Friday, August 26, 2011

Do Intervals Require More Effort?

At our cross country practices I’ve noticed that we are running a lot more interval workouts than we did last year. An interval session includes (1) a warm up period at easy pace, (2) a series of short, fast runs with rests, and (3) a cool down period at easy pace.

The series of short, fast runs with rests, or intervals, can vary widely in repetition and distance (typically inversely proportional), but commonly are run at fast pace. Typical examples of interval sessions (in meters) are: 20x100s, 16x200s, 10x400s, 6x800s or 3x1600s. Paces of course depend on athletic ability, but typically easy pace at warm up/cool down is approximately 10 min/mile and interval paces range roughly from 5 min/mile to 7 min/mile, the shorter the interval distance the faster the pace. The rest periods in between intervals can range from complete rest to walking to very easy jog, about 12-16 min/mile.

In contrast to interval workouts, our distance runs are at typically easy pace throughout, say 9-10 min/mile. Both types of workouts last about the same amount of time, approximately 1 hour. Our coach believes as do I that once a base foundation of fitness has been established (through consistent distance runs), then workouts should focus more on interval training to adapt runners to faster paces.

Whatever the effect of interval training has on performance, they definitely feel harder to do than a slow, steady state distance run. Let’s see if the math supports this feeling, shall we. Energy rates (cal/kg/hr) are derived by Ainsworth et al (1). Effort will be based on my body weight, 79 Kg (175 lb). For those that care, I mean kilocalorie when I say cal. If this loses you, forget about it because it’s a relative comparison anyway.

Let’s compare my effort for a 6 mile distance run @ 9 min/mile pace (11 cal/kg/hr) versus the following 6 mile interval session:

• 2 mile warm up @ 10 min/mile (10 cal/kg/hr)

• 12x Quarter Mile Loop
Sprint 5.5 min/mile (18 cal/kg/hr) for ¾ loop
Walk/Jog 16 min/mile (6 cal/kg/hr) for ¼ loop

• 1 mile cool down @ 10 min/mile (10 cal/kg/hr)

Math for Distance Run, 6 Miles Total

Time = 6 miles x 9 min/mile = 54 minutes

Energy = 11 cal/Kg/hr x 79 Kg x 54 min x 1 hr/60 min = 782 cal

Math for Interval Run, 6 Miles Total

Warm Up Time = 2 miles x 10 min/mile = 20 minutes

Warm Up Energy = 10 cal/Kg/hr x 79 Kg x 20 min x 1 hr/60 min = 263.3 cal

Sprint Time = 12 x 0.1875 miles x 5.5 min/mile = 12.375 minutes

Sprint Energy = 18 cal/Kg/hr x 79 Kg x 12.375 min x 1 hr/60 min = 293.29 cal

Walk/Jog Time = 12 x 0.0625 miles x 16 min/mile = 12 minutes

Walk/Jog Energy = 6 cal/Kg/hr x 79 Kg x 12 min x 1 hr/60 min = 94.8 cal

Cool Down Time = 1 mile x 10 min/mile = 10 minutes

Cool Down Energy = 10 cal/Kg/hr x 79 Kg x 10 min x 1 hr/60 min = 131.67 cal

Total Time = 20 + 12.375 + 12 + 10 = 54.375 min

Total Energy = 263.3 + 293.29 + 94.8 + 131.67 = 783.06 cal


Comparing these two 6 mile runs, they both require the same amount of time within 1 minute and they both require the same amount of energy within 1 cal. From a time, distance and energy perspective, the distance run is the same as the interval run. But I agree with coach, interval running makes runners faster!

(1) Ainsworth BE, Haskell WL, Leon AS, Jacobs DR Jr, Montoye HJ, Sallis JF, Paffenbarger RS Jr. Compendium of Physical Activities: Classification of Energy Costs of Human Physical Activities. Medicine and Science in Sports and Exercise. 1993: 25: 71-80.

Sunday, August 21, 2011

New Balance Minimus Trail

These are pretty good looking shoes, no? I picked them up Saturday afternoon on an impulsive buy. Amy and I were running errands at a strip mall. On a whim, we stopped in the local sporting goods store to see what kinds of running shoes they were selling. To my surprise, we found the New Balance Minimus Trail Shoes in the Fashion section. It's not your typical ubiquitous cushioned running shoe. Rather, it's a light weight, minimal cushion, minimal heal minimal shoe. And I knew it was truely a minimal shoe when I saw the nonminimal price tag, $100. And yet, I was smitten.

