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May 2020

Running Economy

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The concept of running economy (RE) – the amount of oxygen our body uses at a given speed and distance – is akin to fuel efficiency in a car.  If we have a heavy car, with a big engine, going up a hill or pressing the pedal hard as the light turns green, our fuel economy suffers.  So it goes with running.  Ideally we’ve got a trim chassis, run with an even pace, lean easily into the hills and then motor down them.

Most books on running devote space to this topic.  Pete Magill, Jordan Metzl, Owen Anderson, and Tim Noakes come at it from a slightly difference angle.  However, for the endurance runner it boils down to what percentage of the oxygen we have at our disposal is being used to move us forward at a submaximal pace.  Other than a finishing kick this is the pace we run.  While VO2max gets a lot of attention, RE is crucial.  Many highly successful runners have respectable but not top-end levels of VO2max.  Frank Shorter, for example, had a 72% VO2max but regularly beat competitors with 80%+ levels.  RE is closely related to the concept of fatigue resistance, which Anderson defines as “the ability to sustain a high-quality velocity for an extended time without a falloff in pace or intensity.”  We’ve all encountered runners who seem to glide along while we are pushing our limits (of course they may be doing a good job of hiding their discomfort!)

Training improves both RE and fatigue resistance.  Mileage, speed, hills, strength work, stretching and good form support both measures.  To be sure, there is also a genetic element involved, though genes seem less important with RE than VO2max, for which improvement is fairly limited.   Running form bears close attention, as inefficient biomechanics leads to wasted energy.  A commonly cited example is heel striking.  Ideally, when our foot contacts the ground it is near or under our center of gravity enroute to toe-off and forward movement.  However, when first contact is with the heel, there is momentary braking, seen with a slow-motion view of one’s gait.  It’s something like continually tapping the brake pedal when driving.  We may not feel a jerking, but we’ll certainly notice the effect on our gas mileage (and ultimately in our brake pads!)

At first blush, it seems RE should decrease with age.  Everything else does!  But the research does not support this.  Yes, older runners slow down, but it’s due to a decline in the various components of RE that drive this. Confusing, perhaps. Recall that RE is an efficiency measure, not the measure itself.  If one person drives a Prius and at best gets 55 mpg and another drives a Honda Civic, topping out at 40 mpg, the Honda driver getting 38 mpg (a 95% efficiency) has a higher RE than the Prius driver getting 50 mpg (91% efficiency).  A 2011 study led by Tim Quinn from UNH compared RE in runners under age 40, 40-59, and 60+ at four speeds for five minutes between 10:00 and 6:40 min/mile pace, which for all the runners was a submaximal pace.  They showed similar RE for all three groups.  Not surprising, the % of maximal VO2max attained was highest in the oldest group.  Meaning to run 6:40 pace, the oldest group had to use more of their capacity.   Measurements showed the older runners had decreased flexibility, muscle strength, maximal heart rate, and VO2max compared to younger runners.  No wonder they had to work harder!

Of course this is hardly new news.  We know our top-end VO2max is in the rear view mirror.  And we already know we have to work harder than the 30-something next to us to drive the pace in a race.  Thus, it comes back to doing all we can to get as close to 100% of our reduced potential as possible, with smart training (including long runs, hills, intervals, and striders) and proper rest and training periodization.  These are things under our control.

Bottom line, we put a lot of time into our training and want to be at our very best on race day.  Let’s make sure we prepare well, fill our tank with good fuel and not be tapping the brake.  And thoroughly enjoy it, even if it feels harder, to go slower! 

The Eyes Have It

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Taking a break from Covid-related news, I came across a 2018 article in the ACSM Health and Fitness Journal extolling our marvelous (and maybe underappreciated) eyes.  Certainly those with impaired vision do not take their eyes for granted.  My father in his 80’s suffered a mini-stroke and woke up effectively blind.  He lived another 10 years but his enthusiasm for life waned as he was a voracious reader.  Many others have had sight complications earlier in life or even at birth.  But for most of us, we rely on our eyes without thinking a whole lot about them.

So, James Peterson’s article “Ten Nice-to-Know Facts About the Eyes” caught my eye, literally, and I thought my blog readers might find this interesting.  So a bit rephrased, here are his 10:

