Mastering Interval Training for Ultrarunners with Michael Rosenblat, PhD #198
Episode overview:
Michael Rosenblat is a researcher and coach with expertise in kinesiology, physiotherapy, and exercise science. In this episode we discuss his three most recent meta-analyses on interval structure, including how to translate cycling intervals to protocols for runners, interval duration and macrostructure, and the relationship between VO2peak and time trial performance.
Episode highlights:
(14:24) Translating interval structure: it depends, direct translation usually works, tendon loading, injury prevention, recovery, metabolic load is probably 1:1
(32:59) HIIT volume: example of 20x1min versus 4x5min, metabolic differences, total session volume does not correlate with improvement, duration of work bout does, maximizing versus optimizing time at intensity
(51:14) VO2max vs. performance: %change in VO2peak does not correlate with %change in performance, Paula Radcliffe example, VO2max plateaus with years of training but performance keeps improving, CTS lab example
Our conversation:
(0:00) Introduction: getting back to a normal schedule after losing podcast equipment on the return from UTMB, practical applications of interval training in ultrarunners
(2:51) Michael’s background: combining coaching and research, starting as a triathlon coach, pursuing a degree in kinesiology and later physiotherapy, influences from Stephen Seiler, working for Triathlon Ontario, going back for PhD in Exercise Science
(7:12) Pivoting research due to Covid: changing from lab work to biostatistics and meta-analyses
(8:19) The perfect coaching toolkit: combining research, coaching, physiotherapy, and athletic experience benefits all four
(9:14) Meta-analyses and cycling: why tests are usually performed on cyclists, research ethics and safety concerns, injury rate is higher in runners
(12:55) Cycling applications to running: VO2max translates, limitations with lack of specificity, efficiency, tendon loading, examples
(14:24) Translating interval structure: it depends, direct translation usually works, tendon loading, injury prevention, recovery, metabolic load is probably 1:1
(17:21) Michael’s 3 meta-analyses: interval design for maximum oxygen uptake, peak power output, performance, themes, intervals should be aligned with the physiological stress you are trying to achieve and not the distance you are training for, examples
(20:50) Keeping it simple: entertaining intervals and complication for the sake of complication, physiological mismatch in interval design
(23:15) Sprint interval training (SIT) and high intensity interval training (HIIT): HIIT intensity within the lactate threshold to VO2max range is the same for performance, HIIT duration at that intensity matters, research questions, longer duration is better, time to get to peak oxygen uptake
(27:15) Optimal HIIT: 5-7 minutes is likely best, acute responses versus physiological adaptation
(28:47) The HIIT intensity range: discussion outline, the bottom of the range is the highest sustainable steady-state oxygen level, usually sustainable for 30-60 minutes, oxygen consumption increases within the range, 2 minutes at the high end of the scale
(32:59) HIIT volume: example of 20x1min versus 4x5min, metabolic differences, total session volume does not correlate with improvement, duration of work bout does, maximizing versus optimizing time at intensity
(34:56) Digging into “it depends”: recap of HIIT, what HIIT structure depends on
(37:02) Intervals and training status: training status matters because untrained athletes will improve regardless, consistency matters most, personal anecdote
(39:28) Goals of HIIT: peripheral versus central adaptations, SIT versus HIIT, peripheral adaptations occur first, physiological mechanisms
(42:00) Training cycle: examples, specificity for race preparation, Koop’s least to most specific structure
(43:32) The zone 2 craze: attention shifts with the endurance community, zone 2 seems to have no ceiling for improvement
(45:50) HIIT and zone 2: you always need a combination of intensities
(47:15) Meta-analyses methods and results: meta-analyzing VO2peak, time trial performance, and velocity peak, intensity improves VO2peak, same 3-6% performance improvement between recreationally and competitively trained athletes
(49:15) Caveats with study design: one mesocycle, 2-12 week interventions, well trained individuals may take more than 12 weeks to improve
(51:14) VO2max vs. performance: %change in VO2peak does not correlate with %change in performance, Paula Radcliffe example, VO2max plateaus with years of training but performance keeps improving, CTS lab example
(53:38) check out figure 3: an accessible graph to summarize the data, describing forest plots, study and interval design construction, illustrating 30s to 8 min intervals
(55:35) Takeaways for athletes: add HIIT to your program, sample size issues might be why interval training was not shown to be more effective in the meta-analyses, challenges with statistical power
(57:57) 1999 Stepto study: a pioneering study comparing interval construction, challenges with statistical power
(58:50) Progressive overload: changing interval construction with athlete experience, the interval workouts themselves don’t change but the weekly and monthly concentration of work does, examples
(1:01:30) Interval recovery: caution around 3+ interval sessions per week, just because you can handle it doesn’t mean you should, balancing cardiovascular, respiratory, and peripheral responses
(1:03:31) Load and shifting intensity domains: increasing workout time at intensity will eventually necessarily change the intensity domain, thus changing macro or meso-structure is more effective in trained athletes
(1:05:06) Restructuring yearly training: elite athlete examples, more is not necessarily better, avoiding risk and injury, exceptions
(1:07:04) Wrap-up: talk to your coach, think about your goals, work on your limitations, consistency is most important, where to find Michael, Veronique Billat, seeing through hype cycles in training
(1:10:45) Outro: giving thanks, share the KoopCast, episode 63 with Stephen Seiler
Additional resources:
Michael’s website- evidencebasedcoaching.ca
Papers discussed-
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Information on coaching-
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Twitter/Instagram- @jasonkoop