No ladies - I am not talking about going for a bike ride with your
BFF. I’m talking about your other ‘friend’ - you know the one that visits
you once a month. You know….
The Painters and Decorators are in.
Aunt Flo is visiting
Clean Up at Aisle One.
Come on - it could be worse. I
could be making puns about PERIODization Training..
But from a training and racing
perspective does it make any difference ?
Here’s why it does.
Your typical cycle is 28 days long and so your
first day of menses would be considered day 1. You typically complete that by
about day 5-7 and then the mucosal lining of your uterus begins to rebuild and
proliferate in preparation for the potential of an egg implantation. From day 1
all the way up to ovulation, which is usually about day 14-15, is called your
follicular phase and then you move in to what’s called the luteal phase
You’ve got your follicular phase; you’ve
got your luteal phase. During these phases you have different levels of
hormones based off the need or the lack thereof to repair the endometrial
lining in the uterus. As a lot of women know, there are different symptoms
that can accompany this cycles and some women don’t get any of those symptoms,
some women get lots of these, some women get some pretty significant
discomfort. From a training and racing perspective however it’s just not
changes in your mood or the way that you feel. There are also some pretty
significant changes in exercise performance and also the way that you respond
to fats and proteins and carbohydrates based off of where you’re at in your
menstrual cycle.
In simple terms we’ve got our low
hormone phase, which occurs early in the cycle, and a high hormone phase, which
occurs later on. In the High hormone phase women produce a lot of estrogen and
estrogen will decrease how much you rely on your liver’s storage carbohydrate, your muscle storage carbohydrate and increase your use of fat. This
means that when you’re producing a lot of estrogen, you have a bigger capacity
for burning fat and for sparing muscle and liver carbohydrate or
what’s called your storage glycogen. When you want to go up to a very high
intensity during exercise such as for HIIT sets, swim sprints, TABATA etc., when
you’re in that high hormone phase you might need a little bit more carbohydrate. During the low hormone phase, when you are producing less estrogen, you can
ingest less carbohydrate because you’re going to tap into your liver and into
your muscle carbohydrate a little bit more efficiently.
During the high hormone phase (day 14 -
28) you may need more carbohydrate in order to support HARD interval sets.
It is also why you might feel flatter
doing exactly the same set later in the cycle (high hormone) than earlier (low
hormone) as you are less efficient at tapping into the 'fast' energy source - glycogen.
The other really interesting thing that
happens is that during that high estrogen phase you’re using more fatty acids.
This means you return to your pre-exercise metabolic rate much more quickly with
the impact on training being that your post exercise feeding window when
insulin sensitive is high is much shorter. You should prioritise your
post workout meal to get it in right after you finish your workout when you’re
in that latter phase of your cycle if you want to optimize restoration of
things like your storage glycogen or restoration of amino acids. Whereas
men might be able to wait a good 2 or 3 hours because their metabolic rate is
still elevated and they’re still able to restore a lot of those metabolites,
Women, especially during their latter phase when in their high hormone phase, have a much smaller window and should aim to refuel as soon as possible
after the session.
Whilst I’ve spoken about Estrogen and its impact on
glycogen usage there are actually other hormones that cycle through the time
frame. During the high hormone phase you not only have high amounts of estrogen
but you have a high amount of progesterone as well. Progesterone increases how
much protein is used during exercise which means if you’re going to use amino
acids you'll most sensitive to them during the High Hormone phase.
What does this mean?
During days 1-14 (Low Hormone Phase) you might do
better with higher intensity or harder workouts as you are better able to tap
into storage glycogen, less reliant upon amino acids and less efficient at
burning fat as a fuel. Once you shift into days 14-28 you might do better
during longer workouts where you’re actually got more estrogen to be
able to tap into fat more efficiently, you’ve got more progesterone and you’re able
to utilize amino acids more efficiently and that might be a better time to do your longer slower workouts.
Hydration is also important here. When you
have elevated level of progesterone you’re baseline body temperature is
increased significantly and when your baseline body temperature goes up not
only you’re going to sweat more but you’re also going to need more fluid
typically to maintain body temperature. Now when you get high estrogen AND high
progesterone you get a reduction in your plasma volume and that’s why you get a
lot of swelling a lot of times during the latter phases of your cycle. A lot of
the volume from blood plasma goes between cells instead and causes bloating that
you typically experience. Because of this blood volume drop, you might need a
little bit more water and a little bit more electrolytes when you are in that
phase of elevated progesterone and elevated oestrogen (High Hormone phase)
Due to this reduction in blood volume during the
High Hormone phase you might find that you tolerate hot exercise a little bit less
and when you go for a run or a ride you need a little bit of extra fuel, you
might do better with a little bit more electrolyte intake like salting a little
bit more of your food during that part of your cycle.
Finally, when you’re producing more progesterone
and more estrogen, you are also going to get increased production of specific
hormone called relaxin and relaxin is something that pregnant women are gonna
produce in high amounts but also that you’re gonna produce towards the latter
phase of your cycle in higher amounts and this is responsible for softening and
relaxation of ligaments especially the pubic symphysis (hips). When you have a high amount of relaxin circulating in
your bloodstream, it can do things like weaken your spine a little bit so
you’re unable to withstand impact and twisting forces quite as much. You might
get increase propensity for knee injuries or hip injuries or ankle injuries so
once again during the high hormone phase you MAY want to drop the weight
slightly or, more importantly, be super careful with technique knowing that
your body is a bit ‘looser’ and less able to protect itself.
In summary
Days 1-14. Better suited to high intensity
exercises, weights
Days 14-28. Better suited to longer sessions
but be conscious of lower blood volume (heat sensitivity) and shorter refueling
window.