Posts Tagged ‘metabolism’
I feel that my situation was pretty typical of what a number of female athletes go through. I was prescribed Ortho Tri Cyclen* when I was 17 because I hadn’t had a period for more than two years. Not wanting to put anything artificial in my body and being scared about the hormones, I didn’t actually start taking the pills until I sustained a stress fracture in my foot during my freshman cross-country season at college.
After the fracture, a doctor convinced me that it occurred because my bone density was low. He said my bones were suffering because I didn’t have periods. This was the case because the absence of menses meant that my body didn’t have enough estrogen… and estrogen was the key to calcium being absorbed by my bones. He told me that my estrogen was low because I ran so much. And he said all this could be corrected by taking the birth control pill because it would supply my body with artificial estrogen that would keep my bones strong.
The Female Athlete Triad- of disordered eating, amenorrhea, and osteoporosis- was a relatively new buzzword ten years ago and doctors, trainers, and coaches were quick to jump to the conclusion that the birth control pill was the easiest, quickest-fix band-aid solution to the most bothersome part of it. I wish that I could say that as a community, sports medicine has made tremendous progress – that doctors, coaches, and trainers know a great deal more about how to address these situations with their athletes, but I don’t really believe it’s much better. Birth control pills are more than ever being prescribed to young athletes (and non-athletes alike) as a quick-fix solution to problems that require a much deeper and more comprehensive look at the whole system.
When I look back at my own situation, I realize that the Doctor made a lot of assumptions in his hypothesis. First, he assumed that my stress fracture was due to having low bone density, though he never measured the density of my bones. In reality it was my training that changed significantly – I had gone from running maybe 40 miles per week on dirt roads in high school in Colorado to running 70+ miles per week in college mostly on pavement.
The other reality about my situation was that running or body fat percentage wasn’t the cause of my amenorrhea. I was always a very active teenager and a “late bloomer.” I played 3-4 varsity level sports during high school. I only had a couple “regular periods” when I was 15 years old and they ceased when I left to be an exchange student in southern Brazil. In Brazil I wasn’t allowed outside of the house alone. It was, by far, the most sedentary I have ever been at any time in my life. And like all exchange students, I gained a few pounds. And yet this is the time in my life when my periods stopped. When I returned from Brazil, I embarked on a 30-day wilderness education course backpacking across Colorado’s San Juan Range. But still my cycle didn’t return.
Over the years I stopped taking birth control twice for several months at time to see if my period would return on its own. Each time I noticed a marked improvement in my mood and digestion, but each time a friend or doctor encouraged me to go back on the pill because I needed it for my bones. I remained on a mono-phasal birth control pill until the age of 25. At that point, my digestive problems and allergies were so bad that I wanted to try anything to alleviate the situation. I read as much as I could find on the subject, scheduled a bone density scan that came back on the low side of normal, and quit the pill for good. It was a liberating feeling!
Eventually, about 7 months later, my cycle returned naturally for the first time in over 10 years. For the first year or two it was not consistent- some months it wouldn’t come, some months it would only last a day. However, the overall trend was one of progress.
Acupuncture has been the single most helpful tool for me in finding hormonal balance and regulating my periods. I highly recommend it!
Birth control pills have always been a subject of much debate for female athletes. It seems like it is the modern-day doctor’s answer to any irregularity in the menstrual cycle. They want you to go on the pill for everything, you bleed too much, your cycle is too short, too long, non-existent… or hey, you have acne? No problem… take this pill. It only gives you a constant supply of synthetic hormones. (!)
Popping a pill is a much easier solution than trying to look into the root cause of the hormonal problem in the first place. What really upsets me is the lack of studies that have been done on the long term side effects of being on the pill and the real lack of studies actually done on athletes.
This latest study finds that women on the pill are “less likely to build muscle” than those not taking it. “You can still gain muscle on the pill, you just have to work harder.” The reason for this is because the pill drops levels of circulating testosterone. For the collegiate athlete, or the competitive athlete this is a serious issue.
My favorite part is at the end of the video:
Q: Should you reconsider taking the pill in light of this study?
A: Probably not unless you are a competitive athlete or body builder.
I was alarmed to find this article about Stevia on the Vegnews website. I eat a fair amount of stevia… ever since the non-bitter types came out a number of years ago. My favorite brand is NuNaturals out of Eugene, Oregon. It really has the cleanest flavor of any that I’ve tried over the years. The maltodextrin doesn’t seem to have any adverse affects on my stomach at all. The new Truvia, however, doesn’t sit as well. I appreciate them trying to cut stevia with Erythritol to give it that granular sugar-like quality, but my system doesn’t do well with sugar alcohol even though Erythritol is much more gentle on my system than Xylitol.
