Interesting study on impact of Mediterranean diet on metabolic diseases and CVD

Another interesting study published last week, comparing the impact of the "traditional anti-CVD diet" with the Mediterranean diet.

The study by Institut d'Investigacions Biomèdiques in Spain observed a number of adult individuals with high risk of CVD (cardiovascular disease). The individuals suffered from a range of metabolic disorders, including obesity, high blood pressure, high triglycerides, high plasma glucose etc - all associated with increased risk of death from CVD.

Some were put on the "recommended" diet for people with CVD: essentially low fat, with an overall calorie restriction. The others were put on a Mediterranean diet, which consisted of fruits, vegetables, lean proteins, and fats (olive oil, nuts and seeds), with no calorie restriction (i.e. eating to satiety). The Mediterranean diet consisted of around 50% total fat intake (as percentage of total kcal consumed).

The subjects were observed over a period of 1 year and their metabolic health was assessed throughout and at the conclusion of the study.

The results were not surprising to me but perhaps to many of those educated in 1980s-1990s medicine: the high fat no calorie restriction Mediterranean diet resulted in far better improvements in metabolic health and reduced risks for CVD when compared to the low fat calorie-restricted diet.

The study was not perfect:
- While the Med Diet group didn't gain weight, they didn't lose much (my guess that this was due to lack of physical activity and abundance of grains and legumes in the diet)

- The scientists hypothesized that the subjects on the Med diet were experiencing improved fat oxidation (they became better at burning fat) - however this was not tested for saturated fats, only mono and poly unsaturated fats from olive and oil and nuts/seeds.

In any case, the evidence remains compelling that a higher fat diet resulted in lower CVD risks when compared to a diet designed to lower CVD risks...

I'm copy/pasting below the conclusion from the study, followed by a link to the full literature.

"Since the primary endpoint for the treatment of MetS is to reduce the risk of CVD, traditional dietary recommendations such as those proposed by the NCEP, AHA and NHLBI essentially involve following a low-fat diet and achieving weigh reduction by a combination of reduced caloric intake and increased physical activity. In our study, however, we found that a high-fat (>40% of energy) non-energy-restricted diet showed a reduction in MetS prevalence without the need for weight loss or prescribed physical activity. There are several important aspects to consider regarding the MD followed in this study. First of all, it is highly palatable, decreases hunger, and promotes satiety, hence improving long-term adherence compared to low-fat energy-restricted diets [31]
[31]. Therefore, the results of this study suggest that there is no rationale for maintaining the fear that a MD rich in fats of vegetable origin may cause weight gain, and that it may be a useful alternative to traditional low-fat diets for the dietary treatment of MetS."

http://www.plosone.org/article/info%253Adoi%252F10.1371%252Fjournal.pone.0085202 

Fasted Race Experiment Successful... no shovel required!

Glad to report that I'm ok. Racing Abu Dhabi Short in a fasted state did not result in me collapsed by the side of the road begging passers by for an energy gel or Coke...

Some background
Yesterday I took part in the Abu Dhabi International Triathlon (ADIT), racing the Short distance - except there is nothing "short" about it: 1.5km swim, followed by 100km bike, followed by a 10km run.

Hello Abu Dhabi!

I take part in this race every year: being a Dubaiyite (as my wife calls us Dubai residents), it's considered our "local" race, I also often use this race to experiment with something new. Last year, I used the race to experiment with new nutrition products from Hammer Nutrition. While the products worked great, I misjudged my hydration, became dehydrated and had a miserable race full of cramps (which you can read about here).

This year, however, I went in the complete opposite direction: I wanted to race the event on nothing but water. That's right: no energy gels, no energy bars, no electrolyte tablets, no coke, no gatorade... just good old fashioned water, for a race that typically takes between 4 and 5 hours and coincides with the beginning of the UAE summer heat.

But I'm not an idiot: I didn't just wake up last week and decide to race "on an empty stomach". During the past 2 months or so, I've amended my diet and training to become more fat adapted. In other words, I've been teaching my body to prioritize the use of fat as a primary source of fuel both for exercise as well as for daily living. At the end of this blogpost, I'm outlining some of the main things I've adopted to become more fat adapted.

The purpose of my plan to race ADIT "unfueled" was to determine whether I was fat adapted enough to tap into my fat resources to fuel me through the entire race, without the need to resort to energy gels/bars/sports drinks.

Why am I doing all this? What's the harm in consuming carbohydrate-rich energy gels and drinks? Primarily for health reasons: I have diabetes in my family history, in addition to heart disease, high blood pressure and triglycerides, all linked to high carbohydrate consumption. I talked extensively about all this here.

