Welcome to Straight Talk on Health. I’m your host Dr. Chet Zelasko. Straight Talk on Health is a joint production with WGVU in Grand Rapids MI. I examine the practical application of health information. Nutrition. Exercise. Diet. Supplementation. I look at the science behind them and let you know whether it’s something to consider or not. You can check out other things that I do on my website Drchet.com and sign up for my free emails.
In late April, the official world’s record for the marathon, 26.2 miles, was broken by runners in both the male and female marathon. More than that, it was shattered by three male runners and one female runner. The male time was 1:59:30 while the female time was 2:15:41. In actuality, the world record and 2-hour mark was broken in an unofficial marathon run on a track under ideal conditions by another runner 5 years before that. But running under track conditions, much like breaking the 4-minute mile was, is different than running in a race on the road.
While reading about the prep for the race, much was made about the weight and construction of the running shoe. It weighed in at just 97 grams or about 3.2 ounces with a variety of other features to make the shoe strong and durable. I checked the weight of my new running shoes. They are a dream to walk in and will be better when I finally start running again.My running shoes weigh in at a whopping 339 grams—almost 3.5 times the weight of his shoes! That works out to about 4 ounces per shoe heavier, every step, for 26.2 miles if I were to run that far again. The scientist behind the development of the shoe said they considered every nanogram to make it the lightest shoe ever. That’s one billionth of a gram!
While the shoe is important, it is the training that makes the runner elite. I have no doubt they used the most sophisticated form of interval training to train the runners. Many people think that high intensity interval training is something relatively new. Fact is, interval training has been around more than a century.
When I was thinking about the marathon record, it reminded me of an article I wrote for a running column when I lived in Indiana. In that my post-doc was with one of the leading researchers on muscle metabolism, I took an interest in interval training. It just wasn’t developed 10-15 years ago as the recent emphasis on high intensity interval training (HIIT) might lead you to believe. It was developed in the early 1900s and then perfected over time as the technology to actually test what was going in the muscles was developed. It all revolves around something called the lactate threshold and recovery time. Let’s talk a look but understand, I’m going to simplify the biochemistry as much as I can to make it easier to understand.
The preferred fuel for exercise is glucose. Recent attempts to train to use fat, in the form of ketones, as fuel has not proven to be successful in helping athletic performance. It was, is, and, unless something else is discovered, always be about using glucose as a fuel.
When you begin to exercise, like going out for a walk, you’ll use a combination of fat and carbohydrate as a fuel. If you accelerate to a jog, the needle starts moving toward more CHO then fat as a fuel. When you break into a reasonably paced run, it moves further toward CHO. When you move to a 5K race pace, it moves all to CHO. How much faster you can run and maintain that race pace depends on your ability to transport pyruvate into the mitochondria to continue to make ATP inside the mitochondria. If the rate of pyruvate is too high, it’s converted into lactic acid instead. You may have never heard about pyruvate but I’m betting you have learned about lactic acid. As lactic acid builds up, if the rate gets too high, the exercise pace can’t be kept and performance is diminished.
How can you run faster? You have to RUN faster. Obvious, right? Stated better it should be you have to train to run faster. To do that, you need interval training. We know that HIIT is a method of interval training that involves max effort for 30-90 seconds with 3-4 minutes of rest. Why that amount of rest time? That’s how long it takes the muscles to recover from the lactic acid build-up and restore normal GLU metabolism. That’s nice but it won’t really help in a 5K or longer with the exception of a final sprint. It was really designed to see what benefit it might have for those who want put in as little time as possible in hard effort. Research shows it can benefit those with diabetes and pre-diabetes.
The goal of interval training is to increase stamina. Stamina is maintaining a higher effort for a longer period of time. There are dozens of programs that can do that but I’ll focus on three approaches. I’ll use running as an example but any aerobic sport like X-country skiing, swimming or cycling can use the same concept.
The first approach is to increase speed. If we use a 5 or 10K road race, that means we would probably use 200 to 400 meter repeats with rest intervals between. The rest time would be longer between 2-3 minutes. Again, that will allow time for the lactate to be converted to a form that can be used as energy. Remember that pyruvate stuff? Back into that form. Someone might do 200 meters at 30-60 seconds faster than their race pace for those intervals and just walking around to recover—never flopping on the ground because that means the effort is too high. Repeat 8 times after a warm up and cool down and you’re done.
Second would be 800 meter repeats at 15-30 seconds faster than race pace with 1-2 minutes rest between repeats. Again, that amount of rest allows complete recovery.These can be the most grueling because you are really pushing that lactate threshold. The rest interval is shorter to push that threshold further to increase stamina.
Third, and this is one I learned from a mentor during my post-doc, is to run half-mile to one mile repeats about 30 seconds slower than projected race pace. The key is that you only rest for 15 seconds before starting the next interval. When I was training, I would do those for 5 miles worth of intervals. They are called aerobic intervals because that’s all the time—15 seconds—it takes to recover the aerobic energy system. I use this approach now walking as I’m slowly getting back to jogging again.
There you have it. I have no doubt the athletes that broke the world marathon record used each form of interval training. The pace would be a whole lot faster than you or I could manage but the rest time would not change for each time. If you want to run faster, training the energy system to run faster is the key.
But don’t underestimate how it can help your fitness level if you have no intention of ever running or even walking more than your normal 2 miles per day. I adapted something I read by a trainer to improve my speed as well. They recommended walking at a normal pace for 2 minutes. Then for one timed minute, walk faster than normal. I open up the floodgates and walk as fast as I possibly can. You don’t have to do that but you can walk faster than normal for one minute. Then, go back to a normal pace to recover and repeat it throughout the entire walk, jog or run. It will improve your fitness level without any change in the distance you walk. Just make sure your doctor is good with you walking faster to get fitter. If you’re going to walk anyway, you might as well shake things up a little and get more benefit. You’ll also burn more calories as you do. And that’s how you can train like a marathon runner when you take your next walk.
That’s all the time I have for this episode. If you like this podcast, please hit the share button and tell your friends and colleagues about it. Until next time, this is Dr. Chet Zelasko saying health is a choice. Choose wisely today and every day.