My typical shoe size is 10 1/2. This size felt a bit snug. The cliche that came to mind was "fit like a glove", well, maybe the kind of glove OJ Simpson would wear. So I tried a size 11, but it seemed too loose in the heel and there was a lot of "extra" sock lining in the toe box. And the tightness was still there. It was the black strap across the forefoot at the toe base that was causing the tightness across the width. The 10 1/2 felt better without the extra lining material. Maybe the shoe would break in. Maybe it was supposed to fit tightly. I rationalized it until I was ready to plop my debit card on the counter. I loved the look of these shoes so much that I wore them out of the store.

Later in the day I went for a run, about 5 miles. The run felt fine enough, but I was happy to kick off the shoes afterwards. And I wondered, if 5 miles in these shoes put 1 blister on a toe, what would a long run do? The shoes went back to the store. Maybe next year's model will fit better. Dang, will I ever get the hang of this product review/company affiliation thing?

Monday, August 15, 2011

VFF = Transition to Footwear

Lately, I've been questioning my motives.

Example 1:

I ran 13.1 miles a few weeks ago, my first longish run since last November. My barefeet handled it pretty well, but they were getting tender in those last few miles and my feet definitely didn't feel like putting in anymore miles. Would it have been better if I ran shod? Could I have run longer?

Rambling in my head:

A couple of years ago, I was excited to discover that shoes don't necessarily improve the running experience. Running barefoot is an option. It's an option. It's not necessary, though. Sounds weird to say that. Why would I even have to admit it? Some conditions, like distance, weather and surface, shod is better for me. I believe I would have hated the hills less at the Flying Monkey marathon if I wasn't so concerned about how rough the ground felt.

Example 2:

Last week at XC practice, one of the kids asked coach if they could run barefoot. Coach said no and for good reason. The state of Tennessee mandates that middle and high school XC runners have to compete with shoes on their feet. Coach wants kids to train with shoes since that's how they will race. I wish this rule didn't exist. It feels awesome to run skin to ground on the XC course. There's less weight on the foot and foot landings are more stable on the bumpy surface. I feel a bit guilty about having an unfair advantage.

Rambling in my head:

Frankly, I've always been more comfortable with ground feeling than the feeling of social angst in my head from being one of few not wearing shoes. I'm ready to try and conform to the group.

Before practice today I dug out my VFF shoes from under the bed and wiggled my toes into them. I ran in shoes for the first time since January. I'm transitioning to footwear. I'm not ready yet for those cushy wedges. I may never get there. The VFFs are a start.

Hello, I'm Kelly. I'm a recovering barefoot fanatic.

Thursday, August 11, 2011

My Public Apology to Anthony Colpo


I was surprised and kind of flattered in a weird way (you are the author of the ground breaking book “The Great Cholesterol Con” after all, which I now must read) that you wrote a long post in response to my comments to Castle Grok:

Reader Mail: Jimmy Moore, Michael Eades, Angry Dick, and Other Assorted Fat Loss Failures

I think I was among the “Other Assorted Fat Loss Failures”. I’m also flattered to be thrown in the same ring as Jimmy Moore, Dr. Eades and Richard Nikoley, but let’s overlook that for now.

My internet writing style has been described by others as polemic. I tried to objectively respond to Castle Grok, but perhaps it was polemic given your response to it. As you pointed out I didn’t fully read both parts of your post on low carb athletes. I lost interest after I didn’t agree with your account of how Phinney performed his first study.

However, now I’ve gone back and fully read both parts, and I think we can agree more than we disagree. I am sorry for characterizing your post as misrepresenting based on one oversight. Let’s be clear on the points where I think we agree, especially regarding my post that you referenced:

About Phinney’s first study, I said:
“It would seem that keto-adaption greatly improved endurance, but the results were confounded by the fact that the average test subject lost about 10 Kg of body weight. Despite wearing loaded backpacks to equal their weight loss, the subjects had greatly improved exercise efficiency as measured by oxygen consumption decrease.”

About the cyclist’s study, I said:
“Despite the apparent success of Dr. Phinney's studies, I am still nagged by the effect of exercise intensity on the bodies’ ability to burn fuel from fat. In the middle of the 2004 paper he states:

"...high carbohydrate diets might be more effective in short-term tests of high-intensity exercise..."

And Dr. Phinney's concluding statement includes a caveat:

"...anaerobic (ie, weight lifting or sprint) performance is limited by the low muscle glycogen levels induced by a ketogenic diet, and this would strongly discourage its use under most conditions of competitive athletics."”

