Thursday, June 22, 2017

Running and Your Heart, Part III: Coronary Artery Disease

Coronary arteries, as seen via cardiac catheterization.
photo: pinterest.com
Before we get into it, let's just reiterate that this post (or anything else you read on the blog) is NOT to be construed as medical advice.  This is for informational and general-knowledge purposes only.  Furthermore, while I have a pretty good grasp on this stuff, I'm NOT a cardiologist, and anything you might read here is subject to my own interpretations (or mis-interpretations).  As such, this blog should not be taken as a substitute for medical care by a qualified professional.  I'm happy to provide information and try to answer people's questions.  But I AM NOT YOUR DOCTOR.

That being said...this blog is getting awful science-y.

In my continuing effort to either confuse the shit out of you, or freak you out (no, no, JK), I thought we'd delve a bit more into the relationship between distance running and heart health/disease by focusing on the coronary arteries.  Last time I talked about the normal adaptations the heart makes to endurance exercise ("the athlete's heart") and how these adaptations can be both beneficial and, in some cases, harmful.  In that post we quickly glossed over the coronary arteries, but today we're going to examine that aspect of the cardiovascular system in greater detail, because it's extremely important and because a lot of recent research has examined this relationship closely.


photo: pinterest.com
Recall from last time that the arteries carry oxygen-rich blood from the heart to the various muscles, tissues, and organs of the body, supplying them with the oxygen necessary to perform their particular functions.  The coronary arteries run directly over the heart muscle itself, bringing oxygen to the heart tissue and allowing the heart muscle to fulfill its ceaseless task of pumping blood throughout the body.  Given the heart's position of primacy in the body, you can see how the entire system relies to large extent on the uninterrupted flow of blood to its muscle.

As discussed previously, the term "heart disease" can encompass a wide variety of problems with the various physiologic systems at play in the heart: anatomic, structural, electrical, etc.  But most commonly, when someone refers to "heart disease," they mean an abnormality within the coronary arteries that compromises the flow of blood and the delivery of oxygen to the heart muscle.  This can take the form of stenosis, a hardening and narrowing of the artery that can disrupt blood flow.  Such narrowing occurs when various junk, usually cholesterol, builds up within the lumen of the artery.  (Picture a pipe or a hose that gets clogged with dirt and how that affects the flow of water through it.)  Over time, these plaques can harden and calcify, causing the artery to narrow and stiffen.  These stiff, narrow arteries thus lose their ability to dilate (expand) in response to an increased demand for oxygen--for example, during exercise.  So when a heart with narrow, inelastic coronary arteries is placed under the stress of exertion, the arteries cannot expand to meet that increased demand, and the heart muscle suffers from a lack of the necessary oxygen, called ischemia.  (This is the most common reason someone would have chest pain with exertion, also termed angina.)  Sometimes, a piece of these plaques can break off and become dislodged from the inner wall of the artery, travel downstream, and get stuck in a narrower part of the artery, causing a near-complete or complete cessation of blood flow to a particular part of the heart.  If prolonged, this can lead to infarction, or death of this part of the heart muscle: what is commonly known as a "heart attack."

So why do people get coronary artery disease?  Well, part of it is genetic; if your parents or siblings have coronary artery disease, you're more likely to suffer from it as well, and obviously you can't do anything about that.  But there are many modifiable risk factors for coronary stenosis, such as high blood pressure, diabetes, and smoking, that you can do something about.  And running helps with these factors: regular aerobic exercisers have lower rates of high blood pressure and diabetes, and are less likely to smoke.  But here's the kicker: despite the fact that distance running unquestionably reduces your risk factors for coronary disease, it may not actually reduce the chances of developing coronary disease.


CT scan reveals calcification of the coronary arteries.
photo: umm.edu
One of the problems with standard screening tests for coronary artery disease--namely, EKGs and stress tests--is that they are not particularly sensitive in detecting underlying coronary disease among fit individuals.  A routine exercise stress test aims to induce strain on the heart by gradually increasing the heart rate via exertion in a laboratory setting; patients are then assessed for symptoms of heart disease, or changes in blood pressure or heart monitor patterns.  For regular endurance exercisers, the limitations of this test are obvious.  If an athlete is increasing their heart rate via exercise on a daily basis without adverse symptoms, why would any abnormalities appear when she does it on a treadmill, in front of a physician?  However, in the past decade advances in technology have made high-resolution CT scanning widely available for the detection of underlying coronary artery disease.  A CT scan is not without downside--it does involve exposure to ionizing radiation, which is carcinogenic in high doses--but this modality can help identify at-risk individuals who might otherwise be missed by more traditional assessments of cardiovascular health.