An aside: Erythritol & xylitol, are natural sugar alcohols so they are digested differently than regular sugar and don’t produce the pronounced blood-sugar spike and insulin response… too much of which is linked with diabetes and weight gain. Erythritol is known for having less gastric side effects than other sugar alcohols because it is absorbed in the small intestine while xylitol is absorbed in the large intestine and larger quanities often lead to gas, bloating and a laxative effect. Erythritol, has 5% of the calories of table sugar (.2calories per gram vs. 4 calories per gram) and 70% of the sweetness. So it is almost calorie-free
But back to the sweet stevia leaf…. after reading this article I want to figure out how it affect fertility in women, not just men. ugh. I really don’t want to give up my little white packets. They make cocoa & tea so much more delightful.
READ THE FULL STORY ON VEG NEWS.COM
Does this sugar stand-in stymie hopes for fertility in the future? VN’s resident nutritionist studies the sweet substitute.
By Ilyse Simon
Confused about whether or not switching from sugar to stevia might hurt your chances at parenthood? Your nutritional debate is understandable. Though the Food and Drug Administration approved stevia in December, there’s still some question about how much is really safe, especially if you’re trying to conceive. The short answer is that adding stevia to a cup of tea or coffee each day won’t compromise your health. However, stevia is worth scrutinizing if you plan to use it often or in large quantities.
Stevia is a shrub native to South America with leaves sweeter than white sugar. It’s calorie-free and one of just a few alternative sweeteners for people with diabetes, and the FDA has designated stevia Generally Recognized as Safe. (This is controversial because there are many products deemed “safe” by the FDA that I would never consider consuming, and the FDA has a history of protecting big agribusiness over human health—but there’s an element of truth to this one.) Stevia has been used in other countries for centuries without ill effects. Used to sweeten yerba mate in Paraguay and in Japan to sweeten pickles since the 1970s, stevia—in small quantities—has not been proven harmful. The main concern is that if we mass-market this plant extract as we have with soy, stevia could become a ubiquitous ingredient in everyday packaged foods. If your energy bar, smoothie, tea, and dairy-free ice cream are all sweetened with stevia, that might be more than is considered healthy.
North Americans, in general, still think more equals better, and tend to go to extremes when we find something we like. Again, it’s similar to the soy story: Asian cultures eat moderate amounts of soy daily in whole-food forms without negative consequences; Western cultures have processed and refined soy into isolated protein components, added it to highly processed energy bars, and continue scarfing them down like health foods. This is where the problems lie. The specifics on stevia show that high amounts affect male reproductive health with reduced sperm counts and possible infertility. In some laboratory studies, stevia acts on a cell’s DNA to cause unwanted mutations and may promote cancer. In other studies, large amounts of stevia interfere with normal carbohydrate metabolism. Recently, the Center for Science in the Public Interest lists stevia as an additive that people should “try to avoid,” but maintains that small amounts are probably safe.
The bottom line is that a little is probably fine, but a lot is not. That’s advice for almost any situation. One or two cups of coffee with stevia is not raising concern amongst researchers. It’s the scenario where stevia sweetens diet soda, fruited waters, and every piece of chewing gum stuck to your shoe that is of concern. Keep your diet clean, eat lots of fruits and veggies, go ahead and ditch the tighty-whiteys, and your fertility will likely be fine.
To go long distances, especially those longer than 10,000m, runners place a premium on relying primarily on aerobic metabolic pathways during the majority of the run. Runners who are capable of doing this rely mainly on fat for the majority of fuel, enabling them to limit the usage of carbohydrate. Carbohydrate storage is finite, but fat storage is, from a practical standpoint, limitless. The higher reliance on fat enables long-distance runners to run very long distances. It also enables them to preserve carbohydrate for moments during the race when they require fast acceleration (e.g., at the end of the race or while passing another runner). According to one study, only 2 to 7 percent of the total energy burned in aerobic activity is derived anaerobically.24 A small amount of carbohydrate is used even when maintaining aerobic activity, so distance runners must develop strategies for delivering carbohydrate during the run. A failure to do so will result in either low blood sugar or low muscle glycogen, both of which impair endurance by leading to premature muscle fatigue.
Keeping this in mind, distance runners must consider the following nutritionally relevant factors for their sport.
