The Ketogenic Diet and Marathon Running

harlotscurse (65)in #ketogenic • 5 years ago (edited)

Ketogenic Marathon Running – 5

Keto Fry Up

On the question of the advantages and disadvantages of the Ketogenic Diet for the endurance athlete the jury is still out. For every Marathon runner, Ultra runner or triathlete promoting the Ketogenic Diet as the ideal diet for endurance sports, there is at least one arguing against it.

My own experience—after just six months of Ketogenic training—is encouraging but mixed. I adopted the diet on 1 December 2018. On 24 March 2019, I ran the Wicklow Gaol Break Half-Marathon in 01:23:21, which was slightly faster than my last two glycogenic Half-Marathons, despite a very hilly course and windy day. I finished fourth overall and first in the over-fifties. It was one of my best performances ever, even though it was well outside my PB of 01:14:32.

Wicklow Bay

At the time I considered this a spectacular vindication of the Ketogenic Diet. Six weeks later, however, I ran the Limerick Marathon in 02:58:15. That was more or less what I was aiming for—another sub three-hour Marathon—but it was hardly the ringing endorsement of the Ketogenic Diet I was hoping for. Although the course was challenging and undulating, the conditions on the day were ideal: cool and sunny, and with little or no wind. Nevertheless, I felt under pressure during the second half of the race and had to dig deep to keep up with the three-hour pacemakers. This was quite different from my experience in the Cork City Marathon in 2017, where I also ran with the three-hour pacemakers. On that occasion, I was never under any pressure. It was like a Sunday morning long run, and one of the easiest Marathons I have ever completed. My finishing time was 02:57:50. Limerick was much more difficult, but I cannot say how much this was due to the challenging course, how much to the fact that I was running a Marathon at sub 3-hour pace without the benefit of any carbo-loading, and how much to the fact that I had been following a radically new training program for only five months.

The last of these factors is probably significant. I switched to the Ketogenic Diet less than six months before running the Limerick Marathon. That is probably not ideal. The simple fact is that full keto-adaptation—by which I mean that the athlete has not only become fat-adapted in the normal sense of the word but has also trained his new cardiovascular system to be as efficient as possible—will probably take at least one year, if not longer. Back in 1993, when I first took up running, it took me ten months of serious training to get into shape to run a sub-three-hour Marathon. And it was only in my second season of training that I was regularly running faster than 5:00/K. In my first year, 5:15/K was my typical pace, while the pace of my long runs and recovery runs was generally slower than 5:30/K.

King John’s Castle and Thomond Bridge in Limerick

It is not realistic to expect your body to switch from glucose to fat overnight, allowing you to resume your normal training after a relatively short period of adaptation. Realistically, I expected that my first year as a ketogenic Marathon runner would resemble my first year—1993—as a glycogenic Marathon runner. Most of my running would probably be done around 5:00—5:30 per kilometre, a pace that I would normally consider pedestrian. I would feel untrained, with little spunk in my legs. I also expected that my first ketogenic Marathon would probably be no faster than my first high-carb Marathon (2:55:33), if not somewhat slower, bearing in mind that it would be taking place after just eighteen weeks of training on the Ketogenic Diet.

Training for My First Keto-Marathon

I found the transition from glycogenic training to ketogenic training very challenging. As I have already pointed out, my training pace took a severe hit—something many online coaches had warned me to expect. But this was the least of my worries. I also felt very leg weary throughout the day. After my workout, I felt tired and drained of energy for the rest of the day. Walking upstairs left me breathless. Cycling into town in the afternoon was exhausting. At night, I found it difficult to get to sleep, and woke up feeling restless several times during the night. Lying in bed, I frequently suffered from restless legs syndrome. And even when my legs were not restless, I was still getting up half a dozen times at night to urinate and to quench my thirst. As the weeks of training passed, I was also finding it increasingly difficult to meet my usual weekly mileage targets. Running was beginning to become a chore.