Applying this test to an athletic population, researchers have discovered some surprising findings.  Despite having a lower incidence of hypertension, diabetes, and obesity, long-term marathon and ultramarathon runners actually have a higher incidence of coronary artery calcification than non-exercisers in the general population.  (Interestingly, runners who regularly train and compete at shorter distances do not demonstrate this finding.)  This paradoxical relationship has been reported as early as 2008, and has been validated several times since (including by yours truly and colleagues earlier this year).

Why does this happen?  We're not really sure, though several theories have been advanced that might account for this process.  One idea is that repeated high-intensity aerobic efforts subject the coronary vessels to more turbulent blood flow, which over time can lead to chronic inflammation and calcification.  Free radical formation, causing chronic oxidative stress, may also play a role. 

So, does this mean we should all stop running ultras?  Not necessarily.  No one has demonstrated as yet that this increase in coronary calcification leads to an increase in clinical signs of heart disease, or to an increase in mortality (we'll address this further in a subsequent post).  There is some thinking that the calcifications commonly seen in long-term distance runners are firmer and more stable than the softer plaque often seen in the general population, and therefore less likely to break apart and cause the downstream problems I talked about earlier.  Also, research demonstrates that long-term training leads to larger coronary arteries, with more ability to dilate (open up) than those in untrained subjects.  This might serve to counteract the narrowing effect of coronary calcification.  (If your hose is getting clogged, make the hose bigger, and water will be able to flow through more easily.)


OK, this isn't the most reassuring post of all time.  But let's sum up with what we actually know:

  • long-term endurance exercise reduces your risk of high blood pressure, diabetes, high cholesterol, and obesity.  Since heart disease is only one of the issues that can arise in people who suffer from these ailments, this fact alone is probably reason enough to keep training.
  • despite this, people who regularly train for and participate in marathons and ultramarathons appear to have a higher rate of coronary calcification than those who don't.  
  • this higher incidence of calcification may or may not be clinically relevant.  But all things being equal, you'd rather it wasn't there.
  • even runners with higher levels of coronary calcifications may not show signs or symptoms of disease, and standard screening tests may not pick up underlying disease in these people.
Therefore, my take-home point is not that we should all freak out and stop running.  But we should realize that we're not immune to coronary artery disease, even though we are invariably "healthier," on average, than non-runners.  For those of us entering our masters running careers, and who have been at this for several years or more, we should be cognizant of this risk.  Talk to your physician about the pluses and minuses of a CT scan of the coronary arteries, particularly if you have a family history of coronary artery disease in a close relative.  And check back next week when I'll tackle the "running versus mortality" question and try to debunk some of the negative press coverage you may have seen recently.

Tuesday, June 20, 2017

Merry Statesmas! My WS100 Picks and a Pre-Squaw GUR Top 50 Update


I'm recycling the title of this post from last year.  Let's get into it!

I've been way behind on the Gunksrunner Ultra Rankings this year, mostly due to finishing my exercise physiology coursework, but I finally got caught up in the past two weeks, and have a pre-States GUR Top 50 at the end of this post.  As such, though, I haven't been quite as immersed in results as in previous years, so my picks for this weekend's Big Dance are likely to be even less reliable than usual.  But you get what you pay for.  Which is nothing.  So here goes.

Ladies
Six of last year's top ten return, joined by a very deep field that includes ten of the current GUR top 50 (including six of the top 10), and twelve of the 2016 top 50 (including 10 of the top 20).  The depth of this group is frightening; while both the men's and women's fields have at least twenty solid contenders for those magical top-10 places, the talent and experience on the women's side might outflank the men, especially at the 100-mile distance.

