Are You An Individual?


The individuality of training is too often neglected, especially with so many runners running in groups and as part of running clubs. Both research and empirical evidence shows that there is a large inter-individual response to training, both in the magnitude of response and in the time frame for developing and retaining training effects.

What may work for one runner may not work for another. Not all runners who are capable of the same performance have the same work capacity. Some runners may respond better to high volume and low intensity while some may respond better to low volume and high intensity. Some need more recovery days between hard workouts than others. It’s important to know your training needs or, if you’re a coach or trainer, the needs of those you coach, and to individualize the training, even when in a group setting.

Training should also be individualized based on workout stress in addition to the strengths and weaknesses of each runner. For example, since the time under stress is what matters, not the actual distance, base workouts on time. If Jack and Jill do a 5-mile tempo run at lactate threshold pace to fetch a pail of water, and Jack runs 7:30 per mile pace and Jill runs 6:30 per mile pace, Jack has a more difficult workout because it’s going to take him 5 minutes longer to run 5 miles at threshold pace (and Jill will get all the water).

The Main Thing is to Keep the Main Thing the Main Thing


When I was in high school, I attended a track camp. Sort of like band camp, but we ran instead of played instruments. The name of the camp was The Mighty Burner Speed Camp. It was a pretty unique camp, not just because of its name, which might sound intimidating to some, but because of the four camp coaches. They were the members of the United States’ 1,600-meter relay team that competed at the 1968 Olympics in Mexico City. The four athletes who each ran a 400-meter leg of the relay were the fastest 400-meter runners of their generation—Vince Mathews, Ron Freeman, Larry James, and Lee Evans. Together at the Olympics, they won the gold medal in the 1,600-meter relay and set the world record of 2 minutes and 56.16 seconds, which stood for twenty years.

A man of words as well as fast legs, Larry James had a saying for us impressionable high school runners at his camp which, I found out years later, he borrowed from psychologist and author Stephen Covey: “The main thing is to keep the main thing the main thing.”

“What’s the main thing?” he asked us, as we collected as a group on the track. “The main thing is to keep the main thing the main thing,” we responded in unison.

“What’s the main thing?”

“The main thing is to keep the main thing the main thing.”

“What’s the main thing?”

“The main thing is to keep the main thing the main thing.”

Running directs your efforts, helping you to keep the main thing the main thing. There’s nothing like a long run to put the issues in our lives into perspective. We worry about things that don’t happen; we waste our time on things that don’t matter; we follow paths that lead to dead ends. Running puts us on the right path. It directs us toward a life of meaning. And it helps us get more done.

You’re a Failure… And So Am I


I’ve been talking to a talented runner where I live in San Diego for a couple of years about working with me as her running coach. She says she wants to do it, but she waffles back and forth about going through with it. Part of all her waffling is financial; she can’t afford it. But even when I offer to coach her pro bono because she’s got so much potential, she still waffles and makes a lot of excuses—her busy schedule, her young kids, needing flexibility with her training rather than a set plan, and so on. I finally asked her what all the waffling is about. “I’m afraid to fail,” she conceded.

Although we perceive that external obstacles prevent us from accomplishing things, it’s often the obstacles that lie within us that prevent us from meeting our potential. We let our fears, thoughts, and emotions control our actions. Many of us stop short of pursuing our dreams or following through with something because we’re afraid of failing. With greater success comes greater expectations, and then what if we’re not good enough to meet those expectations? It’s become too easy in our society to be complacent and maintain the status quo. And why not be complacent? Our society rewards mediocrity instead of challenging and inspiring people to be better. ‘No Child Left Behind’ has become ‘Everyone is a Winner.’

People are always impressed when they find out how many books I’ve written, how many awards I’ve won, and how many places around the world I travel for free to speak. What people don’t know is that for every book contract I have received from a publisher, there have been many other publishers who have rejected my proposal. For every award I’ve won, there have been many others I did not. And for every event I speak at, there are many others for which I applied but did not get selected. The truth is, I have failed many more times than I have succeeded. 

I’ve always been drawn to people with talent, which is perhaps why I continue to try to persuade that runner in San Diego to let me help her, but I’m even more drawn to talented people who are willing to completely commit to do whatever it takes to accomplish what they want to accomplish, however real the risk of failure may be. While there may be a chance of failing, people take risks because the chance of failing makes success taste even sweeter.

So take a few risks. But don’t take stupid risks. Educate yourself about what you’re trying to accomplish and take calculated, thoughtful risks. And surround yourself with people who will give you the strength and momentum to help see those risks through. If you want something you’ve never had, you must do something you’ve never done.

