Exercise Science

What To Do Instead of Zone 2

Tue, 30 Jun 2026 11:02:55 GMT

If you’re a serious recreational athlete but you have a job and a life, and only five hours a week to train — what SHOULD you be doing? Our cardio episodes have to date discussed Zone 2 and explained VO₂max. Armed with that context, now our audience wants to know: If not Zone 2, then what? This week, Stu and Marty provide the answer with the help of one of the world’s foremost experts on aerobic conditioning and the limits of human performance, Dr. Michael Joyner of the Mayo Clinic.

Dr. Joyner is a legend of the exercise science field and an elite runner himself, who back in 1991 conducted the first analysis establishing the physiologic possibility of a sub-two-hour marathon. Since our conversation with Joyner happened to fall just days after Sabastian Sawe and Yomif Kejelcha achieved the first official sub-2:00 marathon times earlier this spring, the conversation begins with a discussion of Joyner’s 1991 analysis.

Then Marty and Stu challenge Joyner to get specific about what amateur athletes should be doing, if they want to achieve the best possible aerobic fitness for health with about five hours a week of training. In other words, what does one of the world’s most renowned scientists at the intersection of human physiology and athletic performance suggest for the optimal training regimen? How much vigorous training should we all be doing, relative to moderate- and low-intensity training? How much HIIT should we be doing? What does Joyner think about Zone 2? What does Joyner do for his own fitness as a 68-year-old man? Plus a listener question asking how to know when you’re training too much.

Have a listener question or an idea for a future episode? Email us at realexercisescience@gmail.com

Exercise Science is powered by EverMe, the longevity intelligence app. Exercise Science listeners get a free two-month trial to EverMe at this link. You can also download EverMe for free at your favourite app store.

SHOW LINKS

Follow or subscribe at your favourite platform @realexercisescience: Substack. YouTube. TikTok. Instagram. Apple Podcasts. Spotify. On X you can find us @realexscience.

Stu is everywhere, too, but mostly on Instagram and X. Follow him on TikTok too!

Marty just started his own Instagram. Give him a follow! He’s also on X!
Exercise Science is produced by Ghost Bureau, the Toronto content agency.

EPISODE LINKS

Two runners break fabled two hour marathon barrier. Friend of Exercise Science Alex Hutchinson wrote about it for The Atlantic.

Joyner’s famous 2011 article: The Two Hour Marathon: Who and When?

Mike Joyner’s 1991 paper that is a staple in Marty’s Integrative Physiology class: Modeling: optimal marathon performance on the basis of physiological factors. PubMed. Full PDF.

Dr. Michael Joyner’s website — been awhile since he updated it but fascinating nonetheless

Andy Jones’ paper referenced by Joyner: The fourth dimension: physiological resilience as an independent determinant of endurance exercise performance - The Journal of Physiology

Adaptations to swimming training: influence of training volume - Medicine and Science in Sports and Exercise

Physiological demands of running at 2-hour marathon race pace - Journal of Applied Physiology

A Perspective on High-Intensity Interval Training for Performance and Health - Sports Med

Physical Activity and Exercise Intensity Terminology - ACSM Position Stand

The “How They Train” series by Fred Wilt

CANADIAN 24-HOUR MOVEMENT GUIDELINES FOR ADULTS (AGED 18-64 YEARS)

Physical Activity Tips for Adults (18-64 years) - Government of Canada

Validity of Submaximal Step Tests - Sports Medicine
Criterion-Related Validity of Field-Based Fitness Tests - Journal of Clinical Medicine

DISCUSSION POINTS

00:00 Intro

02:44 Welcoming Dr. Michael Joyner

03:45 Joyner reacts to 2:00

04:47 Who is Joyner?

06:18 Marathon predictions

11:13 Joyner prediction reception

13:03 Performance determinants

15:51 Other performance determinants

18:59 Elite characteristics

20:50 How elite is elite

22:03 Joyner on Zone 2

26:55 Joyner’s training haiku

29:30 Optimal intensities

30:40 Long intervals key

32:22 Is 80/20 wasting time?

33:43 Resistance training

35:00 Do SOMETHING

36:51 Zone 2 too low

38:51 Vigorous benefits

40:37 What Joyner does

42:35 More haikus

43:59 Listener question

46:52 Wrap up

DISCLAIMER

The Exercise Science podcast is for educational and entertainment purposes only and is not a substitute for professional medical advice. Strength training and fitness carry inherent risks. Always consult with a physician or qualified healthcare provider before starting any new exercise program or making changes to your diet. The hosts, producers, sponsors and guests of this podcast disclaim any liability for any injuries or losses connected with the information discussed in this show.

