Health, Nutrition, Podcast, Training

Triathlon training and nutrition considerations for female athletes with Stacy Sims, PhD | EP#105

 February 26, 2018

By  Mikael Eriksson

Triathlon training and nutrition considerations for female athletes with Stacy Sims, PhD | EP#105

Stacy Sims, PhD, discusses female-specific considerations for training, nutrition, hydration and recovery. Women are not small men, so whether it's training or nutrition, you should be aware of these important differences compared to the male college students that are typically research subjects in endurance sports.

Discuss this episode!

  • Let's discuss this episode and the topic in general. Post any comments or questions in the comments at the bottom of the shownotes. Join the discussion here!

In this Episode you'll learn about:

  • Training, nutrition, hydration and recovery differences between men and women.
  • How to change your training and nutrition with your menstrual cycle. 
  • How too much fructose may be giving you gastrointestinal problems.
  • Training during and after pregnancy.
  • Training and nutrition changes for menopausal women. 

Sponsored by:

Precision Hydration

Precision Hydration
One size doesn't fit all when it comes to hydration. Take PH's free Triathlon Sweat Test to get personalised hydration advice tailored to what you're training for. Use the promo code THATTRIATHLONSHOW to get your first box of PH electrolyte product for free.

Triathlon Corner

Triathlon Corner
The new online home of shopping the best triathlon products in the world to great prices. Ships worldwide. Brands include Garmin, Stages Power, Café du cycliste, Zipp, Mako, Zone3, Hoka One One to name just a few. Use the discount code THATTRIATHLONSHOW to get 10% off.


About Stacy Sims

1:16 - 

Stacy's expertise

4:08 -

  • Almost everything out there that's on training and nutrition from a scientific perspective has been done on 18-22 year old male college students.
  • Women are leaving a lot on the table with regards to performance potential because they are training and recovering like men.
    • Women have a menstrual cycle and different hormones that perturb the way we respond to things.
    • Taking this into account can help women access their extra performance potential and is accompanied by improvements across the board.

The importance of the menstrual cycle

5:30 - 

  • The basis of it is to look at a woman's menstrual cycle and ways to train in and around it to maximise potential.
    • A typical cycle is 28 days - day 1 is the first day of bleeding, and this onset occurs because oestrogen and progesterone drop.
    • So the first two weeks of a woman's cycle (day 1-14) is where they can work to improve their strength, their overall top end power, their aerobic or anaerobic capacity.
    • When you reach the high hormone phase (day 20-28) oestrogen and progesterone are at their highest and it's hard to hit the top end in training.
      • You would use this as a maintenance or steady state phase.
    • You want to work with this cycle when planning training and recovery.
  • This can go across the board - from endurance work to strength work.
    • There have been some good studies coming out about strength training showing that women who do 5 days a week of strength training for the first 2 weeks, then back down to a maintenance phase in the last week before the bleeding starts gain more lean mass and lose more body fat than women who train 3 times a week every week.
  • It's important to understand that in the high hormone phase your core temperature is elevated, you lose more total body sodium, and you have a harder time recovering because progesterone is catabolic so it's harder to repair muscles.
    • You also have increased central nervous system fatigue - you've "lost your mojo" and can't hit that anaerobic capacity.
    • This makes you have a greater predisposition of putting yourself in an overtrained or overreached state, and getting immune compromisation.
  • Women have a reduction in their ability to absorb fructose compared to men.
    • Men can absorb 66g of fructose per 100g whereas women can only absorb 26g.
    • A typical sports product contains a mix of maltodextrin, glucose and fructose - women can't absorb maltodextrin or fructose as well as men - they sit in the gut.
  • Women are more predisposed to gastrointestinal distress because oestrogen causes more inflammation and leaky gut.
    • As oestrogen rises at ovulation and in the high hormone phase, there is a higher predisposition for leaky gut.
    • Introducing traditional sports drinks which have largely been tested on males can also cause severe gastrointestinal distress.
  • Many women email me asking if they should take immodium to avoid diarrhoea in their races.
    • I work with this by establishing what phase they're in, work with imflammation, reduce fructose and assess what they're ingesting.
  • In the first two weeks of the menstrual cycle women can conserve more carbohydrates, but as oestrogen rises it inhibits carbs coming from the muscle so facilitates free fatty acid use.
    • Although this can be good in some ways, it means you can't hit intensities or anything that you're used to and will need to take on increased carbohydrate during your workout in order to provide carbs for the working muscles.
    • E.g. If you have a high intensity workout that falls a few days before your period starts, add a little bit more carbohydrate to reach the intensity.
      • If you were to do the same workout a week later once the bleeding has started, your body wouldn't need the extra carbs.
  • Hydration is a contention in this area as there are different schematics to consider.
  • For example, women are more predisposed to hyponatremia than men.
    • This is not because they have slower times or larger body surface areas, it's because their body kicks out more total body sodium due to progesterone.
    • Due to this predisposition, women need to think about what they are eating and drinking more.
      • Drink something functional. A typical sports drink is too high in carbohydrate and doesn't have enough sodium and potassium.
      • It's not about electrolyte replacement, it is about fluid availability.
    • If women are eating and drinking things containing sodium, and drinking new generation drinks with lower carb, higher electrolyte content, it attenuates the hyponatremia risk.
  • When a man and a woman do the same race in similar times, when they finish the man's blood sodium level will be higher than the woman's.
    • Men tend to finish endurance events with hypernatremia (higher blood sodium levels) and women tend to be lower. This is a specific sex difference which is important to consider.
  • Your thirst sensation alters as you go longer and longer, and palletisation is another key sex difference.
    • In men, the salty and sugar sensation from a drink is not as strong as it is for women.
    • E.g. a women would try a Gatorade or a Powerade 2-3 hours into a race and not be able to drink it anymore, but a man would.
    • Women are able to drink less than they need too, and when they become super thirsty will just drink water, which also predisposes hyponatremia.
  • In the high hormone phase of the menstrual cycle, a woman's plasma volume (water part of her blood) drops by 8%.
    • If you race during this phase you are already starting compromised with a lower fluid availability for sweating so you must pay attention to what you're drinking.
  • However, I don't recommend planning races around your cycle because it becomes too difficult.
    • This information allows you to put specific interventions in place to avoid the negativity of the high hormone phases.
    • E.g. It would be the same as someone who has patella femoral syndrome who has a race. Leading up to it you'll do everything possible to avoid the pain and get to the race in the best condition.
      • You'll be taping, you'll be rehabbing, taking NSAIDs etc.
    • It's the same with the menstrual cycle, you're training around it and altering nutrition to enhance adaptations.
  • Most likely because of stress, your cycle is likely to change, and it may well happen that your period comes on race day.
    • In this situation, you can work on dampening the inflammation response these hormones cause in the 5-7 days prior to it starting.
    • You would want to be taking magnesium, zinc, omega-3 fatty acids.
    • You would increase the amount of carbs and sodium in your race and training nutrition.
    • You would increase protein intake after exercise to promote recovery.
    • These interventions all work to mitigate the supposed negative effects of the hormone changes.