6 Lessons From Physiology and How They Make You a Better Runner


When done correctly, it is a scientific endeavor to maximize running performance. Unfortunately, nearly all scientists spend their careers in academia without venturing out into the arena that got many of them interested in physiology in the first place—competitive sport. As a result, few scientists are coaches. The opposite is also true—few coaches are scientists. Being both, I have learned that each can learn from the other, as my experience has given me a unique view of the sport and of the training process. Here are 6 lessons I have learned from physiology and how they can make you a faster runner. 

Lesson 1: Lactate threshold and running economy are more important than VOmax.

While VO₂max (the maximum volume of oxygen your muscles can consume per minute) has received most of the attention among runners and coaches, a high VO₂max alone is not enough to be a good runner; it simply gives you access into the club, since a runner cannot be good without a high VO₂max. I have tested many athletes in the laboratory with an elite-level VO₂max, but few of them were capable of running at the elite or even sub-elite level because they did not have a high lactate threshold or were not very economical. Running economy is the volume of oxygen consumed at submaximal speeds; the less oxygen you use to run at a given pace, the better.   

For longer races (half marathon and marathon), your running economy and the speed (pace) at lactate threshold are the most important factors. For shorter races (1,500 meters/mile, 5K, 10K), the speed at VO₂max is the most important factor. So that is what you have to train.   

Lesson 2: There are different muscle fiber types.

Humans have 3 types of muscle fibers, with gradations between them: slow-twitch, fast-twitch A, and fast-twitch B. The exact percentage of each that you have in your muscles is genetically determined and dictates your strengths and weaknesses as a runner. Skew your training to your strengths determined by your dominant muscle fiber type.

Lesson 3: A larger, stronger heart can pump more blood and oxygen to your muscles.

Your left ventricle is responsible for pumping blood to every inch of your body except your lungs. Your maximum stroke volume (the maximum volume of blood your heart pumps each beat) and your maximum cardiac output (the maximum volume of blood your heart pumps each minute) dictates your body’s ability to deliver oxygen to your muscles and determines your running performance. The bigger your left ventricle, the more blood it can hold; the more blood it can hold, the more blood it can pump with each beat. Make a bigger heart, and you deliver more oxygen to your muscles.  

Lesson 4: Metabolism is tightly regulated by enzymes and oxygen.

Enzymes are biological catalysts that speed up chemical reactions. The faster chemical reactions occur, the faster you produce energy (ATP) for muscle contraction. Make more enzymes involved in the aerobic and anaerobic metabolic pathways, and you make ATP faster, which enables you to run faster.

Metabolism is also regulated by the availability of oxygen, which determines the metabolic pathway used. If there is adequate oxygen to meet the muscle’s needs, your muscles will rely on aerobic metabolism. Conversely, if there is not adequate oxygen to meet your muscle’s needs, your muscles will rely on anaerobic metabolism, which causes the development of acidosis, causing you to fatigue and slow down.

Lesson 5: Carbohydrates are extremely important.

People think carbs are bad. If you are one of those people, stop it. Research since the 1960s has shown that endurance performance is strongly influenced by the amount of stored muscle glycogen, with intense endurance exercise decreasing muscle glycogen content. Carbohydrates are so important that ingesting them during prolonged exercise delays fatigue. That muscles prefer carbohydrate as a fuel is so fundamental to exercise metabolism, when your carbohydrate fuel tank gets very low, your liver makes glucose from amino acids and lactate to assuage the threat of a low carb fuel tank. (That’s why a ketogenic diet doesn’t really keep you in ketosis—because your liver is smarter than you and will break down protein into amino acids to make more glucose to assuage the threat presented by not eating carbs.) You need carbs to run fast.

Lesson 6: Most female distance runners get better the longer the race.

Estrogen shifts metabolism to a greater reliance on fat and less on carbohydrate when running at the same pace as a man. The longer the race, the more important this shift in metabolism becomes, since the conservation of carbohydrate is very important given that we have only a limited store of it. The faster the pace you can run while still using mostly fat, the better long-distance runner you will be. Most women, therefore, get better the longer the race. The performance difference between men and women is much smaller for ultramarathons than it is for races shorter than a marathon because the longer the race, fuel use starts to outweigh the importance of cardiac performance and oxygen transport in the blood, characteristics that favor men. Because of women’s estrogen-induced predisposition toward endurance, women should embrace aerobic training and run a lot to maximize their running performance. (Get my book, Running for Women, for a lot more detail, including how to train around the menstrual cycle, pregnancy, and menopause.) 