The science of strength and fitness is continually evolving. While we strive to provide accurate, evidence-based information, we make no representations or warranties regarding the completeness, accuracy, or timeliness of the information discussed.

Martin Gibala is an advisor to and holds equity in Longevity League Ltd., a US-based company whose services in part relate to exercise.

How GLP-1s Affect Muscle Mass

Tue, 23 Jun 2026 10:46:09 GMT

Semaglutide, sold as Ozempic and Wegovy, and tirzepatide, sold as Zepbound and Mounjaro, are new weight loss drugs that actually work, helping millions around the world to feel better and become healthier. But some people are fearful of side effects, such as loss of muscle mass. Are their fears warranted?

To find out, Marty and Stu talk to the two University of Kansas weight loss scientists, Renee Rogers and ACSM president-elect John Jakicic, who are leading a clinical trial investigating the way aerobic and resistance training can affect the muscle mass of people who are on GLP-1s, or the other new weight loss drugs.

In this episode we discuss:

—the latest findings on how GLP-1s affect muscle mass
—the difference between lean mass and muscle mass
—the research that Jakicic and Rogers are doing into GLP-1s, weight loss and muscle mass
—we provide guidance on whether people should be concerned about GLP-1s and muscle mass
—we also provide pointers on how to minimize muscle loss while on GLP-1s

Plus, Renee and John answer a listener question about whether the new weight loss drugs affect men and women differently.

Have a listener question or an idea for a future episode? Email us at realexercisescience@gmail.com

Exercise Science sponsor Precision Nutrition is the #1 most recommended nutrition certification program in the world. And now it specializes in GLP-1 coaching. For a free assessment to learn your GLP-1 type, visit GLPCoaching.com.

LINKS

Follow or subscribe at your favourite platform @realexercisescience: Substack. YouTube. TikTok. Instagram. Apple Podcasts. Spotify. On X you can find us @realexscience.

Stu is everywhere, too, but mostly on Instagram and X. Follow him on TikTok too!

Marty just started his own Instagram. Give him a follow! He’s also on X!
Exercise Science is produced by Ghost Bureau, the Toronto content agency.

EPISODE LINKS

New York Times: They Hated Exercise. Weight Loss Drugs Changed Everything.

Renee Rogers and John Jakicic’s clinical trial: Muscle and Movement With Anti-Obesity Medications (M3)

A paper by John Jakicic and Renee Rogers advocating for a prescription of exercise along with obesity medication in obesity treatment: The Role of Exercise in the Contemporary Era of Obesity Management Medications - ACSM-CSMR

Jakicic led, and Rogers coauthored, the largest targeted NIH investment of funds into the mechanisms of how physical activity improves health and prevents disease. Study website. Article from the Journal of Applied Physiology: Molecular Transducers of Physical Activity Consortium (MoTrPAC): human studies design and protocol

Analysis: Preserving muscle mass on GLP-1 weight loss drugs: Big Deal or Nothing to Worry About? By Stuart Phillips

DISCUSSION POINTS

00:00 Cold open

01:29 Muscle mass and GLP-1s

04:19 Introducing Renee and John

06:19 GLP-1 context

07:50 How GLP-1s work

10:50 More than GLP-1s

12:44 Body composition & weight loss

15:00 Lean tissue is not muscle

16:50 Overblown fears

18:55 Muscle moment

20:39 R01 study described

23:15 Early results

26:04 Behavioural influences

28:45 Rediscovering exercise

31:09 Comprehensive care

33:00 Renting weight loss

36:55 Obesity drivers

37:47 Older adults

40:39 Wraparound care

41:30 Muscle health context

43:12 Function measures matter

44:44 Lean v. muscle

46:15 Unloading the body

47:40 GLP-1 sex differences

49:44 How to minimize muscle loss on GLP-1s

53:33 Wrap up

DISCLAIMER
The Exercise Science podcast is for educational and entertainment purposes only and is not a substitute for professional medical advice. Strength training and fitness carry inherent risks. Always consult with a physician or qualified healthcare provider before starting any new exercise program or making changes to your diet. The hosts, producers, sponsors and guests of this podcast disclaim any liability for any injuries or losses connected with the information discussed in this show.

Martin Gibala is an advisor to and holds equity in Longevity League Ltd., a US-based company whose services in part relate to exercise.