This was all in stark contrast to my experiences as a glycogenic Marathon runner. For twenty-five years, I was running around 120 K a week, but I always felt full of energy throughout the day. I slept well. I sometimes experienced restless legs syndrome at night, but only if I failed to properly rehydrate after a long run.

There was only one truly positive thing I could report about the switch: the anti-inflammatory effects of the Ketogenic Diet meant that even if my runs were leaving me drained of energy, they were not taking their usual toll on my body in terms of aches and pains, stiffness, and muscle soreness.

Patience

Among the many things I read online while researching the subject of ketogenic Marathon running, the following offered a glimmer of hope:

The HFLC [High-Fat, Low-Carbohydrate] strategy has been shown to increase the utilization of fat for energy, especially in long-term (20 months) fat-adapted athletes (Volek, 2015) ...

Once you are adapted to fueling yourself primarily on ketones for day-to-day living, you still need to adapt to performing optimally as an athlete fueled by ketones. This can take months, during which time your only progress will be in fat adaptation, not aerobic development, the ability to produce power, or the ability to achieve faster paces. (Carmichael & Rutberg)

This was actually quite comforting to me, and it chimes with my first few months of Marathon training on the Ketogenic Diet. But note that the authors believe that an adapted ketogenic athlete is fueled by ketones. That is simply not true. Although your skeletal muscles do metabolize ketones for energy when they are first starved of glucose, they soon switch to free fatty acids, leaving the ketones for the brain and other organs that cannot metabolize free fatty acids:

Although skeletal muscle has the capacity to take up and oxidize ketones, it appears that over time muscles switch to using fatty acids provided from blood and probably muscle triglycerides. This process, a key element of keto-adaptation, allows ketones to achieve levels in the blood that allow them to meet most of the brain’s fuel needs. (Volek & Phinney 2012:30)

The conclusion Volek et al draw from the study cited by Carmichael & Rutberg above reads:

Compared to highly trained ultra-endurance athletes consuming an HC [High-Carbohydrate] diet, long-term keto-adaptation results in extraordinarily high rates of fat oxidation, whereas muscle glycogen utilization and repletion patterns during and after a 3 hour run are similar. (Volek et al 100)

The key phrase, perhaps, is long-term. In Volek’s study, the subjects were adapted over an average period of 20 months, ranging from 9 to 36 months.

Mileage and Endurance

When I first took up Marathon running back in 1993, I tried to educate myself on the science behind the sport. Among the most influential things I read was a quotation from Dr David L Costill, one of the pioneers into what is now called sports medicine. It was in Bob Glover and Pete Schuder’s classic text The New Competitive Runner’s Handbook, which was the first book I bought on the subject of Marathon running:

According to Dr. Costill: “There is a point of optimal distance that will cause the body to adapt to its full aerobic capacity. Based on laboratory observations, we have concluded that the mileage needed for the maximum training benefits varies between 60 and 90 miles [96-144 km] per week. There is a point of diminishing returns, a point at which you can increase weekly mileage but see little or no improvement in performance.” For the average runner, Costill believes that the mileage limit should be 50-75 [80-120 km] miles a week, since “the amount of physiological improvement beyond that is almost insignificant.” (Glover & Schuder 73)

If anything, Dr Costill’s opinion on this subject has become even more conservative since 1993, when I first read those words. In an article by Jason Karp in the May 2007 issue of Running Times, he is quoted as saying:

“When you go from an untrained state to a trained state, running 30 to 40 miles [50-65 km] per week, VO2 max and the measurements commonly taken from muscle biopsies increase, but as you move up to about 60 miles per week [96 km], things start to plateau,” Costill says. “The exact mileage at which this plateau occurs depends on the individual, but beyond about 60 to 70 miles [96-112 km] per week, there’s not much change taking place.” So, if VO2 max and muscle cellular adaptations plateau at about 70 miles per week, why do people run much more than that? “I really have no idea,” says Costill. “People who run 5Ks and 10Ks still need a lot of speed, and when you run 120 or 130 miles per week, you can’t do much quality.” (Running Times, May 2007, p 40)

It was on the basis of the advice I read in The New Competitive Runner’s Handbook that I tailored my Marathon training programs to a target of, on average, 120 km [75 miles] per week. I felt that I could handle that amount of mileage, and it would ensure that I had safely reached Costill’s plateau. Current research, however, suggests that even this may be about 8-24 km too much.