I also did not make use of any electrolyte supplements (e.g. Saltstick, Nuun, Gu Brew...). These are claimed to replenish electrolytes lost in heavy sweating. All the research I've read in recent months about the topic point to the fact that it's virtually impossible to deplete yourself from electrolytes to the point of causing cramps in a single day event, unless you've had 0 salt/mineral intake with your food in the days leading up to the event (another impossibility).

So water was all there was (with some amino acids, as I explain below).

The X Factor
While my aim was to isolate the "fat adaptation" aspect in my experiment to make it the only "factor" in the race, there was a somewhat significant "X factor": my race fitness, or lack of it to be exact. I honestly haven't trained much in recent months due to a combination of personal and work-related matters. I had enough fitness to carry me through the race, but not enough fitness to "race" the race.

I knew I would have to look at my post-race results with that lens...

Preview and Race Conditions
The race took place on Saturday March 15th. I drove up on Friday morning, checked into the hotel, registered, did the pre-race usual (dropped off bike in transition, etc.). On Friday, conditions were horrible: heavy rain, heat/humidity, and gale force winds to boot. We were all hoping that things would calm down overnight...

and calm down they did...

On Saturday, we woke up to clear skies and no winds. The rain had left something behind though: we were looking at 80% humidity throughout the day, and the air felt thick. We also knew that the winds would pick up over the course of the day, as they always do in this part of the region.

The Race Plan
Nutrition
Breakfast - 2 hours before race-start: Bulletproof Coffee +3g Amino Acids
Bike: water +1g Amino Acids on the hour every hour (so 3g)
Run: water

Some explanations:

Bulletproof Coffee? What the heck is that?: Click here for an explanation. Why? Well the fat content in the Bulletproof Coffee actually triggers the fat burning metabolism (called beta-oxidation) in your body. In other words, it "starts the fat burning engine", thereby allowing you to tap into your fat reserves.

Why Amino Acids? Amino Acids are the basic building blocks of proteins. I take a small amount (6g in total) just to protect my muscles from destroying themselves too much during long endurance events, like a triathlon. I don't get energy from Amino Acids, they're more preventative than anything else (again following the theme of minimize the negative health implications of endurance racing).

Race Execution Plan
In order for me to get through the race without resorting to energy gels/bars/drinks, I would have to stay in my "fat burning" zone of effort. This typically means an effort of around 75% of my maximum effort on the swim, the bike and the run.

Why? Well your body uses 2 sources of fuel primarily: carbohydrates and fats. Fats provide more energy, but they take longer to burn. Carbs produce less energy, but they are "quick".

• So if your effort level is "hard" (e.g. 80% or more), you need energy "quickly", so you will need carbohydrates. You have some stored in your liver and muscles, enough for around 90min of effort. After that, you'll need to eat carbs to replenish and keep going (gels, bars, sports drinks, etc.)

• If you keep your effort level around the 75% mark, you can use "fat" as a source of fuel. You have hours and hours worth of fat stores in your body (no matter how lean you are). 

Of course, you can't just wake up and assume that your body will chose fat. Our typical diet has unfortunately conditioned our bodies to operate on carbs, even at low levels of effort. 

What I've been doing over the last 8 weeks or so is "recondition" my body to learn to burn fat for anything other than a "hard" effort (I describe some of what I did at the bottom of this blogpost).

Swim:
I opted for no wetsuit, even though it was going to mean a slower swim. My lack of swim training meant that going 45sec faster with a wetsuit would not have made any difference. In addition, the air was warm and thick with humidity, conditions I normally struggle with anyway, so I didn't want to risk overheating during the swim by wearing a wetsuit.

Target effort level: 75%, comfortable pace

Bike: 
Plan was to bike also at a 75% effort, making use of my Vector power meter and heart rate monitor to gauge my effort and keep it steady throughout the bike course (i.e. avoid spikes which would push me into carb-burning zones, which are typically above 80% effort).

Run:
Same as bike: keep it at 75% effort and use heart rate monitor to maintain a stable pace.

Race Day
Preparation
I woke up at 5am after a good night's sleep. It's funny, I don't get nervous much before races, a big step from a couple of years back when I would spend the night tossing and turning.

I ordered fresh coffee from room service, and while waiting for it, spent 5min doing some breathing exercises. Those have a dual purpose of (i) oxygenating my blood/muscles and (ii) warming up my breathing muscles (diaphragm, rib cage muscles).

When the coffee came, I prepared my bulletproof coffee, and while sipping it, I completed a quick warmup: pushups, burpees, lunges. Nothing crazy: just getting the blood flowing to all muscle groups.

I got my kit ready, took 3g amino acids, and headed downstairs to catch the shuttle bus to the race venue.

I got to the race venue and it was buzzing with activity. The Pros were about to start, music was blaring, and there was this infectious energy in the whole place, which I love and missed since my last big race at Challenge Roth in July.