VO₂max: The Fifth Vital Sign

Tue, 16 Jun 2026 09:55:56 GMT

VO₂max is the most important metric of your overall cardiorespiratory fitness. It’s a measure of the maximal ability of your body to take in and use oxygen. But what does the number actually mean for your health and longevity? Why is it important to know your VO₂max? What’s the most effective way to improve your VO₂max, whether you’re an athlete or just someone seeking to improve your health? And what does this all have to do with beer-league hockey, and everybody’s favourite Sudbury Blueberry Bulldog, Shoresy?

In this episode, Stuart Phillips asks Martin Gibala to break down VO₂max in plain English: what it is, why it matters, and how it shapes everything from your risk of dying to how fast you can run a 10K. And just to get the kin grad students among us even more excited, this episode namedrops the Hickson Protocol, plus legends of kinesiology like Robert Ross, Ulrik Wisløff and Carsten Lundby. Pitter patter, let’s get at ‘er!

Have a listener question or an idea for an episode? Email us at realexercisescience@gmail.com

Exercise Science is powered by EverMe. Download EverMe for free at your favourite App store.

EPISODE LINKS

A Case for Fitness as a Clinical Vital Sign: The academic paper Marty references, that argues that MDs should assess VO₂max during each patient visit.

Biology of VO₂ max: looking under the physiology lamp by Carsten Lundby and Mike Joyner. Here’s the 2015 review by Lundby that references a top VO₂max reading of 90.6. And then here’s a 2019 case study from Lundby and Joyner that references the physiological profile of Norwegian cyclist Oskar Svendsen, who recorded a staggering 96.7 mL/kg/min in a laboratory.

The Hickson protocol is described here, featuring six sessions per week, including three sessions of continuous vigorous in which the athletes ran as far as they could in 40 minutes, interspersed with three interval training bouts per week. The interval training amounted to six sessions of five-minute-long intervals during which the athletes tried to achieve VO₂max in each interval, interspersed with two minutes of easier cycling. Pretty intense!

Protocols to test VO₂max by proxy: YMCA fitness test is described in this academic paper. Plus here’s a better description of the 3-min step test.

A survey-based non-exercise predictor of VO₂max is found at worldfitnesslevel.org.

VO₂max test footage from McMaster University

Wisløff Hunt Study one high-intensity bout of week v. cardiac risk

Wisløff 2001 out of Norwegian University of Science and Technology with elite male junior soccer players, 2x a week for eight weeks boosted VO₂max by 11%.

Wisløff 2008 with sedentary middle-aged men and women with metabolic syndrome, 3x a week for 16 weeks, improved VO₂max by 35%, more than twice as much as a control that performed continuous moderate exercise.

Martin Gibala contributed to Wisløff’s 2013 paper, showing most of the benefits from an interval workout come from the first sprint.

SHOW LINKS

Exercise Science is everywhere @realexercisescience: Substack. YouTube. TikTok. Instagram. Apple Podcasts. Spotify. On X you can find us @realexscience.

Stu is everywhere, too, but mostly on Instagram and X. Follow him on TikTok to make him feel nice!

Marty just started his own Instagram. Give him a follow! He’s also on X!

Exercise Science is produced by Ghost Bureau, the Toronto content agency.

DISCUSSION POINTS

00:00 Cardio v. Strength

02:08 VO₂max explained

06:08 Heart’s role

08:41 Clinical vital sign

10:36 Benefits of boosting VO₂max

12:11 Assessing VO₂max

13:51 Ulrik Wisløff

15:15 Beer league hockey

17:07 VO₂max ranges

20:59 More boosting benefits

24:16 VO₂max trainability

27:00 Highest recorded values

29:30 How to improve VO₂max

31:27 Hickson protocol

33:38 Fastest way to boost

DISCLAIMER

Martin Gibala is an advisor to and holds equity in Longevity League Ltd., a US-based company whose services in part relate to exercise.

Brad Schoenfeld's Top 5 Strength Myths

Tue, 09 Jun 2026 09:55:59 GMT

Think you know how to build muscle? In our third episode, co-host Martin Gibala does some mythbusting with two of the world’s most prominent experts in the science of strength development, co-host Stuart Phillips and special guest Dr. Brad Schoenfeld, a professor of exercise science at Lehman College in the Bronx, New York.

In addition to being a former bodybuilder and joining Stu on the ACSM strength position statement, Schoenfeld literally wrote the textbook on strength training. Together, Phillips and Schoenfeld use science and savvy to correct some of the resistance world’s most pervasive myths, including:

Light loads don’t increase muscle size
Train to failure to maximize muscular adaptations
Short rest periods are best for hypertrophy
Cardio kills gains
Narrow post-exercise anabolic window of opportunity

Join us to discuss these myths and more in the latest episode of Exercise Science!

