CTL. Chronic Training Load has rapidly gained in popularity among endurance athletes, but how well understood is this complex metric? Today we discuss the benefits of CTL, as well as the issues that can arise if too much stock is placed in this one number.  

 

CTL can tell you the general level you’re at, and more importantly, it can indicate trends in your training and help direct your training plan. But is this little acronym quickly replacing FTP as the metric of reference? Indeed, many people seem to think of it as an indication of how strong they are. But should they? Are there any dangers to doing so? As always, we start by taking a step back and defining how it is calculated and what assumptions and estimates it is based on. 

 

Today, Trevor and I discuss the good, the bad, and the ugly of CTL. Ultimately, we want to try and answer as many of the questions we’ve received about this metric as possible, and help illustrate why a focus on training principles, rather than any single number, is much more effective for creating adaptations and seeing gains. 

 

As we always do on our summary episodes, we hear from a world-class group of coaches, scientists, and athletes, including Tim Cusick, Larry Warbasse, Joe Friel, Dr. Stephen Seiler, Dr. Iñigo San Millan, Kendra Wenzel, and others. 


Let's make you fast!

178: The Good, the Bad, and the Ugly of Chronic Training Load (CTL)

Bike fit was once purely a quote-unquote “philosophy.” In the old days, you may have experienced getting a so-called fit by a guy at a bike shop with a plumb line and a theory. Now, bike fit is a full-fledged science—there are video cameras everywhere, 3D modeling, and so on. That being said, it’s a science that is still influenced by philosophy—what each fitter brings to the exam and analysis that impacts his or her perspective.

Today, we’ve gathered three of the great minds in bike fit to discuss this complex and extremely important aspect of cycling. When we sat down to discuss the topic, to no one’s surprise, they spoke for hours, so we’ve decided to split this conversation into two parts.

Today, we start with a discussion about the philosophy of fit, and how science fits into that philosophy. In part 2, we’ll discuss the practical implications of bike fit, from the debate over aerodynamics versus power, to our guest’s feelings about technology versus experience and intuition.

Our guests’ immense experience and influence on the world of bike fit cannot possibly be captured in a single sentence, but that’s what I’ll try to do.

Dr. Andy Pruitt is the director of sports medicine here at Fast Talk, and one of the pioneers of the study of cycling biomechanics. Our next guest has appeared on Fast Talk many times before, and he also continues to host his own podcast, “Cycling in Alignment.” Of course, I speak of Colby Pearce. Finally, making his Fast Talk debut is Todd Carver, co-founder of Retül and the head of human performance at Specialized, which now owns the Retül fit technology.

What do each of our guests have to say about his fit philosophy? What’s involved in a fit? What's the goal of a fit? Stay tuned.

Let's get you fit… and make you fast!

Fast Talk

187: Bike Fit Philosophy, with Dr. Andy Pruitt, Colby Pearce, and Todd Carver

188: Nerd Lab: FTP, VO2max, and Sprints within LSD

In the beginning, a bike fit would include a guy at a bike shop with a plumb line and a theory. Now, bike fit is a full-fledged science with video cameras, 3D models, and a greater understanding of human anatomy and physiology as it pertains to cycling.

In part 2 of our bike fit discussion, we’ll explore the practical implications of bike fit, from the debate over aerodynamics versus power, to our guest’s feelings about technology versus experience and intuition, and many other subjects, generally in the realm of "methodology."

Once again we're joined by three of the great minds in bike fit.

Dr. Andy Pruitt is the director of sports medicine here at Fast Talk, and one of the pioneers of the study of cycling biomechanics. Our next guest has appeared on Fast Talk many times before, and he also continues to host his own podcast, “Cycling in Alignment.” Of course, I speak of Colby Pearce. Finally, making his Fast Talk debut is Todd Carver, co-founder of Retül and the head of human performance at Specialized, which now owns the Retül fit technology.

Fast Talk 

189: Bike Fit Methodology, with Dr. Andy Pruitt, Colby Pearce, and Todd Carver Part 2

There are many ways to measure intensity. This is an episode about the one that is often forgotten: RPE.