A bit of a burst bubble happened when I realized that my bike computer (Garmin Edge) was stolen off my bike overnight! I couldn't comprehend it: the only people with access to the bikes were race officials and other athletes. What kind of athlete steals a bike computer!?

Anyway, I had my old trusty Garmin Forerunner 310XT in my bag, and I had charged it overnight as a backup. I put it on my wrist, paired it with my power meter and heart rate strap, and headed down to the beach to warm up before race start.

The Swim (1.5km)
I was in a wave of around 300 other athletes. I started on the side (no point in getting bashed around too much). When the horn went off, I plunged it and tried to settle into a rhythm immediately. I had to deal with kicks and blows for the first 5min or so (typical of a race start), but then things cleared up and I was swimming super comfortably.

Results: at this stage, I experienced the impact of the Bulletproof Coffee for the first time: I had never experienced such mental clarity during the beginning of a race. I was acutely aware of where I was in the water, I was reacting a lot quicker to other swimmers, and I was very much focused on my streamlining, body position and stroke. Certainly the most comfortable swim in any race I've taken part in.

I came out of the water in 32:10. Slow, but expected.

Thanks Christian for the pic!

Transition 1
T1 in ADIT is a bit of a long one. You run up the beach, through a fresh water shower, into a changing tent to grab your "bike bag" and change, then out into the large area where all the bikes are.

Again, I was super comfortable as I was running into the tent. My "bike bag" was empty, because all what I needed (helmet, race belt, sunglasses) were hanging on the hook where I left them. I grabbed them and put them on as I was running towards my bike.

Grabbed the bike and ran with it to the mounting line. I had left my bike shoes clipped into the pedals, so I ran across the mounting line, hopped on, slipped my feet into the shoes and started pedaling away.

T1: 4.5min. Rusty, lack of practice shows.

Bike (100km)

2nd bubble burst: as I explained earlier, my plan was to use my power meter and heart rate monitor to make sure I stayed in my "fat burning zone" of 75% effort. Of course, that requires being able to see the power you're producing or your heart rate. 

Since my bike computer was MIA, I had put on my backup Forerunner on my wrist. But when I looked at it on the bike, it was "dead': water had gotten into it during the swim (no idea why) and it just refused to restart.

Switching to Plan C then!

I had 2 choices at that point:

1. Throw the experiment out the window, smash the bike segment, grabbing energy gels from the aid stations throughout; or
2. Try to estimate what 75% feels like using my breathing and "perceived exertion" and stick to the experiment.

I opted for option 2.
How I executed it was pretty simple: 75% effort means I should be able to breath through my nose. Every time I had to breath through my mouth, I would slow my effort down until I regained control of my breathing. Of course I "let that go" on the bridges somewhat, but just by 10% or so.

The bike ride was otherwise super-smooth. I stayed on the aerobars for pretty much the entire ride (except for tight corners on Yas Marina GP Circuit).

I was grabbing water from every aid station (and nothing else). It was getting hot and very humid very quickly, so I was drinking around 800ml/hour (estimated, I had no watch/bike computer/Garmin!!).

Results

Positives: never ever felt any energy dips or lack of power. Never felt the need to take any energy gels/bars/drinks. Felt super steady and consistent in my effort, and it was very easy to regain control of my breathing after going up bridges and flyovers.

Negatives: none really. The only thing I struggled with was the fact that I was getting passed by so many people in the first 40km or so of the bike. 

This is something I'm not used to: the bike normally being my "strength", it's usually the other way around for me. 

I took a little pleasure in the last 40km though: I was passing a lot of the people who had passed me earlier, even though I was still putting out a 75% effort. Many people were beginning to fade as the winds picked up during the second half of the bike.

Total time for 100km: 3:12 (avg 31.2km/h)

Transition 2
T2 was uneventful. Got off the bike just before the dismount line, leaving the shoes clipped into the pedals. Dropped off my bike at the first empty spot I could find and jogged to the transition tent feeling very comfortable. Helmet off, shoes on, visor on, and off I went for the 10km run.

Saw Christian Berglehner from Race-Me and my club-mate at TriDubai on the way to the changing tent, and he snapped a pic:

Run (10km)
The moment I stepped out of the tent, I realized how hot and humid it was. It was close to mid-day and the sun was blasting, and I already knew that the run course had no shaded areas whatsoever.

Again, I had no heart rate monitor, so I had to gauge my effort by feel to keep it at 75%. 

I already knew what that meant for me (that's how I train myself and others): 75% means I'm able to keep a 4/3 breathing pattern. 3/2 means I'm beginning to go above 80%, and that was a no no for this particular experiment.

Remember what I mentioned earlier: 80%+ effort means you're dipping into stored carbs, and you only have 90min of those in your body. I was already 4 hours into the race, and I certainly did use some of those 90min during the swim (aggressive start) and the bike (bridges and flyovers).