Have a listener question or an idea for an episode? Email us at realexercisescience@gmail.com

Exercise Science is powered by EverMe. Download EverMe for free at your favourite App store.

LINKS

Exercise Science is everywhere @realexercisescience: Substack. YouTube. TikTok. Instagram. Apple Podcasts. Spotify. On X you can find us @realexscience.

Stu is everywhere, too, but mostly on Instagram and X. Follow him on TikTok to make him feel nice!

Marty just started his own Instagram. Give him a follow! He’s also on X!

Whoa Brad Schoenfeld is HUGE on Instagram! One of the best feeds out there for the up-to-the-minute science on strength training. Plus here’s his lab at Lehman College.

ACSM Position Statement on Resistance Training 2026

Brad’s textbook: Science and Development of Muscle Hypertrophy, 2nd Edition

Resistance Training Beyond Momentary Failure - Brad Schoenfeld, co-author
Divergent strength gains but similar hypertrophy after low-load and high-load resistance exercise training in trained individuals: many roads lead to Rome

Exercise Science is produced by Ghost Bureau, the Toronto content marketing agency.

DISCUSSION POINTS

00:00 Who is the strongest exercise scientist?

02:13 Schoenfeld intro

03:47 Myth 1: Must lift heavy

06:25 Myth 2: Must train to failure

10:52 Myth 3: Short rest periods

17:26 Myth 4: Anabolic window

26:33 Myth 5: Cardio kills gains

36:54 LQ: Losing gains

DISCLAIMER

Much Ado About Zone 2

Tue, 02 Jun 2026 10:55:57 GMT

Influencers can’t get enough of Zone 2 training. So why did Martin Gibala publish a research paper challenging Zone 2 for the general public? In this episode, Stuart Phillips leads Marty through a critical examination of Zone 2.

Marty suggests that very little scientific research exists to support Zone 2 training intensity for most people—either as an effective stimulus for cardiorespiratory fitness or mitochondrial capacity. In fact, if you do between three and six hours of cardio a week, Marty believes that Zone 2 isn’t hard enough for you to efficiently accrue training benefits. In other words, if you’re an amateur athlete subscribing to the much-vaunted rule that 80% of your cardio should be in Zone 2, you’re not as fit as you otherwise could be.

So what is Zone 2 training? And is Zone 2 causing many people to exercise inefficiently, leaving them less healthy than they otherwise might be? What should people be doing INSTEAD of Zone 2? It’s all here, in the latest episode of Exercise Science!

Have a listener question, a comment or an idea for an episode? Email us at realexercisescience@gmail.com

LINKS

Marty and Brendon Gurd’s critical examination of Zone 2: Much Ado About Zone 2: A Narrative Review Assessing the Efficacy of Zone 2 Training for Improving Mitochondrial Capacity and Cardiorespiratory Fitness in the General Population

Marty’s coauthor Brendon Gurd on their Zone 2 paper at the Discover Strength podcast.

Luke Carlson calls the “Much Ado About Zone 2” paper the most important scientific publication of 2025 in this blog post summarizing the paper.

HIIT and Zone 2: Marty on the Discover Strength podcast

Sperlich paper referenced in this episode: Zone 2 Intensity: A Critical Comparison of Individual Variability in Different Submaximal Exercise Intensity Boundaries

Marty was a coauthor on this ACSM/ESSA position statement on exercise intensities

Marty was senior author on this Sports Medicine paper on exercise intensity in high-intensity activity, which features the intensity diagram Marty mentions

Referenced in this episode: Defining Training and Performance Caliber: A Participant Classification Framework

Lifehacker’s Beth Skwarecki notes, Nobody Can Agree On What Zone 2 Is

Oura’s heart rate zones

Whoop band’s heart rate zones

Garmin’s heart rate zones

Peter Attia on Zone 2: This Is How You Know If You’re in Zone 2 When Doing Cardio

More Attia: This is What Zone 2 Training Looks Like

Attia saying 80% of cardio should be Zone 2

Origins of Zone 2: Attia and San Milan in the early days of the trend

Find Stu Phillips on most platforms @mackinprof

Find Martin Gibala on Instagram, which he just joined, @gibalamj

Exercise Science is powered by EverMe. Download EverMe for free at your favourite App store.