Perceived exertion is a standardized way to classify a subjective feeling. We've touched upon RPE in many episodes, often referring to the fact that top pros all know "the feel."

Today, we argue that the metric of feeling—perceived exertion, RPE, sensations, whatever you call it—is in many ways the most important metric. Yes, we're arguing that it is even more important than power and heart rate.

We set the stage by defining RPE. Next, we lay out our argument for why RPE may be the most important metric—whether in the training or racing context.

Then we turn our attention to ways to learn how to understand or interpret feelings to determine RPE. It's not an easy task, but there are certain steps you can take to hone your sense of, well, sense.

Finally, we discuss the best ways to use RPE, from the ability to assess where you're at to knowing what efforts of a given length "feel like" so that you can then use that to pace in races; from adjusting power and HR in training to how the sRPE scale can be used to integrate off-the-bike workouts into overall training load.

Since this is a summary episode, we pulled from previous episodes to hear from a host of the most prominent coaches, athletes, and researchers, including: Jeff Winkler, Joe Friel, Kristen Legan, Amos Brumble, Dirk Friel, Kristin Armstrong, Ned Overend, Dr. Stephen Seiler, Kate Courtney, Svein Tuft, and Julie Young.

190: Is Perceived Exertion the Most Important Metric?

This first question we’ve saved for this special occasion. Brenda Castile from Essex, Connecticut, writes:

“Thanksgiving! I love it. I love the food, I love the drinks, I love the desserts. I love being around family. All of which means I’m exposed to calories and germs, a cyclist’s worst nightmare. And, as usual, it comes just a couple of weeks before I want to be at my best for the finale of ‘cross season.

So, how can I have my cake and eat it too? How does someone who takes the sport seriously, as I do, but who also has the perspective on ‘normal’ life to know that I shouldn’t boycott a special gathering that I love for a chance at a dinky medal at ‘cross nationals this year.

Am I just playing mind games with myself? Can I splurge for a day, do my best to limit my exposure to germs and other creepy crawlies, and then get straight back on the wagon the next day, no worse for wear? How do I keep the mind games from making me feel guilty and exposed right when I want to be buckling down for a chance at amateur glory?”

Binge before or after?

This next question comes from Sid Merriman in Dover, Delaware. He writes:

“Simple question: before or after? Thanksgiving is a time for feasting and turkey trots, but do I feast first and then trot, or trot then feast?

My wife and I debate the topic of timing every year. I want to get my turkey trot in first, then binge like there’s no tomorrow—which means she’s pushing back the Thanksgiving meal until late afternoon to accommodate my schedule. She wants me to eat first, so that I get to the turkey trot later in the day to work off that ginormous plate of pecan pie—which means I'm pushing her to have the Thanksgiving meal at or before noon so I have time to digest 8,000 calories before running my brains out. Who’s right, me or my wife?”

Avoiding the Jan Ullrich effect

This question comes from Casey Hickock in Bend, Oregon. He writes:

“When I was first getting into cycling in the late 1990s, I remember watching the Tour de France on TV when Lance Armstrong and Jan Ullrich were battling. When it came to Jan, a topic of conversation that always seemed to pop up was about his weight, and how much he would put on in the off-season and how hard it would be for him to lose it the following season.

Well, I know how the man must have felt. Leaving everything else from that era aside, can you help me avoid the seemingly inevitable weight gain of winter—I slow down, the food and beer seem to get richer and more plentiful, and the weight gain speeds up. Every year it gets harder to shed the weight come spring. Surely, you’ve heard this before or even dealt with it yourself. I imagine discipline is key here… but besides that, what can I do to avoid this up and down cycle year after year?”

Food as medicine

This question comes from Brad With. He writes:

“I recently read an article by Trevor where he discusses health issues, inflammation, and sickness during his cycling training. I've raced bikes for about 18 years in Colorado. I have been plagued with frequent colds (8-10 a year), digestive issues, and Celiac disease. I have also had a bout of viral postural orthostatic tachycardia (POTS) syndrome. I also had a rare and serious pneumonia that almost took my life in 2012.