Now the major parameter that influences how fast you go at a particular level of effort is your fitness. For example, someone who can run at 11km/h at 75% effort is fitter than someone who can run at 10km/h at 75% effort.

Things are also negatively affected by heat and humidity: if you normally run at 10km/h at 75%, the heat/humidity will drive your effort to 80% for the same speed of 10km/h. Some people (e.g moi) are more susceptible to hot weather conditions than others.

Results

I started the run feeling ok, and kept my pace very slow to control my breathing and maintain that 4/3 breathing pattern. 2km into the run and I started to lose control: I couldn't maintain a 4/3 breathing pattern anymore, which meant that my effort level was creeping above 80%. I had to slow it down since I still had 8km to go. 

But I know myself. This has nothing to do with how "fat adapted" I am. This has to do with how "unfit" I am. Given the lack of training over the past few months, I just was not "capable of staying at 75% at 6min/km", and the only way I could was by slowing down to a walk.

I started a new pattern:

• Run at 75% until I couldn't
• Walk until my breathing recovered
• Restart running at 75%

That went on until the 9km mark, when I decided that I still had some of that stored carbs left: I picked up the pace and ran the rest of the way to the finish at 85-90% effort.

A highlight of the run was seeing TriDubai trisuit after TriDubai trisuit. Such a big presence for our club at such a major race made me immensely proud! Shoutouts from Venny, Johan, Patrice, and countless others were uplifting!
Run time: 1:17 (slow as a snail).

TOTAL TIME: 5:11 (263rd out of 381 in my age group).
I crossed the finish line a little out of breath, but I can honestly say that I finished "fresh". I wasn't tired, no muscle pains, no cramps whatsoever…

But the most important thing of all: as with the swim, my mind was "clear". I had never experienced this mental clarity at the end of a brutal 5hr race. No mental fog, no dizziness, no blurred vision, etc…

Carbs are famous for causing mental fog in the best of conditions, but I always thought that the mental fog at the end of a long-distance triathlon came from the exertion… not this time!

I was chatting to some of the guys at the finish, and I could recall every minute of my race and could tell them what was happening at every one of those minutes. It was an incredible feeling…

Conclusions and Next Steps
In my opinion, the experiment was a resounding success: I never felt out of energy and my level of energy was steady and consistent throughout the whole event.

This is all hypothetical of course, but allow me to run some numbers:

The following were my swim/bike/run paces at 75% a year ago (when I was far more race-ready):

• Swim 1.5km: 29min (vs 32min today)
• Bike 100km: 33km/h (vs 31.5km/h today)
• Run 10km: 55min (vs. 75min today with walks)

In other words, I'm convinced that this experiment was successful enough to warrant a second attempt after a few months of training.

I'm registered for Norway 70.3 In July. Will I adopt the same there? Probably not. Not because I will stop fat adapting (I won't) but because I don't want to "race" Norway 70.3 at 75% effort. It's my "A" race this season and I'm looking at going hard (85% effort).

Having said that, I will certainly continued to teach my body to tap into its fat resources, because that will make me more efficient at ALL effort levels. 

This will certainly reduce the amount of carbs I will need to ingest during the race in Norway, which ultimately would be beneficial for my health.

I'm competitive, and all for getting a good result in my races, but not at the expense of increasing my risk of diabetes 10 years down the road…


How did I "fat adapt" over the past few months
I'll start off by admitting that I stuck to this plan around 70% of the time, and "fell off the wagon" around 30% (partially on purpose, partially due to either travel, entertaining, or lack of will power).

On the training side, it was pretty simple:

• Unlike what some traditional people recommend, I did not only train at 75% or lower efforts
• I trained like I normally would: a mix of longer endurance sessions (75% effort) and higher intensity efforts (80%-95%)
• My longer sessions lasted from 60-90min on the runs and 90-180min on the bike
• All of my longer endurance sessions were done in a fasted state (water only)
• All of my higher intensity sessions were under 60min and were pre-fueled

On the nutrition side, I adopted a high fat, high leafy greens, moderate protein, low carb approach.

• Fats accounted for around 55% of my diet.
• Proteins accounted for around 20%
• Carbs accounted for around 25%.

You will note that I still had carbs. Carbs at 25% means I was adopting a "low carb" diet and not a "ketogenic diet". I won't get into the details on the differences, but suffice it to say that keeping carbs at 25% consistently is a lot easier than you think.

• Fats included: grass-fed butter, coconut oil, olive oil, avocados, raw nuts, sardines, salmon, eggs, bacon
• Veggies included: spinach, rocca, tomatoes, olives, bell peppers, 
• Proteins included: grass-fed beef, lamb, free-range chicken, duck, fish & seafood
• Carbs included: quinoa (also source of protein), potatoes, fruits, rice (rarely).

