'The biggest game-changer in the history of endurance sport was the power meter,' Joe Friel's training wisdom

For more than four decades, Joe Friel has been one of the most influential voices in endurance sport. Long before training metrics, training with power, and performance dashboards became part of every cyclist's vocabulary, Friel was helping athletes understand how to train smarter, recover better, and reach their potential.

His landmark book The Cyclist's Training Bible, first published in 1996, has become one of the most successful and enduring coaching guides ever written, shaping the training of everyone from weekend riders to elite racers. Its principles remain as relevant today as they were three decades ago, with the book now in its fifth edition. Friel's impact extends far beyond the printed page.

In 1999, alongside his son Dirk and colleague Gear Fisher, he co-founded TrainingPeaks, the coaching and analysis platform that transformed how athletes and coaches track performance. TrainingPeaks remains one of the most widely used training tools in pro and amateur cycling.

Now, with the release of an updated version of his acclaimed training guide, Fast After 50: How to Race Strong for the Rest of Your Life, Friel is once again challenging conventional wisdom. Drawing on a coaching career that stretches back to 1980, a Master's degree in exercise science, and experience working with everyone from first-time competitors to national champions and Olympians, he argues that many riders are making training more complicated than it needs to be, explains how sleep underpins performance, and why motivation matters more than talent.

Q: How did you first get into running and cycling?
A: I've always been fascinated by training. I started when I was about 12 years old and, looking back, it's just something that's always been part of who I am. Sport was the thing I enjoyed most, so throughout high school and college I looked for every opportunity to be involved, especially in track and field. Unlike my peers, I didn't stop when the season ended. I'd go out running, lift weights, and train simply because I loved it. Most people thought I was a bit strange, but I never lost that enthusiasm.

Even when I was serving with the US Air Force in Vietnam, I found ways to keep training; exercise remained a constant wherever life took me. That passion eventually became my career. I earned a Master's degree in exercise science and began as a marathon runner and running coach in the 1970s, before moving into triathlon coaching in 1983. Today, I live in the mountains of northern Arizona and I'm still doing what I've always loved - training, coaching and writing.

Q: When you started coaching endurance athletes in 1980, what were the biggest misconceptions about training?
A: First, that easy workouts were just for recovery. They're not - they're the foundation of endurance fitness and often deliver the greatest long-term gains. Second, that training should stay the same year-round. No. Fitness develops through changing phases that build, sharpen and refresh performance. And third, that coaching was only for elites. Untrue. Any rider can benefit from expert guidance, structure and accountability, especially when training time is limited.

Q: Which innovation has transformed performance, and which has been overhyped?
A: The biggest game-changer in the history of endurance sport was the power meter in the late 1980s. Cycling especially went from the least precise and technical endurance sport to the most because of it. Now there are several sports that have power meters, and our knowledge of how to train with power continues to grow, as seen in the many concepts TrainingPeaks has developed. So far, wearables have not lived up to their hype. Many are simply inaccurate. I think that status will change positively when the continuous lactate monitor eventually hits the market. That will also bring about more revolutionary training changes.

Q: Many riders know concepts such as periodisation, training zones and structured planning because of your work. Which coaching principle do you feel has had the greatest impact?
A: The most beneficial of those three was periodisation. Although it had been in use by a few Western elite athletes starting in the 1970s - mostly in running - up until I wrote about it in my first book, The Cyclist's Training Bible, it was mostly misunderstood and unused by age-group athletes.

Q: Looking back at the athletes you've coached, what separates those who fulfil their potential from those who don't?
A: Motivation, not talent, is the biggest determiner of success in sport. But it's got to come from within. A coach can do little to inspire the athlete's success. I once coached a pro rider who was world-class but would not ride if it looked like it might rain. And his reluctance went well beyond this. He was still a top-10 finisher at major events. With even moderate internal drive, he'd have had the potential to be a world champion. I've also coached amateur athletes who had tremendous motivation but little talent. I would much rather coach the latter.

Q: How do you balance trusting research against trusting your own observations?
A: Generally, I like to understand what science suggests when it comes to deciding how to prepare an athlete for competition. Then again, athletes are unique in so many ways that it is sometimes a challenge to apply what you find in the research. There are studies that need to be read with a bit of scepticism when it comes to application, such as those with a very small or a narrow subject range, or which exclude women or novices. Unfortunately, such limitations are quite common in sport science.