I always felt that there was possibly a major factor contributing to these problems. I am seriously considering whether it's the food I'm eating. I'm trying to find some evidence that a drastic change in diet could contribute to improving my health. Paleo is one of the avenues I would like to try. I would like to find other (anecdotal) evidence that Paleo has improved the health of others.”

191: Q&A on Thanksgiving Mind Games, Jan Ullrich Effect, and Food as Medicine

On several previous episodes of Fast Talk, we have discussed the structural and biochemical changes that take place through the process of adaptation—through training. Today we’re going to address one of the most important and interesting structural changes, something called exercise-induced cardiac remodeling.

As you train, your heart changes: This remodeling includes things like increases in chamber volume and muscle wall hypertrophy. Of course, these changes don’t happen after one set of intervals, so today we’ll discuss how long they take, and how quickly they are lost if you detrain or stop training because of injury. We’ll also explore both the performance changes and health consequences of this remodeling.

We’re excited to be joined today by two leading experts in this area of research and clinical practice, Dr. Bradley Petek and Dr. Timothy Churchill.

Dr. Petek is a cardiology fellow at Massachusetts General Hospital and one of the authors of the journal article entitled “Cardiac effects of detraining in athletes: a narrative review” that you’ll hear us refer to in the show.

And Dr. Churchill is a cardiologist at Massachusetts General Hospital and an Instructor at Harvard Medical School. He is a member of that hospital’s Cardiovascular Performance Program, where he studies cardiovascular adaptations to exercise as they apply to health, disease, and human performance.

We’ll also hear from coach Julie Young to get her sense of how this remodeling effects physiology testing.

We’ll also hear from coaches Julie Young and Jared Berg to get their understanding of how cardiac remodeling effects athletes of all abilities.

Let's make you fast!

Episode 197: Cardiac Remodeling in Endurance Athletes, with Dr. Brad Petek and Dr. Tim Churchill

Interval workouts are often tough and many athletes finish them wondering if they were effective. We discuss how to get the most from your interval workouts with Dr. Stephen Seiler.

FT267: Are Your Interval Workouts Effective?—with Dr. Stephen Seiler

Learn how to get the most from your training and fueling—and avoid the pitfalls of overtraining—with advice from a leading academic.

Fast Talk Femmes Podcast: How to Avoid Overtraining—with Dr. Trent Stellingwerff

Rob, Grant, and Trevor are back with another Potluck episode. We discuss a host of odd, interesting, and humorous training topics in this week’s show.

FT270: Structured Training Plans, Building A Base For Attacks, And Contradicting Science

We talked with Sonya Looney about how the positive psychology concepts of flow states, flourishing, and grit are essential for athletes to both perform their best and enjoy their sport.

FT287: What the Field of Positive Psychology Has to Offer to Athletes with Sonya Looney

For this week’s potluck we discuss a host of questions, from getting sick during a target race, training in cold weather, and approaching the off season.

FT294: Racing While Sick, Pro Tips for Riding in the Cold, and How to Rethink the Off Season

In this potluck we discuss what to do when you’re struggling to hang on to a wheel, what the overall goal of training should be, and how to handle needing to poop during a long running event.

Potluck Discussion: Holding a Wheel, GI Issues While Running, and Training Physiology or Performance

Recently, some prominent researchers have suggested that women need far less zone 2 training than previously thought. Physiologists Julie Young and Dr. Dana Lis join us to debate that question.

FT359: Do Women Athletes Need Zone 2 Training?

In this week’s potluck episode, we discuss what coaches should look for in their first conversation with an athlete, how to best do cadence work on the bike, and how to take advantage of group training while not losing sight of your plan.

FT360: Potluck Discussion: First Conversation, Doing Cadence Work, and Training with a Group

Dr. Stephen Seiler joins us to talk about his new project developing a breathing frequency measure and why it may match up better with perceived exertion than heart rate or power. 

FT363: Why Breathing Frequency May Become Our Best Measure of Training Stress

We talk with Dr. Michael Kennedy about his work trying to bridge the knowledge-practice gap between researchers and practitioners.