DISCUSSION POINTS

00:00 Exercise fads

00:34 Intros

02:30 What Zone 2 is

04:21 No uniform definition

06:02 Lactate threshold

08:10 Zone 2 marker variability

09:54 Ventilatory threshold

11:57 Conflation with moderate

12:58 Improving exercise prescriptions

14:40 Health v. performance

16:04 Moderate intensity is better

16:58 80/20 split

18:45 Better alternatives

19:47 Zone 2 origins

20:39 Wearable intensities

22:09 Threshold testing options

23:14 Training for health

24:21 Take-home message

26:05 Vigorous is better

26:44 Listener question

DISCLAIMER

Strength Training for Everybody!

Tue, 26 May 2026 09:56:03 GMT

Forget the oiled-up pumping-iron musclehead stereotype. In 2026, strength training is officially for EVERYONE. The question: What took so long?

In the premiere episode of the Exercise Science podcast, Martin Gibala takes his co-host Stuart Phillips through the recently released landmark update that Phillips senior authored: The American College of Sports Medicine (ACSM) Position Stand on Resistance Training Prescription for Muscle Function, Hypertrophy, and Physical Performance in Healthy Adults.

It’s the first position statement in 17 years from the gold standard exercise organization, and, according to the ACSM itself, “the most comprehensive evidence-based guidance to date on how resistance training supports muscle strength, muscle size (hypertrophy), power, and physical performance across adulthood.”

Parsing the science, together, Stu and Marty break down why strength is the ultimate compound interest investment for your health span. How important is strength training? Why should you consider strength training 2x per week to be just as important as the other main exercise-related health guideline, 150 minutes of moderate-intensity exercise per week?

Plus: How much strength training is enough? What’s the minimum that you should do? What changed during the 17 years between position stands? And how did a 1940s bodybuilding doctor rehabbing soldiers pave the way for modern strength training?

If you’re going to listen to just one podcast about the 2026 ACSM position stand on strength training — make it this episode of Exercise Science!

LINKS

Exercise Science is everywhere @realexercisescience: Substack. YouTube. TikTok. Instagram. Apple Podcasts. Spotify. On X you can find us @realexscience.

Stu is everywhere, too, but mostly on Instagram and X. Follow him on TikTok to make him feel nice!

Marty just started his own Instagram. Give him a follow! He’s also on X!

Thanks to our season one sponsor: EverMe is longevity intelligence — and you can download it for free at your favourite App store.

ACSM Position Stand 2026: The scientific article in Medicine & Science in Sports & Exercise

Here’s the press release about the stand from the ACSM, and a great succinct infographic summarizing the main takeaways

Here are the two previous ACSM position stands on strength: 2009 and 2002

Thomas L. DeLorme and the Medical Acceptance Of Progressive Resistance Exercise - Iron Game History

Thomas L. DeLorme and the Science of Progressive Resistance Exercise - Journal of Strength and Conditioning Research (Abstract)

One of four students on the position stand, Brad Currier brought the evidence together, did most of the writing and herded the cats

All about Ken Cooper, a seminal expert on aerobic fitness who came to understand the importance of strength training

Honoring the legacy of Steve N. Blair, a giant in the field of exercise epidemiology

Marty and Stu’s MOOC: Hacking Exercise for Health

Exercise Science is produced by Ghost Bureau in Toronto.

DISCUSSION POINTS

00:00 Marty teases Stu

01:20 Episode outline

02:34 What’s a position stand?

03:36 What is the ACSM?

03:52 Building the team

05:00 What’s new in 2026

06:20 Levels of scientific papers

07:10 2026 v. 2009

08:12 Recommendations

09:30 Effort v. failure

10:38 Volume of training

12:30 Home-based options

14:06 Advice for newbies

15:13 Strength explained

18:57 Power explained

19:37 Why now?

22:17 Weight training for women

23:03 Capt. Thomas L. Delorme

25:36 Circus strongmen

26:30 Outdated philosophies

28:01 Barriers to entry

29:33 No pain, no gain is dead

31:45 Safety

33:30 Where to start

35:00 Takeaways

35:50 Listener question

36:50 Outro

DISCLAIMER

Exercise Science Podcast Coming Spring 2026

Thu, 21 May 2026 14:39:19 GMT

Kinesiology professor Martin Gibala is the worldwide expert on time-efficient cardio. Kinesiology professor Stuart Phillips is the global expert on strength, muscle development and protein. In Exercise Science, these two friends and colleagues translate the world of exercise science for the rest of us — separating the hype from the hard evidence.

Exercise Science Podcast Coming Spring 2026

Exercise Science — Fri, 13 Mar 2026 15:46:19 GMT