Recently, my husband said he had a surprise for me.  My mind was spinning with all the possibilities and you guessed it….It was a couple’s Lactic Threshold test!  A two-for-one. So sporty, so romantic. 

So last Sunday morning, there I was preparing for my first LT test, with a borrowed heart rate monitor, and wondering what waters I was about to dive into. Why would I, a 40+ mom with two young kids, need to know about my lactic acid limitations? Well, I was about to find out.

The backstory.
My husband got more into running last winter while living and working in Baja, Mexico, as a great early morning exercise option to stay fit and sane while beating the heat. Recently, he put his training to the test at the Steamboat ½ Marathon. He had dabbled in heart rate training and calculated his pace hoping to come in at 1:40, roughly 7.6-minute miles. Well, he miscalculated and “blew up” on the last mile and came in at 1:48. For shame. (FYI This would beat my best time by 10 minutes, but who’s counting.)

Ultimately his curiosity was peeked. He wanted to know more about his lactic threshold heart rate, or LTHR–the point at which enough anaerobic metabolism occurs for more lactic acid to be produced than can be rapidly cleared from the body. Crossing this threshold will make your endurance performance rapidly decrease. In a race, one might maintain a higher level of lactic acid for up to an hour, but at a certain point, you will slow down. So he called up a local friend, D.O. and exercise science guru Dr. Jon Freckleton for a consultation, and I got to go along for the ride.

As mountain bikers, primarily, we hit up our local pride and joy, Emerald Mountain, for the on-trail test venue. Jon brought all his booty to test our blood on the trail and instructed us to repeatedly climb the same four-minute hill at a various paces that yielded more intense heart rates. At the top of each interval, he pricked our fingers and tested our lactic acid levels. We learned that both of our LTHRs were in the mid-150s. I was thinking, okay great, what do I do with that information? I don’t even own a heart rate monitor for Pete’s sake.

Well, it turns out if you “train” with a little intention you can A) get faster on your bike (that’d be nice), B) burn fat more easily (I certainly need that after 3 months in Mexico) and C) learn a little more about yourself, and D) have something else to focus on this summer besides client work, kids’ camp schedules and earlier than normal Outdoor Retailer media appointments. I’m in! Bring it on!

Dr. Jon proceeded to provide us with a litany of workouts to do in a given week. (It sounds like a lot of riding in a week, but it should provide more bang for your buck with less time invested.) To increase fitness, speed up and to spark my middle-aged metabolism, Jon recommended 1 long, slow day with the heart rate under 140 and 1 race pace day (for me, this will be an average ride with my fast girlfriends who kick my ass on the regular). Additionally, he suggests 3 interval workouts per week, which include: four 4-minute intervals at a HR at 155 with full rest in between; two 10-20 min. intervals at a 152 ceiling with full recovery or two or three 20 min. intervals with 5-10 min. recovery; and one day with 6 or more “Tabatas” which is maybe Latin for going full out for 30 seconds, 30 seconds off. (Just kidding, it was invented by Dr. Izumi Tabata, a Japanese physician and researcher.) Your heart rate goes through the roof at 165-170 plus and you may feel like puking around #4. All the rest of your miles are at a heart rate of 140 or lower, although this is harder to accomplish on a mountain bike than one would think and even harder if you are used to riding in a fast-paced group.

So what does it mean for a middle-aged mom?

Well, this middle-aged mom is game to try. A friend and I were recently talking about middle age. How it’s a point of decision. Do we wither away or fight against it, and possibly, just maybe, get better and faster with age? I’ll take an attempt at the latter and see what happens.  My new Garmin fenix 5S is ordered and on the way. Until then, I’ll be out on my bike suffering and clinking a glass after, saying “Tabatas for ALL!” Even middle-aged moms.

By: Erin Brosterhous