Long-distance runners are at risk of amenorrhea, low bone density, and stress fractures. The distances that these athletes run weekly to train may predispose them to stress fractures, despite the potential stimulating impact of running on skeletal mass.25 Although stress fractures occur more frequently in women runners than in men, all runners should ensure that their calcium intake is adequate to reduce the risk of fracture. Female runners are at higher risk of stress fractures because hard endurance training is often associated with cessation of the menstrual cycle. The reduced estrogen associated with amenorrhea is linked to lower bone density. Therefore, runners who experience either primary or secondary amenorrhea should seek appropriate medical advice to determine if rea son able steps can be taken to return to normal menstrual status.26
Female runners should take the following steps to reduce the risk of osteoporosis:
Consume calcium (1,500 milligrams per day) from food or a combination of food and supplements.
Avoid overconsumption of protein because excess protein is associated with higher urinary calcium losses.
Control the production of stress hormones (particularly cortisol) by maintaining hydration and blood sugar during exercise.
Avoid overtraining, which is associated with amenorrhea.
Inadequate energy intake is a red flag that the intake of vitamins and minerals may also be low. A study comparing the nutrient intakes of trained female runners who were amenorrheic, oligomenorrheic, or menstruating normally found clear nutrition differences between these groups, despite being matched on height, weight, training distance, and body fat percentage.27 The runners who were not menstruating had zinc intakes well below the recommended level of intake and lower than those found in the runners who had normal menses. In addition, the runners who had normal menses had higher intakes of fat and a more adequate total energy consumption. This suggests that high-carbohydrate diets, which are preferred for optimal performance, make it more difficult to consume the needed level of energy because carbohydrates have a lower caloric density than high-fat foods. Therefore, athletes should concentrate on consuming more food when carbohydrates constitute the main energy source. A failure to menstruate normally is a strong risk factor in the development of weaker bones and resulting stress fractures. Female runners have good cause to be fully aware of the adequacy of their energy and nutrient intakes because almost no injury is more frustrating or potentially career ending than the development of frequent stress fractures. Endurance runs require enormous amounts of energy (a marathon requires about 2,900 calories); they cannot be adequately trained for or run without an adequate total energy consumption. Food intake strategies, including eating snacks between meals and consuming snacks or sports beverages before, during, and after exercise, are important for ensuring that fuel consumption matches need.
Elite runners depend heavily on both fat and carbohydrate for fuel to accelerate and vary speed over the course of a long-distance race.
Surveys of distance runners confirm that total energy and carbohydrate intakes are below the recommended levels, suggesting that runners must make a concerted effort to consume the recommended amounts before, during, and after exercise.28,29 In a case study assessing the nutrient intake of an ultraendurance runner during a race, it was found that if the pre-event and during-event guidelines for food and beverage are followed, then athletes will have sufficient energy and fluids to successfully complete the event.30
Tapering activity before a competition improves competition performance.31 It does so by increasing glycogen stores, but it also makes the runner calmer, which gives the athlete an improved economy of running motion that enhances endurance. The importance of tapering exercise and of carbohydrate loading before an important event cannot be overemphasized.
Fluids are crucial. Fluid consumption should be on a fixed time schedule (every 10 to 15 minutes) to avoid underhydration and thirst. Perhaps no single factor is more important for ensuring a long-distance runner’s success than maintaining an optimal hydration state. Athletes should drink now, drink again in 10 to 15 minutes, and when they believe they’ve had enough, they should drink
more. Of course, the type of beverage consumed is also important.
A great deal of body heat is generated over the course of an endurance run, and this heat is liberated through sweat evaporation. Studies strongly suggest that a 6 to 7 percent carbohydrate solution with electrolytes is most effective in maintaining exercise endurance.31 It has been firmly concluded that acute heat exposure is detrimental to muscular endurance.32 Therefore, long-distance runners should develop the habit of frequent fluid consumption to maintain body water status, whether they are thirsty or not. A fluid intake of .5 to 1 liter per hour is sufficient to prevent significant dehydration in most athletes in mild environmental conditions, but a greater intake of fluids is needed for athletes running at higher intensities or in more severe environmental conditions in order to avoid heat stress.33
Distance runners typically have relatively low body fat levels. Successful long-distance runners are commonly thin, and this body profile may be advantageous to them in dissipating heat during long runs.34 However, since very low body fat levels are associated with amenorrhea, female athletes should seek a balance between low body fat levels and normal hormone function.