14-Minute Workouts


Excerpted from 14-Minute Metabolic Workouts ©Jason R. Karp

Beginning in the seventh grade, I became fascinated with time—specifically how fast it goes and how each year seems to go by faster than the previous year. When I once shared my perception of time with my 90-year-old grandmother, she said, “Just wait until you’re 80.” I’m still far from 80, so I can only imagine how fast time will go by then. It likely will go by in no time at all. Even now, each second that comes is gone just as fast, leaving us with only future and past. The advice to “stay present in the moment” becomes impossible.

I’ve spent much of the last 30 years appreciating the impact that short workouts can have and creating workouts that can make people extremely fit in a short time. 

Why 14 minutes? Because it’s precise. You pay attention. You focus on the effort because you know the time will be gone as fast as it arrived. Enjoy the time.

VO2max Pyramid

  Duration RPE* Intensity
Rep #1 1:00 9 >95% max HR
Recovery 1:30 2-3
Rep #2 1:30 9 >95% max HR
Recovery 1:30 2-3
Rep #3 3:00 9 >95% max HR
Recovery 1:30 2-3
Rep #4 1:30 9 >95% max HR
Recovery 1:30 2-3
Rep #5 1:00 9 >95% max HR
Total Time 14:00

*RPE = Rating of Perceived Exertion on a scale of 1 (easy) to 10 (maximum effort)

Treadmill Triple 3 Hills
3 Reps, 3 Minutes, 3% Grade

  Duration Grade RPE* Intensity
Rep #1 3:00 3% 9 >90% max HR
Recovery 2:00 0% 2-3
Rep #2 3:00 3% 9 >90% max HR
Recovery 2:00 0% 2-3
Rep #3 3:00 3% 9 >90% max HR
Total Time 13:00  

Use the same workout speed for each rep and the same recovery speed for each recovery interval. For the reps, choose a speed that is challenging. For the recovery intervals, decrease the speed to a slow jog that enables you to recover before the next rep. *RPE = Rating of Perceived Exertion on a scale of 1 (easy) to 10 (maximum effort)

Sprint Pyramid

  Duration RPE* Intensity
Rep #1 :10 9 Fast
Recovery :20 2-3
Rep #2 :20 9 Fast
Recovery :40 2-3
Rep #3 :30 9 Fast
Recovery 1:00 2-3
Rep #4 :40 9 Fast
Recovery 1:20 2-3
Rep #5 :50 9 Fast
Recovery 1:40 2-3
Rep #6 :40 9 Fast
Recovery 1:20 2-3
Rep #7 :30 9 Fast
Recovery 1:00 2-3
Rep #8 :20 9 Fast
Recovery :40 2-3
Rep #9 :10 9 Fast
Total Time 12:10

*RPE = Rating of Perceived Exertion on a scale of 1 (easy) to 10 (maximum effort)

True Tabata

  Duration RPE* Intensity
Rep #1 :20 10 Nearly all-out
Recovery :10 2
Rep #2 :20 10 Nearly all-out
Recovery :10 2
Rep #3 :20 10 Nearly all-out
Recovery :10 2
Rep #4 :20 10 Nearly all-out
Recovery :10 2
Rep #5 :20 10 Nearly all-out
Recovery :10 2
Rep #6 :20 10 Nearly all-out
Recovery :10 2
Rep #7 :20 10 Nearly all-out
Recovery :10 2
Rep #8 :20 10 Nearly all-out
Total Time 3:50

Do this workout on a stationary bike and sprint nearly as fast as you can for each 20-second rep. In Tabata’s original research study, subjects cycled at 170% VO2max, which was determined from previous VO2max tests in their laboratory, and they did the workout five times per week for six weeks. Don’t try that at home! *RPE = Rating of Perceived Exertion on a scale of 1 (easy) to 10 (maximum effort)

Muscular Endurance Upper Body Drop Sets

Exercise Sets Reps Intensity
(% 1 rep max or RPE)
Chest Press 3 10 80-85 / 75-80 / 70-75% :10
Chin-Ups 3 10 80-85 / 75-80 / 70-75% :10
Seated Cable Row 3 10 80-85 / 75-80 / 70-75% :10
Triceps Pressdown 3 10 80-85 / 75-80 / 70-75% :10

Decrease the amount of weight after the first set by 5 to 10 pounds and immediately do the next set of 10 reps. Then drop the weight again by another 5 to 10 pounds and immediately do the third set. A 10-second recovery between sets is built into the workout to give you enough time to decrease the amount of weight.

