A few weeks ago I was honored to be asked by Coach AJ Morrison of Multisport in Motion, and Cory Churches of the Mid-Atlantic USA Triathlon Council to help conduct a female specific endurance nutrition talk for female athletes in the Washington DC area. We held the event last week, at one of the fantastic DC libraries. It’s been been quite a while since I’ve done a power point presentation (maybe 3 years ago when I taught at Lane Community College), but I felt like this presentation warranted it.
In the past (until maybe the past 5-10 years), the majority of the exercise and nutrition based scientific research has been designed with men as the subjects. This is not to say that researchers are sexist or were purposely ignoring us. I believe the main reason is, young men were more accessible, and researchers didn’t necessarily think that women were that much different. We all need calories, the same macro and micronutrients (in different amounts though), and our bodies are similar physiologically. That’s the sticking point-similar, not the same.
Let’s talk physiology first, then I’ll touch on macro and micronutrients in the next post. As any female, or boyfriend/husband will attest to, we have certain physiological processes that can greatly effect our body and moods. Yes, I’ll say it, I’m talking about our menstrual cycles. Not everyone’s favorite topic, but since I believe in giving the facts and talking straight to the point, I won’t sugar coat things. Both men and women have sex hormones, the difference being, women’s hormones fluctuate quite a lot more the men’s do. Women have both high and low hormone cycles that as they increase and decrease, cause changes in our metabolism, glycogen and plasma levels and how we feel and perform.
Let’s break it down:
Estrogen/Progesterone: Female sex/steroid hormones produced primarily in the ovaries
The Menstrual Cycle:
28 Day Cycle, broken into 2×14 day cycles
- Day 1 (first day of period) through Day 14
- This is the low hormone phase of your cycle and has been shown to lead to improved endurance performance. Improved endurance comes from:
- from a lower body temperature
- decreased blood plasma (greater ability to get oxygen and nutrients to cells
- Greater glycogen storage can occur here and less reliance on protein as a fuel source
- Ideally, this is where you want to be for racing, but realistically, who wants to have a period during a long race like IM?
- Try to schedule your “quality” and “key workouts” here in this phase.
- Days 15-28-You will have a surge in estrogen, causing ovulation, followed by a surge in progesterone-this is called the high hormone phase.
- If you are on an oral contraceptive, you will always be in a high hormone phase, even in your placebo week.
- This high hormone phase has some negatives. While you don’t have your period which is nice, you have:
- An increase in your core body temperature, which can lead to greater sodium loss
- pre-menstrual syndrome-headaches, fatigue, bloating
- Blood plasma drops, making muscles fatigue more quickly and lessening tolerance to heat-there has been shown to be an 8% drop in blood plasma during this time. This makes our blood thicker, and harder to get oxygen to our working muscle cells.
- Greater reliance on protein-during long distance racing and recovery
- Some may not be able to complete their workouts as planned-fatigue more quickly, paces you normally hold are harder, etc.
- Some research has shown decreased lactate threshold during this phase
- Progesterone promotes protein catabolism (muscle breakdown), so making sure you’re fueling post workout/race with enough protein, in the proper window is key
- While these are negatives, higher levels of estrogen do have a key benefit for women:
- Estrogen has been known to reduce carbohydrate oxidation (burning) and increase free fatty acid availability. This means you can use more fat as fuel, making this a potential benefit for long distance events. So while we all like to complain about having getting our periods, the fact that we have greater amounts of estrogen vs men, makes our bodies better at handling longer distance events.
- That being said:*During high intensity events like 5-10k’s or sprint/olympic triathlon, the opposite is true, and you might need to take in additional carbohydrates. At least 30-50g of carb per hour (for things over the 60-90min period).
Take away for the athlete:
- Try to race or schedule quality workouts while in the follicular phase/on your period-I know it seems counter intuitive-but your body is better equipped for endurance with lower body temp, thinner blood plasma and the ability to store more glycogen.
- If you on a contraceptive, or do not have your period/luteal phase:
- Increase your salt intake in the few days prior to a race.
- Make sure you are drinking a sports drink, or a diluted sports drink vs water. If you do not drink a sports drink, an electrolyte tab is crucial.
- Make sure you are recovering with protein-20-30g in the 30min post exercise. This will help prevent muscle catabolism from progesterone.
- If you are racing long, your body will rely more on fatty acids (you still need carbs though), however if you are racing shorter high intensity races, you need to make sure you are consuming enough carbs pre, during and post exercise.
- There are some female specific nutrition products on the market today. Some may have merit, others are more of a marketing ploy. If you’re curious, look at the ingredients and compare to a standard sports nutrition product. See if you see any differences, or if you don’t really see any. Following the guidelines listed above will help you succeed, no matter what products you use.
- Just because you do or don’t have your period for a large build week or race, should not dictate or allow you to make excuses for not having a good day. Use it as a piece of education, to start to see correlations between your energy, recovery, etc. around your period. I don’t want you thinking “oh no, I’m in the luteal phase, I’m going to go slower now.”
I’ll continue in the next blog on energy needs, plus specific vitamins and minerals females need to be more aware of. Stay tuned.