Note: when I started this fat adaptation around 8 weeks ago, I could barely run for 60min on an empty stomach and without fueling. By last week (pre-race), I could run for almost 2 hours in a fasted state first thing in the morning feeling absolutely fantastic. It works people!


Finally, I have to say that my whole fat adaptation process resulted in a number of positive consequences which were not the reason I embarked on this in the first place:

• My body composition improved dramatically, despite my limited training: I dropped 2.5% of body fat in 6 weeks
• My GI problems all but disappeared (carbs have been proven to be a major cause of GI problems since the "bad bacteria" in your gut only feed on carbs).

And here is a list of "experts" whose knowledge and experience I draw upon a lot in my education about how our bodies work, how best to fuel, and whose experiences and knowledge I've drawn upon for this whole experiment:

Ben Greenfield

Dave Asprey

Mark Sissons

Chris Kresser

Tony

Interesting study on fat metabolism

Most of you have heard me talk over and over about the frustrating but highly rewarding (and certainly healthier overall) fat adaptation process, which teaches your body to prioritize stored fat as the primary fuel of choice for daily living and physical activity.

Doing fasted cardio exercises to “burn” fat, as many advocate, is certainly not enough: fat burning stops the moment you hit that big red STOP button on the treadmill. It takes much more to transition your body from a “carb-burning engine” to a “fat-burning engine”.

I’m only saying this to provide context to an interesting study just released (you can read the full study here):

Here is a summary along with my observations:

The Study 

Comparison of “Fat Oxidation” at rest and during exercise between young “Sedentary Lean (SL)” and “Sedentary Obese (SO)” individuals.

Fat Oxidation means the body’s ability to “burn fat” for energy. I found it interesting that both groups in this study (Obese and Lean) were both “young and sedentary” – this means that any differences in Fat Oxidation between SO and SL are likely to be even more pronounced if SO were to be compared to physically active individuals.

Another interesting element is that both groups (SO and SL) were young, generally healthy, and with the same fasting blood glucose level (i.e. even the Obese group did not have high fasting blood sugar). So essentially, you are comparing obese vs. lean among generally healthy, young, and sedentary people.

The Findings & Discussion

Findings regarding Insulin levels (all measured at rest):

• SO group showed Insulin levels 3 times higher than the SL group. This means that while the SO individuals are not diabetic, their pancreas is working 3x harder even when fasting – this is alarming as an overworked pancreas is a primary cause of diabetes

• SO group showed Insulin Resistance to be almost 4 times higher than SL group! This means that even though the SO group is producing 3x more insulin, their liver and muscles (which are supposed to respond to insulin by removing glucose from the blood) are becoming less sensitive to all that insulin circulating in the blood – basically, they’re ignoring that message being sent from the pancreas telling them to remove glucose.

This is indeed alarming, because a combination of high insulin levels and high insulin resistance presents the absolute ideal circumstances for diabetes to develop.

Findings regarding physical ability:

• Max Power output on a stationary bike: the SO group produced 21.5% less power on the bike vs. the SL group. Again this is interesting because both groups are young, generally healthy, and sedentary. So the SL group did not produce more power because they’re physically fit or active, but only because they are “leaner”.

• HRmax for SO: 168bpm, while HRmax for SL: 183bpm. This is the max heart rate scored during exercise on the stationary bike (i.e. how high you can get your heart rate before you have to stop). Once again, a big difference was recorded between the 2 groups, even though the SL group was just as untrained and sedentary at the SO group.

I suppose I should not be surprised by this, but it is an interesting observation nonetheless: obese sedentary individuals suffer from impaired strength (power on bike) and cardiovascular ability (heart rate) when compared to their sedentary leaner individuals. I would have expected this in a weight-bearing exercise (such as running or cycling outdoors), but I did not expect this to be so clear-cut on a stationary bike.

Findings related to fat burning efficiency:

The findings here were the most interesting from my perspective:

• Sedentary Obese individuals were found to burn more fat at rest and lower intensity exercise compared to the SL group. This reversed at higher intensities: the SL group was able to maintain fat burning at higher intensities, while the SO group’s ability to burn fat fell off. No, this is not a license to sit around watching TV, because…

• …the more interesting observation was that while the SO group burned more fat at rest and low intensity exercise, their bodies’ efficiency at burning fat was actually lower than that of SL.

In other words, the only reason the SO group showed more fat burning at rest and low intensity exercise is because they have more of it to burn, but they are far less efficient at doing so.

In other words, the SL group is a fuel-efficient car with a 30L tank burning 0.5L/km, while the SO group is a pre-diabetic car with a 60L tank but burning 1.5L/Km.

Tony

Menstrual Cycle Impact on Training and Performance

I know I'll be getting a lot of grief from male athletes for this one. After all, as if we're not getting chicked often enough in races!...