When I first made the switch from glycolysis to ketosis, I continued to run my usual 120 km per week—including easy long runs of three hours’ duration. Or, rather, I tried to. I actually found the transition very difficult. Previously, I would wake up in the morning fully refreshed. I would bounce out of bed full of energy and think nothing of heading out for my run at 6:00 am. And even after a tough run, I would still be full of energy for the rest of the day. But as I became keto-adapted, this changed. I found it required much greater effort to run at the same pace as before. I woke up tired and lethargic. I generally put off my run till after I had had my morning coffee. And after my run I would feel tired and drained of energy for the rest of the day. Although I was putting in the hours, I simply wasn’t reaching my target of 120 km per week.

I did not understand why this was so. Then, after returning from my first ketogenic race—the Wicklow Gaol Break Half Marathon—I found that my legs just did not want to follow my usual schedule. I would set out on a scheduled three-hour long run, but after two-and-a-half hours I would be too tired to do much more. My ninety-minute workouts shrank to 75 minutes. Even my sixty-minute recovery runs felt at least fifteen minutes too long.

Then I had a brainwave: Is it possible that this lethargy or lack of energy is simply due to the fact that I am running too much mileage. I remember many years ago when I tried to run 100 miles (160 km) a week. I was so tired all the time that I just could not do any quality runs. I was no longer enjoying my running. It had become a chore rather than a joy. I abandoned the experiment after just a few weeks and went back to 120 km a week, and my energy levels returned. That was exactly how I felt as a ketogenic runner trying to do 120 km per week.

So, I ask myself: Is it possible that when one is keto-adapted and in ketosis, one only needs to run, say, 80 km a week to maximize one’s aerobic capacity? Is it possible that there is something about the physiology of ketosis, keto-adaptation and fat metabolism that allows one to achieve the same training benefits as in glycolysis but with considerably less mileage?

I have searched online to see if anyone else has noticed or hypothesized something along these lines, but so far without any luck. Perhaps this is just wishful thinking on my part.

Electrolytes and Ketogenic Running

But let’s not be too hasty. Just recently I watched two interesting videos by Dr Nick Zyrowski, one of the popular promoters of the Ketogenic Diet on YouTube. Is it possible that my leg weariness and other problems are simply symptoms of electrolyte deficiency or imbalance?

Electrolyte Imbalances: Don’t Do What I Did!

Causes Of Electrolyte Imbalance

One of the characteristics of the Ketogenic Diet is the lack of water retention. As water is flushed out of the system, it carries with it the water-soluble electrolytes (sodium, chloride, potassium, calcium, magnesium, phosphate, sulphate and bicarbonate). If you adopt this diet, then you must not only consume more water than before, you must also ensure that your electrolytes are being replenished on a daily basis. Combine the Ketogenic Diet with Marathon training, intermittent fasting, and drinking filtered water—as I was doing—and you are only compounding the problem.

For the first five months after switching to the Ketogenic Diet, I believed that my diet was providing enough of these electrolytes to prevent any deficiencies or imbalances. After watching Dr Zyrowski’s video, however, I had a change of heart. The first two symptoms of an electrolyte imbalance that he mentions are muscle fatigue and poor muscular endurance. I had those in spades. He also mentions frequent thirst and urination: as I described above, I was getting up several times a night to drink water and urinate. I also experienced some muscle spasms in my lower legs—but only at night, not during exercise—bowel irregularity, and numbness and tingling.