Stacy's book 'ROAR'

18:23 - 

  • Roar came about in a conversation I was having with Selene Yeager (co-author) who had been involved in a few of the women's camps I was doing when working with Osmo Nutrition.
  • The book is a review of all the literature and disseminating it out.
  • It talks about:
    • Are you pregnant?
    • Are you menopausal?
    • Are you on an OCP (oral contraceptive pill)?
    • Are you having a regular cycle?
    • How to change your nutrition, change your training, adapt to the heat, how to use pee sticks to dial in your nutrition.
    • How to counter pre-menopausal syndrome and bloating.
    • What is your body type and how can you eat for that?
  • It goes into detail on everything I think women need to know, and probably don't know. Pick a chapter!

    Training and nutrition considerations during pregnancy

    20:25 - 

    • It's hard to get research ethics to study pregnant women so most of the research out there is either anecdotal, case studies, or observational control trials.
    • If you are fit and racing and become pregnant, keep going!
    • Calorie intake changes when pregnant, but not by much:
      • 150-200 calories extra a day for the first trimester.
      • 300 calories extra for the second trimester.
      • 400-500 calories extra for the third trimester.
    • It's important to eat good food and pay attention to B vitamins and other vitamins your doctor will inform you about.
    • When it comes to training, don't stop because you feel like you're going to impede or hurt the baby.
      • When you are exercising and you cut off a little bit of the blood flow to the uterus and the growing fetus, it's not harmful.
        • In fact, that response is going to increase capillarisation of the placenta so then the baby gets increased blood flow.
      • There's lots of research to show that if you are continuously doing exercise, you're downplaying the genetic predisposition for the baby to become obese, develop diabetes or cardiovascular disease.
    • Your body does not let you go anaerobic when you are pregnant.
    • I still have women whose doctors say they can't run in case it shakes the baby lose.
      • This won't happen! The baby is in the uterus and is wrapped in the amniotic sack which is a cushion for the baby.
    • Unless you have a medical condition that tells you you need to stop exercising, keep moving!
      • If you are fit and you become unfit it's very harmful to the baby.
      • If you are fit and you keep going, you're actually benefiting the baby.
    • There's so much people don't tell you after having a kid! You need to talk to someone who has had one, not just read the books.
    • When you first get out of hospital with the baby, you still look pregnant.
      • Everything is swollen, your uterus has to contract, your hip bones are wider and your pelvis has spread - everything is a little bit lax.
    • Think of it this way: for the first 6 weeks it's as if you have broken a bone. You're not going to run, you're just doing lots of easy stuff similar to active recovery from a race.
      • You are healing, so is your body, and you're trying to develop milk to breastfeed.
    • After 6 weeks, most physicians will give you the okay to exercise.
      • You will need to do a lot of pelvic floor work and ensure that your pelvic bones are realigned.
      • Many women have difficulty riding and running after having a child because the pelvic bones have widened and sometimes when they close there is pelvic torsion or other misalignment.
    • It's fine to train when you're breast feeding. Take in extra calories and pump before doing anything anaerobic.