Don't shoot the messenger!!

Highlights

- How your menstrual cycle impacts your training and performance
- How to time your races against your menstrual cycle for peak performance
- How training can impact the frequency and duration of your cycle
- How severe calorie deficiency can lead to stress fractures
- How contraception pills can help you train better and strengthen your bones
- My recommendations on how to train to be ready to race at all times

Biology 101

As most of you already know, there are 2 "primary" hormones that differentiate men from women: Estrogen and Progesterone.

Estrogen

What many people don't know, is that Estrogen, in addition to controlling the development of sexual characteristics and development related to pregnancy, also plays important roles in bone protection, blood coagulation, menstrual cycle functioning, cholesterol production, and salt and water retention. 

In fact, the concentration of circulating Estrogen in the blood is the single most important determinant of bone mineral density in women.

Estrogen deficiency caused by Amenorrhea (missed period as a negative consequence of large training volume) is the most significant risk factor for osteoporosis (bone fragility) and stress fractures among active women). 

ATHLETE IMPLICATIONS: Estrogen also influences pulmonary function, body temperature, fat metabolism and blood plasma volume (therefore fluid retention and hydration), all critical aspects for endurance sports.

We're going to delve into the impact of Estrogen on training and performance later...

Progesterone

Progesterone is one of the primary hormones involved in preparing the female body for the conception of a newborn. It has multiple functions both in terms of preparing vital organs for the fertilization of the egg as well as gestation.

However, in addition to these important functions, Progesterone has been shown to be involved in a number of other physiological functions. 

Progesterone:

- Acts as anti-inflammatory and helps with immune response
- Regulates gall bladder activity
- Normalizes blood clotting, circulating zinc and copper levels, cell oxygen levels
- Increases the usage of fatty acids (fat) as a source of energy, raises glycogen stores and reduces lactate - all have obvious implications for athletes which I discuss further below
- Plays an important role in the signaling of insulin release and pancreatic function, thereby impact risk of developing diabetes

Your Menstrual Cycle and how it affects your training and performance

Let's start with the basics:

The menstrual cycle is typically 28 days long and is divided in half by ovulation on day 14:

- The first half of the cycle is called the Follicular Phase

- The second half is called the Luteal Phase.

ATHLETE IMPLICATIONS: Each of these phases has hormonal and physiological characteristics which have a significant impact on your training and performance, as I explain further down.

The Follicular Phase starts with menses (period) - following menses, Estrogen rises, peaking around day 14, right before ovulation. A burst of Estrogen at the end of the phase causes a surge in luteinizing hormone to initiate ovulation. Progesterone stays low

The Luteal Phase starts at ovulation - Progesterone rises, Estrogen drops and rises again towards the middle. The increase in Progesterone causes an increase in body temperature (to prepare for egg fertilization). If fertilization does not occur, both Estrogen and Progesterone drop quickly, triggering the onset of menses.

Source: www.sciencebasedmedicine.org/

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A note on bloating and PMS:

Why do you sometimes feel bloated during your cycle: high concentration of Progesterone during the Luteal Phase (phase 2) affects fluid balance, causing you to lose water and electrolytes. The rapid drop in Progesterone at the end of the phase (if egg is not fertilized) results in excess premenstrual water and electrolyte retention, creating that bloated feeling.

What causes PMS and what can you do about it: PMS is a series of uncomfortable symptoms triggered by the rapid drop of both Estrogen and Progesterone at the end of the Luteal Phase when the egg is not fertilized. 

The cramping during PMS is thought to be caused by the hormone prostaglandin, which is produced by the uterus and causes it to contract (the cramping). Birth control pills and anti-inflammatory drugs (such as Ibuprofen) can reduce cramps by inhibiting prostaglandin. 

A note on Ibuprofen and other over the counter anti-inflammatories: as I mentioned earlier, these drugs inhibit prostaglandin. But you have to be aware that prostaglandin plays a big part in the health of your gut lining, and inhibiting prostaglandin puts people at risk of deterioration in gut health and creates the potential for gut leakage (and it doesn't take long for that to happen).

Only limited research has been conducted on the effects of exercise on PMS (assign blame as you wish) - but whatever research was done did yield significant results supporting the theory that exercise does reduce PMS symptoms (results varied among individuals).

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So the impact on performance then?!

Well as I alluded to earlier, the Estrogen/Progesterone cycle influences:

1- Basal Body Temperature

2- Metabolism (utilization of fat vs. glycogen as fuel)

1- Impact on body temperature and its effects on training and performance

The chart below illustrates the change in your "Basal Body Temp" during the cycle. Basically, your Basal Body Temp is the temperature your brain considers to be "normal" and does not trigger either sweating to bring it down or shivering (for e.g.) to raise it.