Sprint/Body Weight Circuit

Exercise Duration/Reps
Sprint :30
Squat Jumps 10-15
Push-Ups 10-15
Pike Crunches 10-15
Sprint :30
Squat Side Steps 10-15 each side
Superman 10-15
V-Sit 10-15
Sprint :30
Mountain Climbers 10-15 each leg
Triceps Dips 10-15
Russian Twists 10-15

This circuit sequences sprint running with a lower-body exercise, upper-body exercise, and core exercise for a total-body workout. Go immediately from one exercise to the next. Do the circuit once or twice with 2 minutes rest between circuits. If you do this workout in a gym, you can substitute sprint cycling for sprint running. Make the sprint fast and challenging, but not all out.

Upper Body Strength Pyramid

Exercise Sets Reps Intensity
(% 1 rep max or RPE)
Chest Press 1 / 2 / 3 10 / 8 / 6 75-80 / 80-85 / 85-90% 1:00
Seated Cable Row 1 / 2 / 3 10 / 8 / 6 75-80 / 80-85 / 85-90% 1:00
Biceps Preacher Curls 1 / 2 / 3 10 / 8 / 6 75-80 / 80-85 / 85-90% 1:00
Triceps Pressdown 1 / 2 / 3 10 / 8 / 6 75-80 / 80-85 / 85-90% 1:00

Increase the amount of weight by 5 to 10 pounds as you decrease the number of reps in each set.

Want more great workouts? Pick up a copy of 14-Minute Metabolic Workouts 

Nice Legs


A number of years ago, I was talking to one of the members of a local gym in which I was working as a personal trainer as she rode a stationary bike alongside her workout buddies. As I explained how she and her friends could get more out of their workouts, I sensed that she wasn’t listening. Maybe she didn’t care for the advice of a young, scrawny-looking runner in sweats. Maybe she was just focused on her workout. A few days later, I saw her again as I was about to go for a run. Seeing me for the first time in my running shorts, she enthusiastically asked, “How can I get legs like yours?” Smiling, I joked, “So, you want me for my body rather than for my mind?” Everyone wants nice legs.

Try this workout from my book, 14-Minute Metabolic Workouts to get nice legs, which will take you less than 14 minutes. Get the book for more great workouts. 

Dumbbell Deadlift: 3 sets, 5-8 reps @ 80-85% 1-rep max w/2:00 rest between sets

Dumbbell Side Lunges: 3 sets, 5-8 reps @ 80-85% 1-rep max w/2:00 rest between sets

Dumbbell Plié Squats: 3 sets, 5-8 reps @ 80-85% 1-rep max w/2:00 rest between sets

Dumbbell Deadlift

Hold a dumbbell in each hand by your sides at arm’s length and stand with your feet shoulder width apart. Keeping your back and legs straight, bend over at the waist to lower the dumbbells until your back is parallel to the floor. As you bend over, you should feel a stretch in your hamstrings. Keeping your back and legs straight, stand upright to return to the starting position and repeat for the prescribed number of reps.



Dumbbell Side Lunges

Hold a dumbbell in each hand in front of you, with your palms facing each other, and stand with your feet shoulder-width apart. Take a big lateral step out to your left side and lower yourself into a squat, keeping your right leg straight. Push back up with your left leg to return to the starting position and repeat for the prescribed number of reps before switching to the right leg.



Dumbbell Plié Squats

Stand with feet slightly greater than shoulder-width apart and toes turned out about 45 degrees. Hold a dumbbell vertically with both hands between your legs. Keeping your back straight, squat down until your thighs are parallel to the floor. Push through your feet to stand up to return to the starting position and repeat for the prescribed number of reps.



Training by Time

Beginning in the seventh grade, I became fascinated with time, specifically how fast it moves and how each year seems to go faster than the previous year. Time spent running is also interesting—the second half of a run always seems to go faster than the first, and some runs seem to fly by while others seem to drag on. This changing perception of time may be partly explained by its relationship to effort, as Dr. George Sheehan once noted: “The faster we run, the longer it takes.”

As runners, we tend to think a lot about mileage. Indeed, it’s the number of miles we run each week that often defines our status as runners. The more miles we run, the more we’re validated. Other runners will ask you how much mileage you run and make judgments about you based on the answer you give.

The amount of time spent running, however, is more important than the number of miles—since it’s the duration of effort that represents the amount of training stress. A faster runner will cover the same amount of distance in less time than a slower runner or, to put it another way, will cover more miles in the same amount of time. For example, a runner who averages 7-minute mile pace for 40 miles per week is running the same amount of time as a runner who averages 10-minute mile pace for 28 miles per week (280 minutes per week), and therefore is experiencing the same amount of stress. And that’s what matters—the stress. If a slower runner tries to run as much as a faster runner, the extra time it will take increases the amount of stress and therefore puts the slower runner at a greater risk for injury.