1. Kaci Lickteig
Final 2016 GUR: 1
Current 2017 GUR: 5
2016 WS: 1
Western States does tend to look kindly on defending champions--think Krar, Olsen, Trason, and Jurek, to name just a few.  Whether the Pixie Ninja belongs among the all-time greats is still debatable, but the returning champ has three straight top-5 finishes here, and her buildup to this year's event looks awfully similar to last year.

2. Magdalena Boulet
Final 2016 GUR: 2
Current 2017 GUR: 3
2016 WS: DNF
The 2015 champ and UROY dropped early in last year's race, then gutted out a difficult fifth-place finish at Speedgoat later that summer.  She bounced back, however, with a strong second at North Face in December, and this year has looked very strong, placing second to Camille Herron at Tarawera and earning her ticket to WS with a T2 at Lake Sonoma.  She's got the speed, the experience, and the 100-mile chops to ascend the podium again.

3. Andrea Huser
Final 2016 GUR: NA
Current 2017 GUR: NA
2016 WS: NA
She's got wins or runner-up finishes at a dizzying array of Europe's most competitive trail ultras, including Diagonale des Fous, Lavaredo, Madeira Island, and UTMB.  We don't often see rookies or Euros atop the States podium--usually it takes a couple of tries to get it right--but she's not your average rookie.  Is she too much of a mountain specialist for this course, or does she have the wheels to hang with Magda, Kaci, and Camille when things start heating up on Cal Street?

4. Amanda Basham
Final 2016 GUR: 18
Current 2017 GUR: 9
2016 WS: 4
Speaking of wheels, I like the recent UROC champ to reprise last year's finish.  Undefeated in three ultra starts this year, though has yet to face a field of this caliber in 2017.

5. Camille Herron
Final 2016 GUR: 24
Current 2017 GUR: 2
2016 WS: NA
I gave a lot of serious consideration to picking Camille for the overall win.  Already this year she's beaten Magda at Tarawera, and may have already locked up Performance of the Year with her dominant win at Comrades two weeks ago.  (An honor she won in 2015, her first year in ultrarunning.)  However, she hasn't yet proven to be quite as dominant on the trails as she is on the roads, and this will be her 100-mile debut; besting a field of this caliber under those circumstances may be too much to ask, especially if there's any residuals fatigue from Comrades.  If anyone can pull at Walmsley on the women's side, though, it's definitely her.

6. Maggie Guterl
Final 2016 GUR: 17
Current 2017 GUR: 128
2016 WS: 8
She's lightly raced so far this year, having picked up wins at some smaller, short East Coast trail races, but she smoked a 14:47 at Brazos Bend in December.

7. Jacqueline Merritt
Final 2016 GUR: 69
Current 2017 GUR: 6
2016 WS: NA
Another East Coast stud, she already has four wins this year and a second-place finish at the Georgia Death Race to lock up her Golden Ticket.

8. Amy Sproston
Final 2016 GUR: 6
Current 2017 GUR: 109
2016 WS: 2
I picked Amy seventh last year and commented, "I feel like I actually might be selling her short here."  She went out and crushed a second place finish.  Naturally I've dropped her to eighth this year, so I fully expect her to win and make me look like an idiot.

9. Stephanie Howe Violett
Final 2016 GUR: 133
Current 2017 GUR: 16
2016 WS: NA
The 2014 WS champ missed most of 2016 due to injury but rebounded for ninth at North Face and then bested a solid field, including Camille Herron, to win at Bandera in January.  Definitely selling her short here.

10. Clare Gallagher
Final 2016 GUR: 13
Current 2017 GUR: 65
2016 WS: NA
Talk about selling short...she won Leadville last year in her 100-mile debut, but has flat speed honed during a stellar collegiate career, backed up with a fifth place finish at TNF in December.  I could easily see her in the top 3.

Hedging my bets
11. Meghan Laws (nee Arbogast)
12. YiOu Wang
13. Kaytlyn Gerbin
14. Nicole Kalogeropolous
15. Alissa St. Laurent

Lads
Eight of last year's top ten return, though unfortunately not defending champ Andrew Miller, recovering from injury.  Eight of the current GUR top 50 are in the field (including three of the top 5), and thirteen of last year's top 50, including eight of the top 20.  Add in several top-flight Europeans and you've got a very solid field of contenders...but absolutely nobody is picking an upset.