    Training and nutrition considerations for menopause

    25:49 - 

    • The biggest thing that menopausal women need to think about is protein and power.
    • You start to lose muscle integrity, and the ability to have fast contractions.
    • You want to eat high quality protein, i.e. not soy, rice or pea protein as there is not enough leucine in there.
    • You want to do more power-based training, not long slow endurance training.
    • These changes can mitigate some of the abdominal adiposity that is so endemic in menopausal women.
      • Your body becomes more sensitive to carbohydrate and you need more protein.
    • The general recommendations that come from a physician's office often suggest soy protein, and to increase carbohydrate intake to help with hot flashes.
      • From a physiological standpoint, and research purpose, this is the exact opposite to what a menopausal woman should do.
    • You need to increase your good protein from whey, casein or fish. If you're vegan you can use a combination of pea and quinoa to increase the leucine content, or using vegan branch chain amino acids.
      • You're looking for 2g of protein/kg body weight.
        • This is the same recommended amount as for endurance athletes doing 2-3 hours on average of exercise a day!
    • You need to downplay carbohydrate except for in and around training.
      • This helps increase lean mass development, attenuate the body fat gain, and keep training hard.
    • To fit in the strength sessions, athletes will likely need to swap out some of the long, slow, endurance type sessions and put in short, sharp sessions.
      • These can be done in the gym, on the bike or running intervals.
      • If you give yourself 36 hours recovery you can still end up doing two days of work but with a longer recovery: do one session in the morning and the other on the second afternoon.
      • You're manipulating your training to give yourself a longer recovery without compromising your training week.

    Listener Question

    • ​Is there a difference in recovery needs between female and male athletes?
    • There's a specific recovery nutrition window that is commonly talked about: you need carbohydrates and protein within 30-45 minutes.
      • This is based on the recovery window of men. 
    • Women come down to complete baseline after 90 minutes, whereas men can have 3-18 hours depending on how intense the exercise was.
    • Women need to be aware that progesterone is catabolic, and you're never without it, so your first priority it to start muscle anabolism.
      • You want to kick start repairing the muscle and get the cortisol as low as possible.
    • Within the first 30 minutes you want 25-30g of really good, high quality protein, with 50-60g of carbohydrate to facilitate that protein uptake.
      • If you do this, it opens up your window for glycogen recovery to 2 hours, instead of 45 minutes.
    • For men, you can use a 4:1 or 3:1 carbohydrate to protein ratio and recover really well.

    Rapid fire questions

    31:48 - 

    • What is your favourite book, blog or resource
      • I don't have one! I'm so wrapped up with research I don't have time to do anything else.
      • I'm enjoying reading about experimental myth and methodology at the moment. 
    • What is your favourite piece of gear or equipment?
      • A bike trailer because my kid can ride her bike with me. 
    • Who is somebody in endurance sports of nutrition research that you admire and look up to?
      • Nina Stachenfeld from the John B Pierce laboratory at Yale. She has been doing a lot of research in the past 20-25 years on progesterone and oestrogen and how it affects fluid balance in woman and men. 
      • She's spot on with her research, very humble but also very direct and smart. 

    Key takeaway

    • Plan your training according to your menstrual cycle can be important.
      • In the high hormone phase (days 21-28) it's not ideal to do intensity, so take that as a scheduled easy week/recovery week.
    • If you still need an intense workout in this phase, you may need to take on more carbs during exercise.
      • Your body can't access it's carb stores in the same way as normal so you need exogenous carbs to go at a higher intensity.
    • Fluid availability is also different between men and women and you need to plan your hydration strategy properly.
    • Post workout nutrition is different for men and women! Women need more protein compared to men, and the ratio of carbs to protein is lower on the carb side than men.
      • E.g. men need 4:1 carbs to protein, but for women the ratio is about 2:1.