The same is true when you’re doing long runs in preparation for a marathon—don’t worry about running 20 miles or 21 miles or 22 miles. Focus on lengthening the time. However, since races are over a specific distance rather than over a specific time, a faster runner doing a 22-mile run is getting more specific training toward a 26.2-mile race than a slower runner running 17 miles in the same time. Since a marathon is 26.2 miles for everyone, the race is more stressful for a 4-hour marathoner than it is for a 2:10 marathoner (assuming that both are running at the same percentage of maximum effort). Therefore, a 4-hour marathoner needs to get used to running for a longer time than does a 2:10 marathoner. But this need to run for more time must be balanced by the amount of recovery time needed. In other words, if you focus solely on the number of miles, the runs can get so long that the recovery time you’ll need will increase dramatically and will begin to negatively affect your next week of training.

Focusing on time rather than on distance is a better method for equating the amount of stress between runners of different abilities. Your body has no comprehension of what a mile is; it only knows how hard it’s working and how long it’s working. Effort over time. The duration of effort is one of the key factors that arouses the biological signals that induce physiological adaptations that will ultimately lead to improvements in your running performance.

This concept of training by time should also be applied to individual workouts. This is the biggest flaw of group training, during which everyone in the group runs the same workout. A slower runner should not attempt the same number of reps of the same distance in an interval workout as a faster runner; otherwise he or she will experience more stress because he or she will be spending more time running at the same relative intensity. For example, an 18:00 5K runner who runs 5 x 1,000 meters at 5K race pace will experience more stress than a 15:30 5K runner who does the same workout. The corresponding times of the two workouts would be 3:37 per 1,000 meters (5:48 mile pace) and 3:07 per 1,000 meters (5:00 mile pace), respectively. For this workout, the slower runner would be running 30 seconds (or 16 percent) longer at the same relative intensity as the faster runner. To make these two workouts more comparable, and therefore to equate the stress experienced by both runners, the 18:00 5K runner should modify the workout by running 850 meters (which would take 3:04) rather than running 1,000 meters. If 850 meters is too awkward of a distance to determine, you can run either 800 or 900 meters. The point is to make the two workouts more comparable by shortening the distance for the slower runner (or, conversely, by increasing the distance for the faster runner).

There are a couple of other ways to make these two workouts comparable—the 18:00 5K runner can decrease the number of reps or increase the recovery interval. For example, if both runners run the same distance (1,000 meters) and the 15:30 5K runner does five reps (for a total running time of 15:35 at 5K race pace), the 18:00 5K runner should do four reps (for a total running time of 14:28 at 5K race pace). Alternatively, if the 15:30 5K runner takes 3 minutes of recovery between reps, giving a work-to-rest ratio of 1-to-1, the 18:00 5K runner should take 3½ minutes of recovery to make the ratio the same. While manipulating the number of reps or the recovery interval will make the two workouts more comparable between runners, the best way to equate the stress between these two workouts is the initial way described—shorten the length of the reps, since the time spent running at a specific intensity represents the greatest aspect of the training stress. If the 18:00 5K runner runs 1,000-meter reps like the 15:30 5K runner, but takes more recovery to keep the work-to-rest ratio the same, it’s still a harder workout for the 18:00 runner.

In an effort to equate the stress of workouts between runners of different abilities, I have developed a hierarchy of strategies:

1. Decrease the duration of each rep for slower runners (or increase the duration of each rep for faster runners) to make the duration of each rep the same between runners.

2. Decrease the number of reps for slower runners (or increase the number of reps for faster runners) to make the total time spent running at a specific intensity the same.

3. Increase the duration of the recovery interval for slower runners (or decrease the duration of the recovery interval for faster runners) to make the work-to-rest ratio the same.

If you stop training by mileage and start training by time, not only will you do the amount of training that’s right for you, you may even save some valuable time.


Gerry Lindgren, Running, and a Lesson About Life


“I couldn’t run a few steps without falling over,” Gerry said as we ran through Honolulu’s Ala Moana Park. Little did I know that running with 71-year-old Gerry Lindgren during my short trip to Hawaii to teach the REVO₂LUTION RUNNING™ certification course was going to be so profound of an experience.

Gerry began running as a high school sophomore in Washington state “to get out of the house.” His father, he told me during our run, was an alcoholic and his mother was an enabler.