As you can see from the chart, your Basal Body Temp rises gradually during days 14 to 24 (Luteal Phase), with a sharp "spike" around day 25.

Remember the hormonal chart above? This coincides with the gradual rise followed by a "spike" in Progesterone during that same period of time.

In effect, what is happening is that Progesterone is triggering an increase in your Basal Body Temp in preparation for the possible fertilization of an egg.

So on days 6-14 for example, a body temp below 36.2C is considered "normal", while on days 20-28, a body temp of 36.6C or higher is considered "normal". The difference may only be 0.4C, but that has big implications!

ATHLETE IMPLICATIONS:

The Hypothalamus in your brain acts as your "thermostat", regulating body temperature. When it detects a sudden rise in body temperature above your Basal Body Temp, it triggers sweating to cool you down and bring the body temp back to Basal.

What causes this to get triggered? It could be ambient temperature (walking in hot weather), exercise (active muscles producing heat as a bi-product), etc.

Now your muscles need that stable body temperature to continue functioning. I won't get into the chemistry of why that happens, but many have experienced how heat impacts ability to exercise. 

AND, your muscles don't really care that your Basal Body Temp is being adjusted upwards in preparation for the fertilization of an egg. They want the temperature to be "stable goddammit !!! What's all that about letting it rise to 36.6C or 37C ??!".

But here's the problem:

Days 1-14: Basal Body Temp is low - if body temp goes above it, that triggers sweating and cools it back down. Muscles are happy.

Days 14 onwards: Basal Body Temp is now high - sweating doesn't happen until body temp rises above the new, "now higher", Basal Body Temp. Muscles are NOT happy!

And muscles not happy = feeling horrible during training and lower performances = heat exhaustion...

And it's not just muscles: when exercising in heat, increased thermal strain comes with greater cardiorespiratory strain:

1. Sweating causes loss in blood plasma volume

2. Which causes a lower stroke volume (how much blood the heart pumps with each "beat")

3. Which leads to less oxygen to muscles

4. Which means that the heart has to beat faster to compensate

==> this is what we call cardiac drift: your HR rises by 3 to 5 bpm for every 1% body weight lost from dehydration

Of course, this can be averted with proper hydration - and now you can see why I'm always banging the table about hydration :-)

And who's the culprit behind all this: well it's Progesterone, because it is the one telling the Hypothalamus: "hey buddy, I'm preparing for egg fertilization, so don't you dare trigger sweating until the body temp reaches this new higher number!"

And here's another interesting piece of info: both Estrogen and Progesterone affect women's breathing during exercise. In fact, Progesterone has been shown to increase breathing and severity of asthma symptoms as well as the "Rate of Pereceived Exertion" or RPE (how much effort you "feel" you're putting out).

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A couple of side notes on this whole Basal Body Temp thing:

Head Adaptation: by training sporadically in moderate heat, your body becomes more efficient at sweating. In other words, it teaches your body to start sweating earlier at ALL body temperatures. This is one way to deal with this issue if you must train or race during those peak Basal Body Temp days.

Oh and by the way, as some of you may know, the reason your doctor has you monitor your body temp if you're trying to get pregnant is exactly because of this whole mechanism: a rapidly rising Basal Body Temp means that Progesterone is rising and ovulation is about to happen - perfect timing to conceive a future athlete!

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2- Impact on metabolism

Let's start with some general information which I'm sure female readers will love and male readers will hate.

Ok let me put it out there once and for all: women are better equipped for endurance racing than men "metabolically". Again, don't beat me up for it boys! Women have a better fat metabolism period.

In fact, if you were to look at average finishing times in running races between men and women, you will see the difference shrinking as the distance increases.

As a matter of fact, in 2002 and 2003, Pam Reed won the 217km Badwater ultramarathon, posting the fastest time overall, beating all the men.

If you would like to know more about this inspiring athlete, read her book: The Extra Mile.

You want further proof? Here are the differences between men and women for the world record over increasing distances:

- 5,000m: 11.0%
- 10,000m: 10.8% 
- Marathon: 8.5%
- 100km: 5.5%

Spot the trend there?

Studies have shown that women rely more on fat as fuel then men. A number of studies have shown that female athletes on average use 75% more fat than male athletes at efforts between 65% and 70% of VO2max (aerobic efforts).

Additional training further increases the number of mitochondria (cellular power plants) in muscles, thereby assisting in fat utilization (in both men and women). This type of training has to be specific to fat adaptation tough.

Of course, there's a catch: as you burn more fat, you burn less glycogen (the carbohydrate stores in your liver and muscles). And that's a good thing! Because while women are better at burning fat than men, they have lower glycogen stores to begin with.

Again, diet and training influences how much glycogen you can store, but still, no amount of training and diet can bring women's carb-storing capacity in line with men's.

So forget carbo-loading at races ladies! It doesn't do much! But still come along, we enjoy your company ;-)

In fact, relying heavily on carbs in your diet will teach your body to burn more carbs, but since you have a lower ability to store carbs in the first place, you could be leaving your naturally given fat-burning potential on the table!

And because of the higher fat utilization / lower glycogen utilization in women, the rate of muscle breakdown is lower, and you can recover quicker from workouts... (fantastic, just what we male athletes needed)

So what does all this have to do with the Menstrual Cycle?

Estrogen is partly responsible for higher fat utilization as fuel in women - when male rats are given Estrogen, they utilize less glycogen and have higher circulating fatty acids (indicating an increase reliance on fat as fuel). In fact, those same studies have shown that injecting these male rats with Estrogen increased their endurance.

Lance probably knows better, but wouldn't Estrogen be cheaper than EPO?

So this means that any heavy-training-induced drop in Estrogen level will affect your fat metabolism.

But it's not that clear-cut I'm afraid: Female athletes have shown an even higher level of fat utilization and lower lactate during the Luteal Phase, when Progesterone is high. 

So it seems that while Estrogen does provide women with a better fat metabolism then men, Progesterone is what maximizes that ability.

ATHLETE IMPLICATIONS:

That creates a bit of a dilemma right? We have 2 conflicting pieces of information now:

- Race during the Follicular Phase (phase 1) because low Progesterone keeps your Basal Body Temp low, ideal for your muscles to function well

- Fat metabolism peaks during the Luteal Phase (phase 2) when Progesterone is high.

What to do then?

While no significant studies have been conducted to explore these 2 conflicting phenomena, observations have shown that the best performances were reported during the early days of the Follicular Phase, and the worst during the Luteal Phase. 

In other words, expect to perform well when Estrogen is dominant and worse when Progesterone is dominant.

It seems that your body's temperature is more critical to your performance in endurance races than the "marginal" increase in fat utilization induced by Progesterone.

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So my personal take on how to structure training would be as follows:

- Improve your overall fat-adaptation so you can burn more fat in both phases

- Make sure you add some heat acclimatization into your training to "teach your body to start sweating earlier at all Basal Body Temps"

- Make sure you include higher-intensity training to develop glycogen storage capacity

==> This should equip you optimize your body to deal with any condition:

- If race falls during the Follicular Phase (phase 1): your Basal Body Temp is low (optimal), your fat metabolism has been increased through training, and while you do use a little glycogen, you have more of it since you trained to increase its storage capacity.

- If your race falls during the Luteal Phase (phase 2): your heat adaptation allows you to start sweating earlier despite the higher Basal Body Temp, the high Progesterone levels will make you more fat-efficient anyway, and you can tap into those glycogen stores to put the hammer down in the last few Kms!

General Note: in my opinion, specificity in training is key not just to get fitter and faster but also to stay healthy, injury-free, save time and avoid burnout. 

A training program with good specificity will capture the adaptations needed to work "around" your menstrual cycle and enable good performance throughout the month.

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How does heavy training affect the cycle and what can you do to fix it?

What does heavy training do to the cycle and your overall well-being

As we discussed at the beginning, low levels of Estrogen caused by excessive training without adequate caloric intake significantly increase risks to bone density.

Bone Mineral Density peaks for both sexes around age 30, but the "female peak" is lower than the "male peak". This means that female athletes need to be a lot more careful with how much pressure they put on their bones (e.g. increases in run volume). 

This becomes even more critical if irregularities in the menstrual cycle are observed (risk of low Estrogen), and this why your doctor would be asking you to take Vitamin D and Calcium supplements (importance of Vitamin D in bone health was discussed in a previous blog here).

Furthermore, heavy training shortens the Luteal Phase (phase 2), followed by cycles without ovulation and finally cessation of menses (amenorrhea), related to constantly low levels of Estrogen and Progesterone, where levels of Estrogen would be similar to post-menopausal women.

And once again, Estrogen is that gives women the metabolic "edge" through higher fat utilization. Lower Estrogen starts to give that advantage away. Combine that with lower glycogen storage capacity, and you can guess the impact on training and racing.

So what can you do?

Research has shown that this hormonal imbalance is not because of the stress of exercise but rather because of severe caloric deficit. 
Some studies have shown that women who exercise heavily but fuel well (pre, during, post) prevent amenorrhea.

One way to help increase bone density in active women with menstrual irregularities: oral contraceptives, which increase Estrogen and regulate the cycle.

However be careful, different pills have different concentrations of Estrogen / Progesterone, and some of them "cycle" the ratio 2-3 times during each menstrual cycle.

One additional word of caution: check iron levels if heavy bleeding occurs regularly during menses.

A special thanks to Dr. Jason Karp whose book Running for Women was an important source of information for this article.

Happy training!

T