    Links, resources & contact

    Links and resources mentioned

    Connect with ​​Dean Golich

    Connect with host Mikael Eriksson


    Hi! I'm your host Mikael,

    I am a full-time triathlon coach and an ambitious age-group triathlete. My goal is podium at the Finnish national championships within the next few years.

    I first started the website Scientific Triathlon in autumn 2015 as a passion project to share my learnings with a larger triathlon audience. Later on, in early 2017 I started the podcast That Triathlon Show. 

    I sincerely want you to contact me to

    • Send me feedback
    • Give constructive critic​ism 
    • Request topics and guests for the podcast
    • Send me your triathlon-related questions 
    • Tell me that you've rated and reviewed That Triathlon Show so I can give you a shout-out on the show and tell you how much it means to me!
    Subscribe to That Triathlon Show and never miss an episode!


    Let's discuss this episode and the topic in general. Post any comments or questions in the comments below. I'll be here to reply and take an active part in the conversation, so don't be shy! 

    Mikael Eriksson

    I am a full-time triathlon coach, founder of Scientific Triathlon, and host of the top-rated podcast That Triathlon Show. I am from Finland but live in Lisbon, Portugal.

    Please contact me if you have feedback on the podcast or want to make suggestions for improvement or send in a question for a Q&A episode.

    If you are a long-time listener and appreciate the value the podcast brings, please consider taking a couple of minutes for leaving a rating and review on iTunes/Apple Podcasts, or wherever else you can think of leaving a rating and review.

  • Hi,
    I loved listening to this episode on women specific nutrition, hydration, and training. I am just now getting into a more intense schedule of training for a sprint triathlon. I’m racing local races and hoping to do well at those. I would like to know how having an IUD effects your cycle hormones and how that relates to how hard you should go during specific times in your cycle. More specifically, since getting an IUD I get very sporadic periods. Sometimes going as long as 3 months without one. Does this change my hormone levels? Does not having a period change the intensity levels of the workout I should/can do? What specific things mentioned in this podcast apply to me?

    • Hi Hab,

      Thank you so much, really glad that you enjoyed the episode! I don’t know the answer to your question myself, although some googling did result in me finding this article saying that “Most women using Skyla (>95%) have their usual changes in estrogen and progesterone each cycle, and most release an egg each month. Many women using the Mirena (75-85%) are having their usual hormonal cycles after a year and still releasing an egg”, when talking about hormonal IUD:s.

      So in these cases at least, I would assume the same things apply as talked about in the episode.

      But that said, since you don’t have a period I can’t give a specific answer. I’ll try to email Stacy and ask her if she has time to respond to give you a better answer.


      • Hi all-
        Yes, with the IUD you will still have perturbations in estrogen and progesterone, the way the IUD works is to change the mucus so that the sperm isn’t motile to the egg, and/or prevent ovulation. You may feel episodes of premenstrual syndrome on an IUD because you still have hormone flux, and if you are on a progestin-based IUD (eg Mirena) you may find recovery needs include more protein.

  • I really enjoyed this episode, it answered a lot of questions I didn’t even know I had. I am curious you mention a ‘Good Quality Protein’ also Zinc and magnesium. This is something we hear quiet often ‘Good Quality’ but what does that mean? I know to stay away from labels that promise magical fixes but what is it exactly we should be looking for that qualifies a protein powder or supplement to be ‘good quality’

    • Hi Jess!

      The most important factors to consider for what is a “quality protein” is 1) the amino acid profile (ie. what essential amino acids does the protein contain) and the rate of absorption.

      After exercise, you want a quick-absorbing protein, and as complete an amino acid profile as possible. In particular, leucine is a very important essential amino acid for muscle protein synthesis.

      For the above reasons, I’d recommend whey protein isolate, especially post-workout. It’s fast absorbing and high in leucine.

      In heavy training periods to supplement with some extra protein, a casein protein as a night-time, slow-absorbing protein is a good one too.

      Vegans need to find some plant-based protein that’s as high in leucine as possible, but none of them contain as much leucine as some of the non-vegan proteins like whey and egg, and they also tend to be slower absorbing.

      Also, when discussing powders, note that an isolate (like whey protein isolate) is more concentrated in protein (it doesn’t contain carbs and fats, or only minimal amounts) than a concentrate.

      Here’s some more information:

  • This is great information, however when you’re not having a cycle every 28 days, how can you possibly track your nutrition/hydration?? I just ran the Boston marathon and saw the inside of 4 porto’s ?

  • {"email":"Email address invalid","url":"Website address invalid","required":"Required field missing"}

    Explore our products and services