“I was the slowest runner on the cross country team,” he said. One day, he sprinted out in front of everyone during an interval workout on the track. Halfway through the lap, he ran out of gas and everyone passed him. “I always saw myself as a wimp. I have been a wimp my whole life,” he says.

After that workout, his coach took him aside and told him, “You’ll never beat these guys when they get in shape, but you can help the team by taking the early lead, because they just ran their fastest workout by chasing you.”

And so Gerry Lindgren took the pace out fast in every race so he could help his team.

If you follow track and field, you know who Gerry Lindgren is, and you know how this story ends. This uncoordinated teenage kid who couldn’t run a few steps without falling and who saw himself as a wimp went on to run a 4:01 mile, 8:40 two-mile, and 13:44 5K while in high school, set American records, ran in the Olympics, and became one of the best runners in the world. But what you probably don’t know is how and why he got there.

“When I had run the fastest time in the country for two miles, I said to myself, “Now how could a wimp be the fastest in the country?” It’s remarkable how something as simple as running fast can quickly improve your self-esteem.

Given my interest in how running enables us to deal with discomfort that I wrote about in The Inner Runner, I asked Gerry how he was able to take the pace out so fast and hold on, where that ability to deal with discomfort came from.

“I was able to do it when I knew it was for the team. When I ran for myself, that ability was never there. When I ran to help others, it was always there.”

Gerry Lindgren’s words were so profound that they nearly stopped me in my tracks in Ala Moana Park.

“That’s a life lesson, Gerry,” I said to him. “You could take that message all over the world.”

I learned a lot about Gerry Lindgren (and about life) while running with him in Hawaii. He told me his favorite runner to race was Ron Clarke from Australia because Ron always ran an honest race, running fast from the start. (“Because Ron ran so fast early in the race, he didn’t have a great kick, so he could be beaten if the other runners could stay with him early,” Gerry said.) But what I learned the most is that we can accomplish a lot more when we get out of our own way and serve others instead of serving ourselves. Gerry truly believes that, and believes it was the reason for his success. I wish I had met Gerry Lindgren and knew his story before writing The Inner Runner because I would have included his story in the book.

I asked him how many people knew his story. “Not that many,” he said. Well, I hope they do now.    

Follow Gerry Lindgren on Facebook (@gerrythejogger), and if you’re ever in Honolulu, go for a run with him and ask him to tell you a story. 

How to Do Interval Workouts Correctly


Once the training secret of the world’s best runners, interval training is now done by everyone, from competitive athletes to grandma next door.

Emil Zatopek of the former Czechoslovakia, who won the 10K at the 1948 Olympics and 5K, 10K, and marathon at the 1952 Olympics, was the first athlete to popularize interval training. However, it wasn’t until the 1960s that famous Swedish physiologist Per-Olaf Åstrand discovered that breaking up a set amount of work into smaller segments enables individuals to perform a greater volume of work at a high intensity. Sounds obvious, but Åstrand’s simple observation is the basis for interval training. For example, you can run 5 x 1,000 meters faster than you can run 5,000 meters; you can run 10 x 500 meters faster than 5 x 1,000 meters; and you can run 20 x 250 meters faster than 10 x 500 meters. However, this is where a lot of coaches and runners make mistakes. We’ll get to that in a minute.

When interval training was first studied in the 1930s by coach Waldemar Gerschler and physiologist Hans Reindell of Germany’s Freiburg University, they focused their attention on its cardiovascular aspects and believed that the stimulus for cardiovascular improvement occurs during the recovery intervals between work periods rather than during the periods of activity, as the heart rate decreases from an elevated value. Thus, the emphasis of the workout was placed on the recovery interval, prompting Gerschler and Reindell to call it an “interval workout” or “interval training.” Gerschler and Reindell’s original interval training method consisted of running periods ranging from 30 to 70 seconds at an intensity that elevated the heart rate to 170 to 180 beats per minute, followed by sufficient recovery to allow the heart rate to decrease to 120 beats per minute, signifying the readiness to perform the next work period.

During the recovery interval, the heart rate declines rapidly, but there is a lot of blood returning to the heart from the muscles, which leaves more time for the left ventricle to fill with a lot of blood, and subsequently eject a lot of blood with each beat (called the stroke volume). The increase in stroke volume places an overload on the heart, which makes the heart stronger. Since stroke volume peaks during the recovery interval, and because there are many recovery intervals during an interval workout, stroke volume peaks many times, providing a stimulus for improving maximum stroke volume and thus the capacity of the oxygen transport system. Pretty neat, huh?