Since watching those videos, I have been supplementing my diet with electrolyte powder on a daily basis. I have experimented with a few varieties. Dr Berg’s Electrolyte Powder is tailor-made for the Ketogenic Diet, but I have to have it shipped from the US, which is not very economical. I will probably settle on Bulk Powders, a British product which contains nothing but the first seven electrolytes mentioned above, and which I can source locally and inexpensively here in Dublin.

Bulk Powders’ Electrolyte Powder

Since adopting this new policy of aggressively replenishing my electrolytes, the symptoms I spoke of have all but disappeared. I am now sleeping soundly with few or no interruptions. I don’t feel as tired or as leg weary as before—though I have not yet recovered the bounce-out-of-bed energy levels of the past. I haven’t experienced any muscle spasms or restless legs syndrome during the night. Even my bowel irregularities are on the wane. It’s all very encouraging.

An New Experiment

In that article by Jason Karp from which I quoted Dr Costill, another famous exercise physiologist, Jack Daniels, had this to say on the question of weekly mileage:

“The best answer might be to do as much as you can without losing interest or getting sick or injured.” (Running Times, May 2007, p 39)

My instinct, however, is to take the opposite tack: run as little mileage as is necessary, but run it as fast as you can. Being of a scientific bent, my response is: Let’s do the experiment. So, for my next big race—the Clonakilty Half-Marathon on 30 November 2019—I will cut my weekly mileage from my usual 120 km (a target I simply wasn’t reaching anymore) to about 80 km—the lower bound of Dr Costill’s recommended mileage for the average runner. Actually, my plan is to cut my schedule to about 6 hours of running, which should correspond to about 80 km per week.

I originally planned to do long runs of no more than 2 hours, but it may be wiser to alternate an easy week in which I run long for 2 hours and a hard week in which I run long for 2:30. The long run is a crucial part of a Marathon runner’s schedule, but it may be less crucial for the ketogenic trainer. One of the key purposes of running long in the first place is to train your body to burn fat and save glycogen: but this is something that a ketogenic runner is doing twenty-four hours a day. I will have to research the long run further. In the meantime, I have pencilled in the following weekly schedule (including my former glycogenic schedule for comparison):

Schedule	Long Run	Recovery	Sprints	Endurance	Recovery	Speed	Recovery	Total
Glycogenic	3:00	1:00	1:30	1:30	1:00	0:40	0:30	9:10
Ketogenic Easy	2:00	0:30	1:00	1:00	0:30	0:40	20	6:00
Ketogenic Hard	2:30	0:30	1:00	1:00	0:30	0:40	20	6:30

Sprints means a fast endurance run interspersed with thirty-second bursts of sprinting every five minutes or so.

Speed means a forty-minute workout on the treadmill, including 8 K at 3:30/K.

Over the past month or so, then, I have been running much less mileage than I did during the first five months of my ketogenic Marathon training. During that month, I have also been taking electrolyte supplements. And as I described above, many of the negative symptoms of my ketogenic Marathon training have disappeared or become significantly less severe. How much of this is due to the reduced mileage? How much to the electrolyte supplements? How much to the simple fact that as the months pass, my body is becoming increasingly adapted to this new regimen? It is probably safe to assume that all three have played their part.

I’m in this for the long haul.

References

Bob Glover, Pete Schuder, The New Competitive Runner’s Handbook, Penguin Books, London (1988)
Chris Carmichael, Jim Rutberg, Should Endurance Athletes Go Keto?, CTS, Train Right
Jeff S Volek et al, Metabolic Characteristics of Keto-Adapted Ultra-Endurance Runners, Metabolism: Clinical and Experimental Volume 65, Issue 3, pp 100-10, Elsevier (2016)
Jeff S Volek, Stephen D Phinney, The Art and Science of Low Carbohydrate Living, Beyond Obesity LLC (2011)
Jeff S Volek, Stephen D Phinney, The Art and Science of Low Carbohydrate Performance_, Beyond Obesity LLC (2012)
Jacob Wilson, Ryan P Lowery, The Ketogenic Bible: The Authoritative Guide to Ketosis, Victory Belt Publishing, Las Vegas (2017)