1. Jim Walmsley
Final 2016 GUR: 1
Current 2017 GUR: 3
2016 WS: 19
Allow me to become the 457th commentator to observe that the only person who can beat Jim right now is Jim.  His stunning 100 mile debut was one of the most electric performances of the year, notwithstanding the wrong turn at 91 miles that cost him the win and likely the course record.  Did you know that other than that wrong turn, Jim hasn't lost a race in over two years?  I could see him maybe blowing up if he is serious about chasing his stated goal--a sub-14:00 finish, which would better the course record by nearly an hour--but it's not likely.  And short of that, or injury, I don't see anyone in this field who can beat him.

2. Kyle Pietari
Final 2016 GUR: 23
Current 2017 GUR: 1247
2016 WS: 8
OK, I'm going straight chalk with my picks for the winners, but here's a little bit of a dark horse for you.  He backed up last year's top-10 with a second place finish at Leadville.  He's been quiet this year, with only one ultra finish back in March.  Is he ready for a huge breakout?

3. Alex Nichols
Final 2016 GUR: 12
Current 2017 GUR: 46
2016 WS: NA
Alex has a long history of stellar performances at huge ultras and other mountain races, including multiple wins at Pikes Peak, and has represented the US in the World Mountain Running Championships.  He made his long-awaited 100-mile debut last year with a win at Run Rabbit Run, and backed that up with top-five finishes at Speedgoat and North Face.  The WS course sets up well for people with Alex's particular skill set--climbers who have flat speed to burn.

4. Jeff Browning
Final 2016 GUR: 11
Current 2017 GUR: 25
2016 WS: 3
When you've been running ultras for fifteen years, it's hard to have a career year at 45--but that exactly what Jeff did last year, with a win at HURT, third at WS, and fourths at Hardrock and Run Rabbit.  He's undefeated in three low-key 50Ks so far this year.  It may be too much to expect a repeat of 2016, but I feel weird picking against him.

5. Chris Mocko
Final 2016 GUR: 29
Current 2017 GUR: 4
2016 WS: 7
He may have had the best 2017 so far of anyone in the field not named Walmsley: second at Way Too Cool, third at Sonoma, wins at Marin and UROC.  As long as he hasn't cooked himself too early in the season, he'll be heard from this weekend.

6. Jonas Budd
Final 2016 GUR: NA
Current 2017 GUR: NA
2016 WS: NA
I always have trouble picking the Euros (though I did hit Lorblanchet exactly last year, and wasn't too far off on Giblin) so who the hell knows.  But Jonas has the speedster pedigree of the Euros who usually perform well at States, and he was second to Walmsley at Tarawera earlier this season, though not really without shouting distance.

7. Ian Sharman
Final 2016 GUR: 3
Current 2017 GUR: 1528
2016 WS: 6
I'll pick him to finish in the top ten every year.  More dependable than taxes.

8. Thomas Lorblanchet
Final 2016 GUR: NA
Current 2017 GUR: NA
2016 WS: 4
Fourth in 2016, fifth in 2015.  Pretty safe bet he'll be up there again.

9. Brian Rusiecki
Final 2016 GUR: 2
Current 2017 GUR: 5
2016 WS: NA
The perennial UROY contender and 2015 GUR #1 makes his long-awaited WS debut.  Brian usually excels on more technical tracks, and so the WS trail might not quite be in his wheelhouse.  But he's incredibly smart and tough, and he comes in off one of the best stretches of his career, including his recent runner-up finish at Cayuga Trails.

10. Mark Hammond
Final 2016 GUR: 8
Current 2017 GUR: 57
2016 WS: NA
Maybe a little bit of a dark horse here, but I like his form recently, particularly a runner-up finish to Nichols at Run Rabbit (ahead of Browning), and a smoking 14:49 at the Salt Flats 100 in April.