Also during the recovery intervals, a significant portion of the muscular store of quick energy—creatine phosphate (CP)—that was depleted during the preceding work period is replenished via the aerobic system. During each work period that follows a recovery period, the replenished CP will again be available as an energy source.

Interval training manipulates four variables: time (or distance) of each work period, intensity of each work period, time of each recovery period, and number of repetitions. With so many possible combinations of these four variables, the potential to vary training sessions is nearly unlimited. Possibly the greatest use of interval training lies in its ability to target individual energy systems and physiological variables, improving specific aspects of your fitness level.

Back to the mistakes that coaches and runners make with interval training, and how to do interval workouts correctly.

(1) Know the purpose of the workout and match the pace to the purpose. If the purpose is to improve VO₂max, then run at your VO₂max pace, which you can determine from a recent race, from heart rate, and eventually by feel as you gain experience with these workouts. Do not run workouts at arbitrary paces, which is what most runners do. Always match the pace of the workout to its purpose.

(2) Run only as fast as you need to meet the purpose of the workout. If the purpose of the workout is to improve VO₂max, then run at your VO₂max pace, no faster. Make the workout harder by doing more volume at the right pace (or decrease the time of the recovery interval between reps) rather than run faster than the right pace. Just because you can run faster doesn’t mean you should. To stress the system, run at the upper limit of that system; there is no reason to run faster because that confers no greater benefit.

(3) Design interval workouts correctly, with an understanding of Åstrand’s research: By breaking up a period of work into periods of work and rest, you can perform a greater volume of work at a high intensity. For example, if you run 10 x 400 meters at 5K race pace, that workout doesn’t adhere to the purpose of an interval workout. It’s actually too easy of a workout because 10 x 400 meters is only 4,000 meters, which is less than the 5,000 meters that you could have held the pace for without any recovery intervals. So if you’re going to run 400-meter reps at 5K race pace, you need to run enough reps such that the total distance of the workout exceeds 5,000 meters, which is at least 13 reps. And since the reps are only 400 meters in length, which is only 8% of the distance that you can hold the pace, you should do many more than 13 reps at that pace to stress the system.

(4) Don’t run (or at least limit how much you run) at 5K, 10K, or half marathon race pace, unless you are specifically trying to practice running at race pace. These race distances don’t correspond to any specific physiological factor that influences performance. For example, 5K pace is too slow to achieve the benefits of a VO₂max workout and too fast to achieve the benefits of a lactate threshold workout. It’s much better to design workouts that specifically target the physiological variables that dictate your race performance. If you improve lactate threshold, VO₂max, running economy, anaerobic capacity, etc., your races will get better even without running at race pace because you will have improved the specific factors of your physiology that make you a better runner.    

Aerobic Power (Cardiovascular) Intervals

One of the best methods to improve the capacity of your cardiovascular system—specifically, your heart’s ability to pump blood and oxygen to the active muscles—is interval training using work periods lasting 3 to 5 minutes and recovery periods equal to or slightly less than the time of the work periods. The cardiovascular adaptations associated with interval training, including hypertrophy of the left ventricle and a greater maximum stroke volume and cardiac output, increase your VO₂max (the maximum volume of oxygen muscles consume per minute), raising your aerobic ceiling. Since VO₂max is achieved when maximum stroke volume and heart rate are reached, the work periods should be performed at an intensity that elicits maximum heart rate during each work period. This type of interval workout, which is very demanding, is one of the best workouts you can do to improve cardiovascular conditioning.

Anaerobic Capacity (Speed Endurance) Intervals

Anaerobic capacity refers to the ability to regenerate energy (ATP) through glycolysis. Work periods lasting 30 seconds to 2 minutes target improvements in anaerobic capacity by using anaerobic glycolysis as the predominant energy system. These short, intense work periods with recovery intervals 2 to 4 times as long as the work periods increase muscle glycolytic enzyme activity so that glycolysis can regenerate ATP more quickly for muscle contraction and improve the ability to buffer the muscle acidosis that occurs when there is a large dependence on oxygen-independent (anaerobic) metabolism.

Anaerobic Power (Speed) Intervals

Anaerobic power refers to the ability to regenerate ATP through the phosphagen system. Work periods lasting 5 to 15 seconds target improvements in anaerobic power by using the phosphagen system as the predominant energy system. These very short, very fast sprints with 3- to 5-minute recovery intervals that allow for complete replenishment of creatine phosphate in the muscles increase fast-twitch muscle fiber activation and the activity of creatine kinase, the enzyme responsible for catalyzing the chemical reaction that breaks down creatine phosphate.