About Jonas Colting, I said:
“ Jonas Colting is an example of a very competitive, professional triathlete who embraces low-carb-high-fat nutrition. He has been interviewed by Jimmy Moore and posted on Mark Sisson's site. It's clear though that he doesn't strictly follow low-carb-high-fat nutrition. As he said, all rules are thrown out on race day. He calls it "train low, race high", in reference I think to muscle glycogen. He even is sponsored by the sugary drink manufacturer "Red Bull". However, he does say that his carbohydrate consumption is "a far cry" from the typical amount recommended by Swedish nutritionists for athletes, about 10 grams per Kg of bodyweight, or about 800 grams per day.”

Finally, I think we have common ground in my conclusion. I said:
“So it seems that some low carb runners like Kent, Cynthia and David correlate well with Dr. Phinney's research, as long as intensity levels are low to moderate. And Dr. Phinney isn't the only researcher to clinically show fat-adaptation doesn't impair endurance. Scientists at the University of Cape Town have published similar results. But it also seems unavoidable that competitive endurance relies at least partially on carbohydrates as per Jonas and Mark. I expect there will be more to say as I do personal experimentation. Til then.”

Let me repeat my final conclusion: "...seems unavoidable that competitive endurance relies at least partially on carbohydrates...". Can we agree on that middle ground?

Best Regards,

Tuesday, August 9, 2011

Driving Traffic and Bad Karma

When I bothered to check out the stats on my new blog tonight, I was kinda surprised by how high the numbers jumped up. I was getting a lot of traffic from:

Interesting, I thought. If you don't know Anthony Colpo, he's the author of "The Fat Loss Bible" and "The Great Cholesterol Con". Personally, I haven't read either book, but I've seen recommentations by Paleo bloggers to read "The Great Cholesterol Con". Anthony Colpo was cited in the comments of the interview below.

I scanned through the cited post, reading some parts more carefully than others. I commented back. One of my observations was accurate, the other not so much. My bigger mistake was using some negative terms to describe parts of the post like falsely reports and misrepresents. I should have known better, negativity only breeds more negativity. This is one of my character flaws that I've recognized for many years, and my sarcasm easily displays itself in electronic form.

Anthony ripped me a new one. You can read it for yourself if you are curious, but if there are kids in the room, beware of some nudity. Somehow, he got the idea that I've been a low carber for years and poorly performed in the 2004 Chicago marathon (although 3:13 isn't all that bad for a recreational runner) due to a low carb diet. Actually, I just started eating low carb in March of 2011. For the record, Anthony could be spot on about athletes needing carbs for performance. I don't know. But I'm curious if conventional wisdom has it right or wrong, so I'll continue on a path of self experimentation and reading about others experiments.

I appreciate getting the traffic boost(I went from an Alexa global ranking of 14 million to 10 million, woohoo!), but I apoligize for spreading bad karma. Something else to work on.

Friday, August 5, 2011

Got Sugar?

How typical it is for a long distance runner to ask themselves this question, "Do I need more sugar?" I've never seen a major half or full marathon that didn't have frequent aid stations with a sugar drink like Gatorade, those sugar gells called Gu or even a natural sugar source like orange slices. But how much sugar does a long distance runner need? Is any sugar consumption necessary?

I've been trying to understand the answers to these questions since I recorded my blood sugar readings last weekend while running a half marathon distance. You can check out that post for the details, but here's the chart:

I fully expected blood sugar levels to drop throughout the run. In a keto-adapted state from a low carbohydrate diet, I assumed fat would be my primary fuel as muscle glycogen levels should have been relatively low. I don't know the ratio of fuels from fat vs. glucose, but I was surprised that blood glucose levels were consistently higher from the baseline inactive start. If I wasn't getting much glucose from dietary carbohydrates, then where was that glucose coming from that caused the higher readings? The search for an answer resulted in googling a lot of words starting with the letter "g".

It's probably safe to say, or even perhaps obvious to say that the increased blood glucose was a hormonal response. Running is an exercise that quickens the heart rate, causes heavy breathing and sweating. In short, it's stressful. Adrenal glands respond to stress by releasing epinephrine (adrenaline) into the bloodstream. This triggers the secretion of the hormone glucagon from the pancreas.

Glucagon is the opposite hormone of insulin. Insulin acts to lower blood sugar, glucagon acts to raise blood sugar. Glucagon works to raise blood sugar by two mechanisms. First, it converts stored glycogen in the liver into glucose and releases it into the bloodstream for fuel. This process is called glycogenolysis. Second, as glycogen stores are depleted in the liver, glucagon then synthesizes glucose from noncarbohydrates like lactate, glycerol (the backbone of fatty triglycerides) and amino acids (proteins). This process is called gluconeogenesis.