FT379: Why Researchers, Coaches, and Athletes Need to Work Closely Together

Coaches have known about the importance of durability for years, but researchers are only just starting to catch up. We discuss why it is the fourth pillar of performance.

FT380: Durability: The Fourth Pillar of Aerobic Fitness

TrainingPeaks CEO, Lee Gerakos, joins us to discuss the current trends in training software and where he thinks they are going. 

FT388: The Good, The Bad, and The Ugly Trends in Training Software

Physiologist Jared Berg talks with us about how he uses both in-lab and on-the-road testing to determine what type of work an athlete should focus on. 

FT391: How to Use Physiological Data to Determine the Work You Should Do

We talk with Dr. Jennifer Harris about the critical role that parents play in junior athlete development, and why that role is too often ignored or left undefined. 

FT394: Teaching Parents to Better Support Their Child-Athletes

Dr. Ray Browning joins us to answer a question that even some exercise physiologists get wrong: what is the difference between efficiency and economy? 

FT395: The Difference Between Efficiency and Economy, and Why You Should Care

Experts in medicine, biomechanics, and physical therapy join Dr. Griffin McMath and Trevor Connor to decode the causes of neck pain in cyclists and the strategies that keep athletes strong, steady, and pain-free over the long haul.

FT396: Neck Pain in Cyclists - Mechanics, Fit, and Clinical Insight

Two new studies challenge common assumptions: intensity may matter more than volume for healthy aging, and triathlete injury patterns aren’t what most coaches would predict. We unpack what this means for training prescription, and why neuromuscular and strength work belong in every plan.

FT397: Fast Chats: Rethinking Injury Risk and Longevity—Evidence That Defies Convention

As athletes, we understand the need for training plans, but have you ever considered applying the same principles to your nutrition? This episode discusses how it’s done.  

FT398: Creating Nutritional Training Plans, with MetPro’s Angelo Poli

In this week’s potluck episode, we discuss whether there is a true ceiling to our potential, whether there’s a value in “wintering” or taking time off, and what cross training our hosts recommend.

FT399: Potluck Discussion - Is There a Ceiling, Value of Wintering, and Alternative Training

For our 400th episode we invited three of the most prominent names in exercise physiology to discuss where we are and where we’re going in endurance sports science. 

FT400: The Past, Present, and Future of Sport Science with Drs. Louise Burke, Stephen Seiler, and Iñigo Mujika

This episode highlights the Further Initiative — a groundbreaking research project on female ultra-endurance athletes conducted in partnership with Lululemon and the Canadian Sport Institute Pacific.

FT401: The Further Initiative — What Female Ultra Research Is Teaching Us About Fueling, Recovery, and Performance

Athletes can now perform sweat analysis, check skin temperature, and monitor insulin in the field. But should they? We review the latest in nutrition technologies. We also talk about the potential adverse impacts of carbohydrates and caffeine on our health. 

FT402: Fast Chats - Which Nutrition Gadgets are Worthwhile, Plus Health Impacts of Caffeine and Carbs

Across cycling disciplines, American riders male and female had exceptional success. USA Cycling’s Chief of Sports Performance details the highlights, addresses.

FT403: Celebrating American Cycling Success in 2025, with Jim Miller

The Fast Talk podcast offers the best guides to cycling performance and endurance sports training from world-class experts.

Cohosted by cycling coaches and sport scientists Trevor Connor and Rob Pickels, Fast Talk episodes feature fascinating conversations with world-class experts discussing the endurance sports topics they know best: the best ways to train, effective workouts, questions on polarized and interval training, sports nutrition, physiology and recovery, and sport psychology.

Fast Talk guests and regular contributors include Dr. Stephen Seiler, Joe Friel, Dr. Asker Jeukendrup, Sebastian Weber, Jim Miller, Dr. Andy Pruitt, Dr. Timothy Noakes, and elite professional athletes like Kristin Armstrong, Sepp Kuss, Brent Bookwalter, Kate Courtney, and many more.

Fast Talk is part of Fast Talk Laboratories, a new endurance sports knowledgebase for endurance racers and adventurers.

Fast Talk

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