A critical factor in the performance of all endurance athletes is iron status, and evidence exists that endurance runners have reduced hemoglobin, hematocrit, and red blood cell counts when compared with strength and mixed-trained athletes.35 Iron status is sufficiently important that one of the more common illegal ergogenic aids used by endurance runners is erythropoietin (EPO),36 which stimulates the production of red blood cells, thereby enhancing oxygen-carrying capacity.37 Iron is an essential oxygen-carrying component of hemoglobin (red blood cell iron), myoglobin (muscle cell iron), and ferrochromes (oxygen-carrying enzymes essential for making ATP) in the mitochondria. It appears that hemoglobin status is of highest priority, so iron from other cells is cannibalized to support a normal hemoglobin production when iron stores (ferritin) and intake are inadequate. Therefore, a standard blood test measuring hemoglobin may appear normal while other iron-containing cells are depleted. For this reason, it is important that blood tests in endurance athletes always include a measure of ferritin, which should be at the level of a minimum of 20 nanograms per deciliter. Besides having an inadequate dietary intake, which is most common in runners who do not eat red meat or who are vegetarian, there are several other common causes of low iron status in runners:38-40
Excess iron loss in sweat
Excess loss of blood through the GI tract
Excess loss of blood in the urine (hematuria)
Excess menstrual blood loss in female runners
Poor absorption of iron
OK, I admit it…. I watch the Biggest Loser. It is the only reality TV show that I’ve ever really watched and certainly the only the one I’ve been hooked on. And yeah… I’ve been there since the beginning. In all fairness, we cancelled our cable last year- so I had to give up my food network addiction (Alton Brown, I miss you!) and my love for HGTV. I love making fun of the mainstream advice that the trainers give, not to mention the mini-commercials that riddle the episodes.
Like Bob really eats Quaker’s Weight Control Oatmeal EVERY day for breakfast. At least in this week’s pop quiz, all the remaining contestants knew the calorie equivalent of a pound (3500 Kcal). Before this show, I’m sure most of them stayed as far away from that knowledge as possible.
The way the producers have stretched this show into a two-hour infomercial is almost inspirational. And yeah, the writer’s strike probably had something to do with it, but it is definitely the most brilliant marketing move ever made by 24-hour fitness.
The irony of Ian and I watching this is certainly not lost on me… he is pretty scrawny and I am not exactly huge….we’re both underweight according to our BMIs. We joke about him going on a show for Biggest Gainers, where they take skinny guys and see who can gain the most muscle.
But seriously, there is something very inspirational about the positive underlying message. These people are taking their life in their hands. They are doing something, they are motivated, they are making changes. I also can’t believe how hard these obese contestants can push themselves (you know the casting crew must do some serious testing on these people to make sure they can handle that type of physical activity). And I do love the before & afters.
I am addicted to the Biggest Loser the same way I love shows about remodelling and flipping houses. (I would watch Extreme Home Makeover, but Ian won’t have it). In the end there are worse things than being left with a compulsion to do core exercises and scrub the bathtub.
The media, scientists, and health experts are always telling us that things are getting sweeter… Food that is. There is no way to get around it: sweetness is seductive. We love it. We crave it. And then we seemingly become addicted to it. Why?
One explanation for the palatability phenomenon is biological: Our foraging ancestors were attracted to sweet food because it was a sign that it was edible and good source of much-needed calories in a world where food was scarce and the next meal uncertain.
One thing metabolically certain is that when we ingest sugar (or starches) our bodies immediately respond by flooding our bloodstream with insulin. Insulin is the magical hormone that is responsible for storing that immediate energy in our fat cells (as long as it isn’t needed for immediate muscle repair or fuel for exercise). Increase the insulin, and you increase amount of fat stored. It is a brilliant system, as long as your goal is not to eat large amounts of simple carbohydrates and lose weight. I actually recently read an article about the eating disorder associated with Type 1 Diabetics, where they purge calories by skipping or under-dosing their insulin shots. This obviously is not a good thing- and these girls are suffering serious medical complications and premature death as a result.
Then there is the conspiracy-theorist’s explanation of why the world is getting sweeter…and more obese. Sugar sells. And it is addictive. Food manufacturers want to create ever more palatable offerings to lure and keep customers coming. So hence, we have an entire industry based on snack foods and soft drinks. And this cycle continues to fuel our need to satisfy those sweet and salty taste buds. Have you tried to find even jarred pasta sauce without sweetener? What is sugar doing in marinara? Producers even sweeten deli meat…It gets quite ridiculous when you stop and actually look at the labels.
1. Foot Strike Hemolysis—red blood cells are destroyed by runners’ feet pounding on the ground. You literally squish them as you strike the ground. This loss can be even more intense at altitude.
