“I don’t know about you, but I have had my share of ‘bonking‘ episodes during endurance events.  Bonking refers to the depletion of glycogen or basically the condition in which your muscles run out of fuel.  This year I decided to get a handle on this by going from bonking to glucose monitoring.  I started my transition by working with a nutrition coach to refine my diet.  (For more info on Sheree’s journey with her nutrition coach, click here.)  For 6 months I increased my protein & fat intake & reduced my sugar intake.  The idea is that, by changing macronutrients, the body will begin to burn fat more efficiently.

Using a Glucose Monitor:

Recently I tested my results by wearing a glucose monitor.  Every 5 minutes the monitor would send a reading of my blood sugar level to my phone.  The readout would show me if the levels were too high, too low, or in the safe zone.  As predicted, my new eating habits resulted in more stable blood sugar levels.  Yay for that!

I experimented with the monitor during a long endurance event to see if my blood sugar could stay level over hours of exercise.  I planned to wear the monitor on a 100-mile bike ride which I estimated would take me 7 hours to complete.

For this event, I felt I had a solid eating plan – I ate my regular breakfast consisting of 2 eggs, spinach, Greek yogurt, nuts, seeds & some berries.  This is now my ‘everyday breakfast’ as it doesn’t spike my blood sugar.  I also felt had a solid fueling plan – I planned on skipping all the high sugar treats at all the rest stops.  I brought my own almond butter to put on bananas & I had nuts & dates to fill in the gaps.  Wow – was I prepared?!  Surely nothing would spike my blood sugar & I should be able to burn fat all day.  Right?!!

I arrived at the event start with plenty of time to find a good parking spot, check my tire pressure & load up my bike.  I wasn’t stressed at all.  In fact, this wasn’t even ‘a race’.  Just a nice charity ride with my friend on a beautiful June day in Utah.

What?  My Blood Sugar Levels Are Off?!

What happened next really surprised me.  There we were at the start & I received an alert from my phone – ‘YOUR BLOOD SUGAR IS DANGEROUSLY LOW.  TAKE IMMEDIATE ACTION.’  How could this be?  We hadn’t even start riding yet.  I thought there must be some mistake.  After a careful inspection of my monitor, I saw that I had a high blood sugar spike while we were getting to the race & getting our bikes ready (see blue arrow on graph below).  Somehow just the logistics of parking & getting to the start caused an adrenaline spike in my blood sugar!

When blood sugar spikes there is a corresponding release of insulin.  This release of insulin caused my blood sugar to then plummet below normal levels (see red circle on graph below).  That’s right…below normal levels right at the start of a 100-mile bike ride.  Yikes!

My Take-Away:

My big Take-Away is that just getting to the start of an athletic event can drastically impact my blood sugar levels.  I mean, if my adrenaline spikes this much prior to an event I’m not even worried about, what will happen in October when I show up to do the triathlon I really care about?!  I know I will have a lot on my mind, not to mention actual nerves.

The point is that we need to be aware of the demands that the mental & emotional aspects of our sport(s) have on our bodies.  And then we need to be proactive in addressing those demands.  I’m not sure I have a solution yet…but I’m going to try some calming mental exercises & a banana prior to the start.  Who knows!  This just might be the key!”

Editor’s Note:

While anyone can train their metabolism to become more fat-dependent, it is a process that takes time & training.  Case in point:  Sheree had been adjusting her macronutrients (more protein & fat, less carbs) for 6 months prior to attempting an endurance event without eating carbs at the aid stations.  From my own experience, I would agree that it takes about 6-9 months of daily nutrition adjustment before your body is ready to rely on fats during exercise.  Go slow & give your body time to adjust.  If you’re interested in my daily nutrition plan, I did “A Week in My Life” series.  Click here to start w/ Monday.