environment. However, many podiatrists, osteopaths, and physiotherapists also recommend specific types of…

View original post 1,058 more words

Vitamin D may improve athletic performance

It may not be the cold air or Old Man Winter’s roar that keeps even seasoned athletes indoors during the winter. According to the scientific literature, vitamin D may improve athletic performance, but only in athletes who are deficient in vitamin D.

So who is most likely to be deficient in vitamin D? Since vitamin D is produced in the body when the skin is exposed to sunlight, it shouldn’t worry people who get at least some sun exposure throughout most of the year, unless they live north of 37 degrees latitude during the winter. The sun’s rays are too weak north of 37 degrees, and it’s even worse if your skin is dark, since melanin can block sunlight.

The elderly also have problems making vitamin D, even if they get sufficient sunlight. Vitamin D(a misnomer, it is actually a hormone) is necessary for calcium absorption, which helps build strong bones, and may also boost the immune system, among other things. Scientists have found links between vitamin D deficiency and certain forms of cancer, but a lot more research needs to be done.

Eating a healthy, varied diet can provide just about all the nutrients the average person needs, but hardly any foods contain sufficient quantities of vitamin D to meet new nutritional guidelines. Even multivitamins fall short of the new guidelines. So it looks like eating food fortified with vitamin D(like milk) or vitamin D supplements may be the answer, for those who live north of 37 degrees latitude from autumn to spring.

A rather interesting possible solution which doesn’t involve supplements is to get some mushrooms(button mushrooms, shiitake, and many other mushroom species, but do not pick any wild mushrooms unless you know what you are doing) and place them in the sun for a few hours. When exposed to sunlight, they will manufacture vitamin D, just like humans, in quantities that are as good as or even better than supplements. This is certainly a wild solution!

I take a 5,000 I.U vitamin D supplement about twice a week during the winter since I am in the north-east U.S. I don’t take them at all during the summer, since I get enough sunlight during that time of year. I take it twice a week since vitamin D is fat-soluble, which means it can be stored in the liver and fatty tissue, unlike water soluble nutrients like vitamin C, which are quickly removed from the body which is why you need to get it every day.

So if you’re an athlete or even if you’re not an athlete, and you feel sluggish and you live in the northern U.S, see if you can get your vitamin D levels checked by your doctor. Or, you can just eat more mushrooms that have been sun-bathed as suggested above if you suspect you’re deficient. Like many nutrients, Vitamin D can be toxic in large quantities, so be careful.

For my fellow vegetarians and vegans – vitamin D-3, also called “cholecalciferol” is not vegan since it is derived from animal sources. However, vitamin D-2, also called “ergocalciferol” is vegan since it comes from plant sources. The type of vitamin D that is in mushrooms is D-2/ergocalciferol.

Awesome new book about fitness

I recently read Alex Hutchinson’s “Which comes first, cardio or weights?“, and found it very helpful. Hutchinson is not just a runner and a journalist, he also has a Ph.D. in physics. The book attempts to answer many commonly asked questions about exercise, and uses a science/evidence based approach to answer them. This is the best, most awesomest approach, in my opinion.

When the evidence isn’t clear, he says so. He is very familiar with the latest scientific literature regarding fitness. It is refreshing to read a fitness book based on science; all too often, fitness/health authors push pseudo-scientific ideas that may be useless or even harmful. It is also refreshing that Hutchinson is not using the book to hawk supplements, exercise equipment or videos, which are often intertwined with the pseudo-science the author is pushing.

Among the questions Hutchinson answers are:

1) How much should I drink to avoid dehydration during exercise?

2) Will stretching help me to avoid injuries?

3) Is it possible to be fat and healthy at the same time?

4) Should I have sex the night before a competition?

5) How should I pace myself for a long-distance race?

6) How can I adjust my chakras so I can run faster? (just kidding! This is NOT in the book!)

Among dozens of other common and uncommon questions. Some of the answers may surprise you. For example, scientific studies suggest that stretching does not help prevent injuries – because of this, I almost never stretch anymore.

Besides not wasting precious time stretching, I’ve found a lot of other information in the book beneficial for my fitness routine. While the book doesn’t cover fitness juggling or joggling, the general fitness information it contains may also benefit fitness jugglers. I highly recommend it. I have no connection to the author.

I also recommend reading the scientific literature yourself whenever you can. It won’t be long before this book becomes dated and certain recommendations may even change over time as new scientific evidence comes in.

Happy juggling!