2. Sweat & Urine—small amounts of iron are lost in sweat and urine and these amounts can add up over time and worsen in hot weather.
3. GI & Menstrual Bleeding—small amounts of iron are lost due to bleeding in the gastrointestinal tract that is common with intense training/racing, while larger amounts can be lost through a regular menstrual cycle. If your cycle is causing you to lose more significant amounts of blood due to an extended length, heavier flow or increased frequency, you should report this to your doctor so that she can try to find the cause.
4. Low Iron Intake—runners who follow the traditional high-carb/low-fat endurance diet often do not consume much red meat, which is the best absorbed source of dietary iron. Many runners also tend to under eat in an effort to maintain an artificially lower weight. There is evidence that this type of calorie restriction lowers metabolic functioning and over the long term may lead to a sluggish thyroid or hypothyroidism.
Hematocrit— the percentage of red blood cells in the blood
Ferritin— the body’s stored iron (primarily in bone marrow, liver, and spleen)
Iron-Deficiency Anemia—clinically low hemoglobin or hematocrit levels
(B12 deficiency can cause another type of anemia, more common in vegetarians than meat eaters because B12 is difficult to get from a vegan diet)
Iron Depletion—low ferritin levels (for running purposes 30)
What exactly is ferritin again?
For one thing, different people seem to require different levels to feel good. One athlete may perform best as long as her ferritin is over 40, while another may require double. When fine-tuning for performance enhancement, it is best to track ferritin levels over time, that way you can get a baseline level of what might be normal for you. Unfortunately, few people think to go in for blood tests when they are feeling fine. Some sports medicine docs and coaches like an athlete’s ferritin to be above 100. It is commonly accepted in the running community that a score under 30 means you should be pumping some iron into your system, in whatever form necessary.
Serious female runners should have their iron levels checked a minimum of twice (preferably four times) per year. Competitive male runners should be tested annually, and those with a history of iron depletion (or vegetarians) should be tested at least twice per year. To ensure consistent results, always have your blood tested before running (i.e., when you are well-hydrated), because dehydration will make your iron levels appear higher than they are. Again, the major iron status tests of interest to runners are: hemoglobin, hematocrit, red blood cells and ferritin. And, depending on how savvy your doc is, you may have to specifically request the ferritin to be checked. Unfortunately, it is still not a commonly performed test by many family practitioners.
More on iron supps and common signs of deficiency in another post.
On the bright side, the rain does make it much more pleasant to bake. It is hard to believe that we’ve had such a dreary August. It is usually the only consistently nice month in the Northwest. Classes start on Monday and most of the team is back already. They had their camp over the weekend and we have our first practice on Friday. And just like that *** my weekends are booked until Christmas break.
Yesterday we went out to Sauvie Island to run the loop, to celebrate the end of our Sunday running freedom. It was beautiful, but it actually sprinkled on us for a little while. To be honest, I love the sun- but I don’t live in Oregon to put up with 90 or 100 degree weather like we had last summer. Ian often laughs and says that I “have the narrowest temperature range he’s ever seen.” It’s true. I HATE being hot- I absolutely wilt- and I get cold easily.
My tolerance, however, has been so much better since starting the thyroid medication. The difference was dramatic and the first thing I noticed. I used to get COLD. REALLY COLD. It would seep in and settle deep inside and I would feel like I was going to die. I know that sounds terribly over dramatic, but I did actually feel like I would die. The only way to warm up was to submerge myself in a boiling hot bath.
I’m not saying that the thyroid meds turned me into a Polar Bear. I’m still not like one of those middle aged men who wear t-shirts when it’s 40 degrees and refuses to don close-toed shoes. The pills just took the edge off. I still get cold (more easily than most), but I don’t feel like it will kill me.
Actually, I’ve been lucky with the thyroid medication- I haven’t had to tinker with the dosage at all since starting it last November. I know that is pretty rare and my good friend has had a much harder time. I’m still holding out hope that the Celiac caused the elevated thyroid antibodies and if I remain gluten free for long enough, maybe my thyroid will self correct. I know it is a long shot and I’m not into the idea of going off the thyroid medication in the mean time, so I’m not sure if it would know to correct if I’m medicating it? Maybe that is faulty logic?
There seems to be a growing number of people who think that athletes may, in part, cause the thyroid disorder from overtraining and undereating. It is an interesting theory.
I’m also holding out hope that my long time battles with anemia will go away with my gluten free lifestyle. So far, it’s a no go…. but iron is another story altogether…