Q: If an ambitious club cyclist came to you today with 10 hours a week to train, what would be the first thing you'd look at before prescribing a programme?
A: How high are they aiming? If the aim is so high that it may be pushing their training time limits, then the next matter is sleep. If it is inadequate, then the chances of success are slim. The athlete who gets even slightly inadequate sleep probably has too much 'stuff' in their life - responsibilities, stress, activities. It's during sleep that fitness is built. It must be protected. For the time-crunched, wannabe high-achiever, there can be only three things in life: family, career, and training. Everything else must be sacrificed to be truly committed to a high goal.

Q: You have often spoken about the importance of an aerobic foundation. In an era obsessed with intervals and intensity, why is endurance still the cornerstone of cycling performance?
A: There are several physiological benefits of low-intensity, aerobic training in Zones 1 and 2 that cannot be achieved with high-intensity riding in the higher zones. Here are some: superior muscle capillarisation, increased mitochondrial density, raising the effort for burning fat for fuel, increased left ventricle size of the heart, which is the greatest determiner of VO2max, and stimulation of the parasympathetic nervous system, which aids recovery from stress.

Q: What training mistake do you see experienced cyclists making repeatedly, regardless of age or ability?
A: The biggest, by far, is doing too much moderate-intensity training. They may have the best of intentions at the start of a ride to stay in Zones 1 and 2, but they soon let it rise into Zone 3. If intensity becomes even slightly too high - above the first lactate threshold, at the top end of Zone 2 - it will take some time for the body to regain the benefits of low intensity, as described above. The most common reasons for this are loss of concentration, the course being too hilly, and 'half-wheeling' a training partner.

Q: You've coached through several generations of athletes. Are today's cyclists fundamentally different from the athletes you worked with in the 1980s and 1990s?
A: Yes, today's athletes are much better informed when it comes to training. Amateur cyclists are now more knowledgeable than coaches were 20 years ago. This is due to increased internet information, magazine coverage of training, study of training devices such as power meters, and understanding the many workout details provided on platforms like TrainingPeaks.

Q: For riders over 50, what is the single most important lesson you've learned about maintaining performance as we age?
A: Beyond a certain age, fitness, especially aerobic capacity, declines at a rapid rate if training is inconsistent. Consistent training is more important once the rider is in their 50s than it was when in their 30s and 40s. The loss is inevitable but can be slowed to less than 1% per year with timely and effective training.

Q: If you could go back and give your younger coaching self one piece of advice in 1980, what would it be?
A: The most important aspect of effective coaching is your personal relationship with the athlete, rather than the science of training or your knowledge of equipment. The coach-athlete relationship is the key to coaching success. That relationship starts with the simple concept that the athlete is your employer and the boss. You are doing this for them - not yourself.

Q: When future historians look back at the evolution of endurance coaching, what development do you think will be seen as the defining change of your era?
A: Mass participation in endurance sport has been a defining characteristic of the era from the 1970s to the present time. This is why there are so many coaches. Previous generations saw sport as something they neither could nor should do with their time. Bear in mind, they were the indirect heirs of the Great Depression of the 1930s. That group saw the world entirely differently to later generations, and with good reason.

Q: After more than 40 years of coaching, writing and helping shape the way cyclists train, what still excites you about the sport today?
A: I still love learning about the latest ideas in sport science and how those concepts can be used not only to improve performance, but also simplified so that the age-group athlete can understand them and apply them to their own training and racing.

The second edition of Joe Friel's Fast After 50: How to Race Strong for the Rest of Your Life is out now (Velo Press, £20.99)

Joe Friel's CV

• Age: 82
• Hometown: Sedona, Arizona, USA
• Notable athletes coached: Ryan Bolton, Olympian and Ironman champion; Gordo Byrn, Ultraman world champion; Simon Thompson, Australian Olympic triathlete; Carol Montgomery, Olympian and Pan American Games gold medallist.
• Best achievements as athlete: 1st - Colorado State Masters Triathlon Championship (1985); multi USA Triathlon All-American Duathlete.
  Best achievements as coach: Multi National Championships (pro and amateur); 2002 Ironman Triathlon winner Ryan Bolton; 2002 Ultraman World Championships winner Gordo Byrn.
• Favourite motto: "Doing the wrong workouts consistently is better than doing the right workouts inconsistently."