  1. Our eyes are nearly full size at birth.  The rest of the body grows around them!  For those with normal vision about 80% of what we learn and remember is due to sight.  
  2. After the brain, eyes are the most complex and powerful organ in our bodies.  With them we distinguish shapes, colors, depth, and adapt to changes in light.  The tiny muscles controlling the eyes don’t get time off — they are on 24/7.
  3. The eyes feed images to our brain for translation, allowing us to see.  If anything disrupts that transmission, all is blank.
  4. We blink about 5 million times a year, helping to lubricate the eyes and remove debris.
  5. The eye is composed of over 2 million working parts (rods, cones, muscles) and over 100 million cells.  A stack of 100 million dollar bills would be 7 miles high!  These types of numbers are hard to fathom.
  6. Eye color is determined by the amount of melanin (a natural pigment) in the front layer of the eye.  Melanin has protective properties.
  7. Eye health is affected by our diet.  Fruits and dark leafy greens are particularly good for eyes.
  8. Our eyes have 256 unique characteristics, whereas fingerprints have 40.  Meaning, eyes will probably become increasingly used identifiers.
  9. Regular eye exams will alert us to glaucoma, macular degeneration, and cataracts, conditions typical in older adults and which early detection may allow for treatment.
  10. Eye transplants are not in the offing.  Connecting 100 million nerve fibers is beyond the current or foreseen abilities of medical technology.  If we’re fortunate, we get one good set of eyes to use and care for.

So, on your next run, perhaps you’ll find yourself thinking about the many virtues of our eyes while navigating the trail, watching flowers, birds, and the bikers, walkers, and other runners coming along (with or without masks).  And then go home and enjoy a kale salad!

Silver Linings

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Each week, the faculty and students in my program at UVM hold a seminar, often to review a current paper in the medical literature.  The program is in the College of Medicine, so topics often center around clinical trials.  Not exactly running related, but it’s a great group of smart people and I’ve learned a lot about the research process, which can apply to running as well.

Last week, we discussed an article in the New York Times examining whether the number of deaths from Covid-19 are being accurately reported.  Probably not, and several reasons were given.  First, there is often a delay in reporting, sometimes up to several weeks.  But that sorts itself out eventually.  A second bigger issue is how the death certificate is read. There are usually four lines on a death cert, with the top line considered the primary cause.  Presumably this is the line used for reporting the Covid deaths we see in the news.  However, with older people having several health issues, Covid-19 may have merely been the final straw.  The attending physician has to make a determination about the primary cause, and likely there are inconsistencies around the country.  Also, there may not have been testing for Covid-19 post-mortem, thus it doesn’t show up anywhere on the death cert.  A third issue are deaths of those with other life-ending conditions who missed out on care at the hospital or PCP’s office due to lack of access. There’s no way to count that but it’s out there.  

Regardless of whether the official or “real” count is 90,000, 150,000, or more, a looming concern is the fallout from all of this, something akin to PTSD, leaving some in a state of fear and suspicion. This may limit what people will do, how much they travel, etc.  Others will find themselves in a financial hole that may take years to recover from.  Optimism can turn to pessimism and then depression.  (As if there is not already enough to be depressed about on the current national and world scene!)      

With that as ominous background, I wanted to convey what was offered as we went around the room (via Zoom of course!) to hear what people saw as lessons learned and potential upside from navigating the pandemic, i.e., silver linings.  Here’s what I was able to jot down, in no particular order:

  1. “I will never take my friends for granted again.  And will treasure the time we can spend together, in person.”
  2. Greater appreciation for health care workers.  They have been pushed to the front lines and are vital in the effort to control the virus, but have always been there for us.
  3. Greater appreciation for service workers of all stripes: grocery store stockers and clerks, pharmacists and techs, gas station attendants, postal workers, FedEx/UPS drivers, taxi and Uber operators, food preparers and deliverers, trash haulers, etc.  Collectively these people enable us to pick and choose when and where we go.
  4. Realization we don’t need as much stuff as we have.  It’s eye-opening how little we actually need.
  5. The use of telehealth has moved forward exponentially (meaning insurance now covers it).  Prior to Covid-19 it was at a standstill.
  6. Carbon emissions are way down and that is already affecting the atmosphere.  It shows how quickly the natural world responds. We CAN retool our carbon footprint, if we put our minds to it.
  7. Education can be delivered in novel ways using the most current technology.  In Vermont, that has also highlighted the need for broadband in rural areas.
  8. Working some from home may have benefits, such as more time with the family.
  9. Greater understanding that we live in an interdependent world.  Unfortunately, it seems an opportunity is being lost for the U.S. to show global leadership.
  10. In Vermont, perhaps as well as anywhere, teamwork in state leadership is evident.  Political squabbles have been put on hold and everyone has grabbed an oar and is pulling hard.
  11. We’ve discovered things walking and biking around our neighborhood that we never knew were there.  It’s actually a pretty special place!

We’ve got a ways to go to get out of the woods.  And we know it won’t happen all at once.  School is out for the year but plans for in-person classes at UVM next fall are taking shape.   Businesses are opening up in stages.  The expectation is outdoor recreation options (golf, tennis, etc.) will open up in the next couple weeks.  Perhaps with restrictions indoor fitness facilities during the next month.  That will be welcomed — I see and feel my muscle tone evaporating!  Eventually, road races with some new guidelines will return, maybe by August or September.  

This is certainly a time in our lives we won’t forget.  Much like 9-11.  Though not sure there is much upside to gather from that.  But from Covid-19, there is upside to consider and that is probably worth keeping in our sights.