Besides glucagon, another hormone released from adrenal glands in response to stress is cortisol. Cortisol also increases blood sugar by gluconeogenesis. Research has shown that cortisol enhances glucagon stimulation of gluconeogenesis. I found one ultra running site that suggested that cortisol doesn't affect the body until about 15 miles of running. If this is accurate, then my increased blood sugar from 3 miles on would be only due to the effects of glucagon, and most likely from the gluconeogenesis mechanism as my store glycogen levels were relatively low.

I especially like Wikipedia's description of gluconeogenesis, describing it as a highly endergonic process. Dang, there's another new word I had to Google:

By thermodynamic standards, work, a form of energy, is defined as moving from the surroundings (the external region) to the system (the internal region). Thus, an endergonic process, as contrasted with an exergonic process, is one wherein the system absorbs energy from the surroundings. As a result, during an endergonic process, energy is put into the system.

Doesn't that sound like a smart, efficient way to fuel a run?

Leave it to Jimmy Moore to explain gluconeogenesis in his special way:

Getting back to the original question, got sugar? In the diet I don't think sugar is necessary. The liver makes sure our body has glucose. If body tissues are in a glycogen depleted state, then the mechanism is gluconeogenesis: converting fats and proteins to carbohydrates.

Asked a different way, should dietary sugar be avoided? I think so. Carbohydrates put glucose into our bloodstream and elevate hormonal insulin levels. If muscle tissues are insulin resistant, then that glucose is stored as fat. No runner wants to be fat, it slows em down.

But you might say, "Kelly, I eat plenty of carbs and don't get fat." God love ya for being glucose tolerant. However, I would still suggest that reducing the carbohydrates in the diet will adapt the body to fuel with fat instead of the limited storage of glycogen. Speaking for myself, I have plenty of fat storage to fuel a run.

But you might also say, "Kelly, I run a lot further distances than a half marathon, try 100 miles." I don't have a response to this, yet. I plan on conducting more running trials with blood sugar monitoring, and my goal is to discover what happens to my blood sugar at longer distances. But I have never run a distance longer than the marathon, and I'm not sure I plan to. I'll leave that experiment to some other guinea pig.

Tuesday, August 2, 2011

Blood Glucose Testing During 13.1 Mile Run

Let me start by saying "No, I didn't run with a needle". But the thought crossed my mind, maybe next time. I'm not diabetic, so blood glucose testing is foreign to me. The idea to test blood glucose in response to certain stimuli came from guys like Jimmy Moore and Kent Altena. But rather than test my body's response to food, I was curious to see how it responded to exercise. I've posted before about keto-adaption and exercise. I thought I'd do my own experiment.

I've been following a low carb diet since March, defined by keeping my average carb intake under 100 grams. In the last month I started running again after a four month lay-off from an ab muscle pull in January. During those runs I have not experienced dizziness or excessive fatigue. I haven't drank Gatorade or ate Gu or Clif bars. Oh crap, so much for getting those companies to sponsor my blog. Anyway, it makes me wonder how far I can go on minimal outside fuel. Said another way, how far can I go on my internal body fat and glycogen fuel?

Last Saturday I ran my longest run since my last marathon in November 2010. I ran an approximate 1.5 mile loop around my neighborhood 8 times. I added a little extra on the end to make it a half marathon run, 13.1 miles. I chose a short loop in part because it gave me the opportunity to run by my house several times. I stopped at roughly 3.1 mile intervals to measure my blood glucose. Inspired by Moore and Altena, I was curious what the glucose fuel gauge needle looks like on a long run.

The chart below shows my nutrition leading up to the five days before a longish run, 13.1 miles.

I definitely followed a low carb diet in the previous week to the run, averaging less than 10% carb calories and over 60% fat calories. My diet for the last 5 months was similar, just not tracked consistently to show the stats. So I'd say I was keto-adapted as Dr. Stephen Phinney has described.

The run is charted below based on data collected on my Garmin 305. Total running time was just under 2.5 hours for an average pace of about 11 minutes/mile. It was a pedestrian pace, but hey, look at those hills in my neighborhood. My average heart rate was 136 bpm, or 70% maximum heart rate, so it was a decent effort for me.

So what about blood glucose you might ask? Well, here's the chart. The initial reading before the run was taken at 7 AM after an overnight fast. During the run, I only drank water, about 1.5 liters total. I suppose I expected ignorantly that sugar levels would drop throughout the run, but they didn't. They jumped up, rather consistently. About an hour after the run, my blood glucose returned to more normal levels, 91 mg/dL. A quick Google search suggests that these results could be explained by gluconeogenesis. I welcome comments from those folks that would like to explain what happened.

For those that are curious here's how I measured my blood sugar: