Not Just a Man's World

Last week I spent some time writing about what the contraceptive pill and other hormone-based contraceptives do to our hormone cycles, when compared to the natural cycle that our bodies would follow without contraceptives.

This week I’m going to pull together some conclusions about what that might mean for our diet and training.  Hold onto your hats for a rollercoaster article, ladies!

Some brief revision of the hormone cycle and the hormones

I’m not going to go into too much detail repeating previous material so a quick read of my posts about the menstrual cycle hormones and what the hormones do may help.  However, I’m going to kick off with a quick refresher of the main characteristics of the female sex hormones.

Progesterone

• Promotes protein catabolism (you can get more energy from protein than usual)
• Inhibits uptake of glycogen to the muscles
• Research suggests that performance in endurance sports is best when the oestrogen:progesterone ratio is high, though this seems to potentially be irrespective of which of them is elevated.

Oestrogen

• Promotes glucose availability and uptake into the muscles.
• Improves ability to burn fat for fuel.
• Suppresses protein catabolism.
• Oestrogen deficiency can cause impaired regional blood flow when exercising, but I wonder if this is actually oestrogen deficiency in relation to progesterone?

Hormone-based contraceptives

• Results in elevated progesterone hormone for three weeks in every four.
• Potentially high progesterone to oestrogen ratio for those three weeks.
• The fourth week (when no contraceptive pill is taken) the body undergoes hormone withdrawal – I’m unclear exactly what happens but the implication is that both hormone levels drop off – most noticeably progesterone which has been unusually high.

Fitting this into our contraceptive-skewed menstrual cycle

To say that I have been dismayed by the conclusions I reached would be an understatement.  My conclusions suggest that even our contraceptives are perpetuating the myth that women are only good at endurance work.  Although this may also be an explanation for why it is that so many women seem to excel at endurance activities. 

For this analysis I’m working off a typical 3-weeks-on-1-week-off cycle that you would see with the combination pill.  For those with a longer-term hormone intake, you probably want to take my conclusions for weeks 1-3 and extend them to “all the time”.

Weeks 1-3 (while taking the contraceptives)

• Elevated progesterone: oestrogen ratio means that endurance sport performance should be excellent.
• Protein catabolism should be excellent due to the high levels of progesterone.  This could well explain why I can subsist quite happily on a diet with macronutrient ratios of 70:5:25 (P:C:F) when Chris would just fall over trying to base so much of his diet on protein.
• Uptake of glycogen to the muscles is inhibited.  This is bad on two scores:  first, any carbs you take in won’t be processed effectively and are quite likely to end up in fat reserves unless your muscles are crying out for glycogen (eg. you just finished a really heavy resistance session and the muscles are really badly depleted); and second, recovery post-workout may be less good if you’ve done a resistance training session since your body may not be effectively replenishing glycogen stores.

I’m assuming that the oestrogen included in the combination pill ensures that those of us taking it don’t suffer from the poor regional blood flow which is characteristic of oestrogen deficiency.  However this may be something to consider when taking a contraceptive which is solely progesterone-based, such as the progesterone-only contraceptive pill.  Poor regional blood flow could impair recovery during and post workout. 

Of course it could be that the poor regional blood flow comes from particularly elevated progesterone over oestrogen, rather than simple oestrogen deficiency.  If that is the case then it could explain why women perform better on full body workouts.  No single body part is taxed for too long, so that there is a reduced need for instant recovery (from the blood flow) and instead plenty of time for recovery (until the next workout when you use that muscle group again).

Week 4 (withdrawal week)

• Protein catabolism drops off a little so that high protein diet may need tweaking for the week to keep you feel satiated.
• Endurance performance might drop off as progesterone levels decrease, so this may not be the week to run a marathon and aim for a personal best time.
• Glycogen uptake to the muscles will improve, so you’ll probably find yourself more able to handle carbohydrates without it going straight to your waistline.  That is provided you are being active.  Warning though that this is a few more, not carte blanche to stuff yourself with cake, and if you are sitting at your desk all day you’re not really depleting your glycogen stores so this point is null and void.  They need some depletion to have space for the glycogen you then ingest (via the carbs).  This benefit may also make this a better week for resistance training, especially higher rep bodybuilding-style work where you want to exhaust the muscles and then ingest higher carbs to spike insulin and build muscle size.
• If we assume that oestrogen slowly starts to rise during this week off (with the body coping with withdrawal by starting a normal menstrual cycle again) then the body might be better at burning fat for fuel in this week so some extra fat in the diet (to replace some of the protein) might work well.
• The body is going through withdrawal.  As such it is likely to be under stress, especially at the very start of the week when the withdrawal first hits.  This is followed immediately by a bleed which is another stressor.  Overall we’re looking at a spike in stress hormones which could cause a period of muscular weakness and tiredness.  On top of that, Berardi has referred to a paper which highlighted the inverse relationship between cortisol and testosterone, so in the early part of the withdrawal bleed testosterone levels are probably low and really heavy lifting is likely to be tough.

In summary

For weeks 1-3, when taking the contraceptives, it looks like a diet with a high protein percentage should work well.  Keeping carbohydrates really low except for immediately post workout when glycogen stores are depleted and signalling in the body for replenishing those stores is high.  The body is also likely to cope really well with endurance sports and in the weights room total body workouts could well be the best bet.

Hitting week 4, when undergoing hormone withdrawal, the body can probably handle carbohydrates and fat better so consider replacing some of the protein with fat and allow a little more flexibility with carbohydrates as long as there is plenty of activity going on to keep depleting glycogen stores.  Endurance performance may drop off a little and heavy low rep resistance training should probably be avoided in the first few days (or at least taken carefully to avoid injury).  However, resistance performance may improve in the second half of the week and this could be a good week to do some bodybuilder-style hypertrophy work.

***** 

Unfortunately I’ve run out of space this week to look at the last part of this story.  Look out next week for a final part where I see how my conclusions stack up against information which some of my readers gave me a few months ago.  In the meantime, let me know what you think of these conclusions.

Related posts:

1. Menstrual cycle on the contraceptive pill
2. Blog-watch: impact of the contraceptive pill on performance
3. Blog-watch: interaction of diet and exercise with the menstrual cycle – part two
4. Blog-watch: interaction of diet and exercise with the menstrual cycle – part one