Sample Interval Workouts
Make sure you warm-up and cool-down before and after each workout.

Aerobic (Cardiovascular) Intervals (Aerobic Power):

• 5 x 3 minutes @ VO₂max pace (95-100% max HR) with 2½-3 minutes jog recovery
• 3 x 4 minutes @ VO₂max pace (95-100% max HR) with 3½-4 minutes jog recovery
• 3, 4, 5, 4, 3 minutes @ VO₂max pace (95-100% max HR) with 2½-3 minutes jog recovery
VO₂max pace = 3K (2-mile) race pace or slightly faster for good runners; about 1½-mile race pace for recreational runners 

Anaerobic Capacity (Glycolytic) Intervals (Speed Endurance):

• 4 to 8 x 30 seconds at 95% all-out with 2 minutes jog recovery
• 4 to 8 x 60 seconds at 90% all-out with 3 minutes jog recovery
• 2 to 3 sets of 30, 60, 90 seconds at 90-95% all-out with 2 to 3 minutes jog recovery & 5 minutes rest between sets
Anaerobic Capacity pace = Mile race pace or slightly faster for good runners; about ½-mile race pace for recreational runners  

Anaerobic Power (Phosphagen System) Intervals (Speed/Power):

• 2 sets of 8 x 5 seconds all-out with 3 minutes passive rest & 5 minutes rest between sets
• 5 x 10 seconds all-out with 3-4 minutes passive rest
• 2 to 3 sets of 15, 10, 5 seconds all-out with 3 minutes passive rest & 10 minutes rest between sets

If you like this, you’ll LOVE the REVO₂LUTION RUNNING™ certification, where we go very deep into how to train correctly to get the best results. Try it out at

How Should I Breathe When I Run?


“How should I breathe when I run?” 

I get asked this question all the time. We often take breathing for granted.

Many runners are told to “belly breathe,” to breathe from their diaphragm and take deeper breaths to take in more oxygen. However, the main stimulus to breathe, especially at sea-level, is to exhale carbon dioxide, as the partial pressure of CO2 rises in the blood from metabolism. At sea-level, your blood is nearly 100% saturated with oxygen, even while running a race, so it’s fruitless to take deeper breaths since what matters is how much oxygen is transported in your blood, not how much oxygen is in your lungs. The best distance runners in the world are small people, and so they have small lungs. When I measured total lung capacity of runners in the lab, I found that the smaller runners had smaller lung volumes, even though they were better runners. There is no relationship between your lung volume and how fast you run a 5K or marathon.

Since your diaphragm and other breathing muscles also use oxygen, the muscle contractions associated with deeper breaths can potentially “steal” some of the oxygen your leg muscles need to run. When you travel (or live) at higher altitude, you breathe more to compensate for the decreased partial pressure of oxygen in the environmental air. (Oxygen molecules travel from areas of higher pressure to areas of lower pressure, so the greater the difference in oxygen pressure between the environmental air and the air in our lungs, the greater the driving force for oxygen to travel from the environment into our lungs. The higher up in altitude you go, the less the pressure difference between the environmental air and the air in our lungs.)

While taking deeper breaths won’t help your running, coordinating your breathing to your stride rate can. Most animals, like the cheetah, coordinate their breathing patterns to their stride rates because of how the movement of their forelimbs assists the movement of their chest cavity. And so four-legged animals take a 1-to-1 step-to-breath ratio: For every step, they take one breath.

This coordination of breathing to stride rate, which is called “entrainment,” also happens in humans, although it is not as tightly coupled since humans have a greater anatomical separation between the movement of their legs and chest cavity. In humans, the entrainment of breathing to stride rate is linked to running experience, with more fit and experienced runners exhibiting greater entrainment. For my doctoral dissertation, I measured this entrainment of breathing and stride rate, and found that human runners take 3 or 4 steps per breath (inhalation + exhalation) when running at easy to moderate paces, and two steps per breath when running fast. With many miles of training, runners may learn how to most effectively ventilate their lungs and minimize the metabolic cost of breathing, which can improve running economy (the amount of oxygen you use to maintain a given submaximal pace).

Although the entrainment of breathing to stride rate seems to happen naturally with training, you can voluntarily coordinate the two rhythms. When you run, begin to exhale when either your right foot or left foot lands on the ground, and go through a complete breath (exhalation + inhalation) every 3 to 4 steps, always exhaling when your foot lands on the ground. When you run fast, try to take two steps per breath. 

Do NOT follow this link or you will be banned from the site!
© Copyright 2019