CYCLE TRAINING - Printer Friendly - Muscle & Fitness Hers

CYCLE TRAINING

Besides determining the fertility process, the menstrual cycle affects the female system in many other ways. Here's how to alter your diet and training as you go with the flow

By Jordana Brown | Illustration by Alicia Buelow

There's a reason why women are sometimes not ideal research subjects in certain areas of physiological study. It has nothing to do with gender bias or stereotypes of female personality, such as a tendency toward hysteria, argumentative nature and constant mind-changing. Researchers in the past have tended to avoid using women as subjects in their experiments simply because the continual cascade of natural chemicals that constitutes the menstrual cycle makes it incredibly difficult to produce correct and consistent results.

That offers some idea of how powerful the menstrual cycle is - it pretty much affects every aspect of a woman's makeup, from her psychology to her podiatry. And that includes, of course, her lean muscle mass, her ability to burn carbs and her rate of perceived exertion during exercise. Yet it's also commonly understood that exercise can have powerful effects on the menstrual cycle; this can range from women who work out too hard, lose too much bodyfat and stop menstruating to the other end of the spectrum where women try to use exercise to limit the pain of cramps. Our goal is to show you that by altering your training and diet to accommodate certain biological changes inherent to the cycle, you can increase your success in the gym, lending a new spin to the word periodization. Here's a guide to the "when and how" tweaks you should incorporate in your fitness regimen as you proceed through your monthly cycle.

Days 1-4: Menstruation
Although many women consider it the end of their cycle, period time is biologically considered the beginning. Levels of the two primary hormones involved in the menstrual cycle (estrogen and progesterone) have dropped, signaling the uterus to contract to shed its lining, or endometrium. Those contractions are the dreaded cramps, which some women feel more strongly than others.

>> Training Tips: It has long been rumored that aerobic exercise can help combat menstrual cramps. Certainly it makes physiological sense, even if hard scientific data is currently lacking. Cramps are caused primarily by chemicals called prostaglandins, which are produced by the endometrium as it's being sloughed. The prostaglandins encourage the uterus to contract more strongly, which can severely constrict blood flow to the uterine muscle, depriving it of oxygen and causing extreme pain. A hard cardio session reverses that effect by dilating blood vessels, allowing all the muscles in your body to receive plentiful supplies of oxygen. In addition, cardio produces endorphins, the feel-good brain chemicals that are related to runner's high. Add half an hour of high-intensity cardio to your training on the first two days of your period. Repeat on days you still feel crampy.

>> Diet Advice: Although the mechanism is still debated, dosing with zinc before the onset of menstruation appears to prevent cramps. According to a paper published in the journal Medical Hypotheses, case histories indicate that taking 30 mg of zinc 1-3 times a day anywhere between one and four days before your period starts can relieve all cramping. That's not exactly conclusive scientific data, but it might be worth a try, especially if cramps interfere with your training schedule.

Days 5-13: Follicular Phase
Roughly a week, give or take, into the menstrual cycle, menstruation ends and estrogen levels begin to rise. In the ovaries, somewhere between seven and 15 follicles are triggered to mature into ova (or eggs). One (or occasion-ally two) becomes dominant and is released, while the others simply die.

>> Training Tips: Studies, such as one published in the American Journal of Physiology - Regulatory, Integrative and Comparative Physiology in 2006 that examined glycogen usage in the various phases of the menstrual cycle, have repeatedly found that during the follicular phase, carbohydrates are burned preferentially during exercise. This means glycogen stores are depleted more quickly than at other times of the month, so it's a good time to incorporate high-intensity interval training (HIIT) into your regimen. This type of training allows you to really crank up the intensity, which in turn further depletes glycogen stores and turns you into a fat-burning machine. HIIT also increases resting metabolism after training, so you burn more calories the day after your HIIT workout than after a regular one. That, too, really boosts fat-burning.

>> Diet Advice: Don't go crazy, but because your body is going to carbs first when it needs to fuel itself, you can eat more carbs during this phase than you might normally. Still, it's important to your overall health that the vast majority of your carbs be of the whole-grain and fibrous varieties (whole-wheat bread, oatmeal, fruits and veggies). Limit fat intake in these weeks since you're going to be burning those carbs preferentially anyway.

Day 14: Ovulation
Not a phase but rather a dividing point between the follicular and luteal phases, ovu-lation occurs when the dominant ovum is expelled from the ovary. It's accompanied by a staggering spike in estrogen levels.

Days 15-28: Luteal Phase
Immediately after ovulation, the follicle, which incubates and then bursts to expel the ovum, transforms into a biologically active structure called the corpus luteum. It begins to churn out progesterone, which acts on the endometrium, making it cozy for potential implantation of an embryo. Progesterone also elevates basal body temperature and is the primary guilty party for all the symptoms of premenstrual syndrome: bloating, moodiness, acne flare-ups, etc.

>> Training Tips: In a 2003 study published in the European Journal of Applied Physiology, researchers measured a slew of metabolic markers in a group of exercising women at different phases in their menstrual cycles. They found that when the women were in the luteal phase, their body temperatures were higher, they had consistently higher heart rates (10 beats per minute higher) and greater rates of perceived exertion, which means the cardio exercise they did felt more difficult to perform than in the follicular phase. They also found that, based on the metabolic markers they measured, the body depends more on fat for fuel during the luteal phase. Therefore, it makes sense to work out at a reduced intensity but for longer periods to increase fat-burning during this phase.

Another key study, conducted at Southwest Missouri State University (Springfield), found that women had greater power and strength and were less fatigued by the end of a weight-training session during the luteal phase than in the follicular phase. To take advantage of that, plan heavier workouts with more power moves during the last two weeks of your cycle.

>> Diet Advice: A study published in the Brazilian Journal of Medical and Biological Research found that - perhaps as a result of the increased basal body temperature experienced during the luteal phase - women who exercised during that phase had an increased sweat rate. Be sure to drink enough water and maintain electrolyte balance.

In addition, because you burn more fat during this phase, you should consume more fat and less carbohydrate. Rather than just pounding fat in any form, focus on getting healthy fats from sources such as salmon, nuts (particularly walnuts) and avocados.

We women have an average of 480 periods in our lifetimes. As a part of our physiology, it only makes sense that we need to take these periods into consideration as we attempt to better ourselves physically. Take a close look at the information we've presented here - we hope it will help you learn to work with your cycle as you progress toward your training, nutrition and body-sculpting goals.

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