Hedging my bets
11. Tofol Castanyer
12. Paul Giblin
13. Jared Burdick
14. Dominick Layfield
15. Zach Szablewski

Pre-Western States GUR Top 50 (as of 6/16)


Men
State
Points
Women
State
Points
1
Sage Canaday
CO
126.4
YiOu Wang
CA
191.5
2
Max King
OR
125.5
Camille Herron
OK
178.1
3
Jim Walmsley
AZ
118.5
Magdalena Boulet
CA
95.3
4
Chris Mocko
CA
107.1
Ladia Albertson-Junkans
WA
74.5
5
Brian Rusiecki
MA
96.3
Kaci Lickteig
KS
71.8
6
Tim Freriks
AZ
71.75
Jacqueline Merritt
GA
61.7
7
Hayden Hawks
UT
68.5
Sabrina Little
TX
59.25
8
Cody Reed
AZ
63.6
Courtney Dauwalter
CO
58
9
Chris Raulli
NY
55
Amanda Basham
UT
48.5
10
Tim Tollefson
CA
52.5
Marianne Hogan
CO
48
11
Dakota Jones
CO
45
Kaytlyn Gerbin
WA
46.8
12
Chikara Omine
CA
43.9
Hillary Allen
CO
46.7
13
Michael Owen
OH
43.5
Kathleen Cusick
FL
46.5
14
Matt Flaherty
IN
40.75
Camille Shiflett
WI
45
15
Justin Ricks
UT
40
Cassie Scallon
CA
43.7
16
Zachary Szablewski
WA
38.5
Stephanie Howe Violett
OR
40
17
Franz van der Goen
CA
38.2
Nicole Kalogeropoulos
TX
38.5
18
Masazumi Fujioka
WA
38.2
Megan Roche
CA
35
19
Ed Ettinghausen
CA
38.05
Rachel Drake
OR
34.5
20
Ryan Kaiser
OR
35.8
Ashley Nordell
OR
33.75
21
Dylan Bowman
CA
35
Devon Yanko
CA
33.6
22
Scott Trummer
CA
35
Dani Filipek
MI
32.5
23
Ronnie Delzer
TX
33.9
Janessa Taylor
OE
31
24
Matthew Thompson
VA
33.5
Gina Slaby
WA
30.6
25
Paul Terranova
TX
32.3
Shandra Moore
TX
30.2
26
Jean Pommier
CA
31.65
Julie Koepke
TX
29.9
27
Dominick Layfield
CA
31.2
Rachel Jaten
WA
28.9
28
Anthony Jacobs
TX
31
Sheila Vibert
VA
28.9
29
Travis Morrison
UT
29.9
Penny McPhail
CA
28.3
30
Ben Koss
CA
29.75
Caroline Boller
CAN
28
31
Cole Watson
OR
29.5
Meghan Arbogast
CA
28
32
Bob Shebest
CA
29.4
Molly Schmelzle
OR
26.9
33
Olivier Leblond
VA
28.6
Kirsten Hite
FL
26.3
34
Avery Collins
CO
28
Amy Macintire
TN
25
35
Ryan Bak
OR
27.25
Julia Stamps
CA
25
36
Jesse Haynes
CA
26.9
Rachel Entrekin
AL
25
37
Mario Martinez
CA
26.1
Bree Lambert
CA
24.9
38
Joe McConaughy
MA
25.025
Katalin Nagy
FL
24.9
39
Tyler Jermann
AZ
25
Jenny Hoffman
MA
24
40
Michael Daigeaun
PA
23.4
Alicia Hudelson
GA
23.9
41
Jason Schlarb
CO
23.05
Shawn McTaggert
AK
23.5
42
Ryan Ghelfi
OR
23.05
Meg Landymore
MD
23
43
Jean-Bernard Flanagan
IL
23
Chavet Breslin
CO
22.5
44
Matt Smith
TX
23
Karen Holland
CAN
22.5
45
Alex Nichols
CO
22.5
Amy Rusiecki
MA
22
46
Rob Krar
AZ
22.5
Camelia Mayfield
OR
21.9
47
Tyler Green
OR
22.5
Michelle McLellan
TN
21.5
48
Drew Macomber
CA
21.7
Addie Bracy
CO
21
49
Noah Brautigam
UT
21.7
Katrin Silva
NM
21
50
Patrick Caron
MA
21.5
Keely Henninger
OR
21