December 1, 2022

Looking for the best interval workout? Here it is

Scientists and coaches have long known that boosting a runner’s vo2 max is just about the surest way to help him/her run faster. But what’s the best way to improve your vo2 max? Well, with interval training, of course. That’s been largely agreed-upon for 70 years. Which leads to the next question: What’s the best interval workout to increase your vo2 max? 


A new paper tackles that problem head-on. It gave healthy young male runners one of three different interval workouts that they performed 24 times over an 8-week period. Here are the workouts: 4 x 4 minutes at 95 percent of MAS (max aerobic speed) w/ 3 minute “active breaks” between repeats; 12 x 20 second sprints at 150% of MAS with short 10 second passive breaks; and 10 x 30 second sprints at 175% MAS with long 3.5 minute active breaks. 


We’ll call these three workouts HIT, SIT20, and SIT30. HIT stands for “high intensity training” and SIT is “sprint intensity training.” 


All subjects received a number of different tests before and after their 8-week training programs. The test we’re most interested in was a 3000-meter time trial. The HIT runners improved significantly more on that test (by 5.9%) than the SIT runners. Although SIT20 was an impressive second, apparently because the very short rest periods made the workout almost as continuous as the 4-min repeats. (The SIT20 also did the best job of the three workouts at improving 300-meter sprint times--a good thing to have if you’re a serious track competitor.) 


The researchers concluded: “HIT 4 x 4 intervals are superior at increasing vo2 max compared to SIT protocols … and should be the recommended interval format for aerobic performance.” Also, SIT20 workouts “may be a supplement for enhancing the anaerobic fraction of events.”

 

They added an important note about SIT training. It’s really hard, to the point where it might not be advisable. “Subjects reached absolute exhaustion during the SIT intervals,” with some experiencing “nonsevere adverse effects” such as nausea, vomiting, and dizziness. “Therefore it should be questioned if the extremely intense and fatiguing nature of SIT is appropriate” in all populations. In other words, don’t try SIT workouts unless you’re fit and highly motivated. More at Scandinavian Journal of Medicine & Science in Sports


How do you know you need a recovery day?

We all know our training plan must include hard days and easy days. But what’s the right ratio between them? Should it be 1:1 or 1:2 or 1:3, or some other ratio? Other important, related questions: How should this ratio change by training volume and intensity, or by age and sex? 


Endurance expert Alan Couzens thinks a measurement like morning heart rate (or HRV, heart rate variability) is the way to go. Check every morning, then decide on your training for the day. It’s a simple, objective measurement. “It's silly to set your training plans to arbitrary cycles of load & recovery (3:1, 4:1 etc),” Couzens notes. “Your body's readiness for training is cyclical, but not predictable, even for a very stable athlete. In other words, take recovery when your body says, not when ‘the plan’ says.” 


But Couzens’s tweet drew a contrary view from another exercise expert, Inigo San Millan. He responded: “In many instances when an athlete is fatigued it may be [too] late and it’s key to be ahead of it. I always go with a plan and check multiple parameters, especially blood biomarkers to check that training is assimilated correctly.” 


They both make good points. I lean toward conservative approaches, so I favor San Millan’s perspective. But it couldn’t hurt to also include HRV as part of your evaluation process. 


Should you fast, or fuel up, for afternoon/evening runs?

There’s been a fair amount of research into morning runs performed after an overnight fast (while you’re asleep.) For the most part, these runs increase your fat burning (which could be a good thing) but decrease the performance of your run. That is, you probably go slower and/or shorter, and don’t feel as good. So there are pros and cons to the unfueled morning run. That’s why some coaches and exercise physiologists recommend that you do both to maximize both endpoints--fat burning and performance.

 

Much less is known about afternoon runs while you are fed vs underfed. Here researchers compared subjects who performed an endurance test (at 6:30 pm) after 7 hours of fasting (since an 11:30 am lunch) or 2 hours after a 540-calorie meal. Results? The 7-hour fasters ended the day with a 440-calorie intake deficit vs the 2-hour runners, so the approach might help you lose a few pounds. In addition, the 7-hour fasters burned more fat while running. “However, fasting also reduced voluntary performance, motivation, and exercise enjoyment.” So, once again, there are two sides to the strategy. More at Int J of Sports Nutrition & Exercise Metabolism. 


6 sports nutrition myths, including a view on fasting

There’s a lot of confusing, often contradictory, and not-evidence-based sports nutrition information all across the internet. Here sports nutritionist and former elite cyclist Anne Guzman notes 6 that she labels “myths.” You’ve probably heard that moderate caffeine/coffee consumption doesn’t dehydrate you; Guzman agrees with that, and offers some context.  


Most interesting is her thinking about intermittent fasting and training while fasted--in the morning before breakfast, for example. (Or as just discussed in the above item on afternoon/evening workouts.) Guzman doesn’t think these will do much for your weight loss efforts. However, she adds: “I'm not dogmatic about not training fasted since there is some interesting science around the adaptive response to training fasted related to metabolism.” More here. 


Simple workouts can be powerfully productive

Some workouts are unusually successful because they are simple, hard (and therefore effective), and also well named. They’re easy to remember, and they get the job done, which encourages you to return to them with some regularity. The best example of this is Yasso 800s. 


David Roche came up with another one recently, primarily by naming it well--“The Power Hour.” Who doesn’t want more power? Who isn’t willing to give up an hour to achieve more power? Roche and his wife, Megan, define their workout as follows: “The Power Hour is something between a normal tempo run and a race simulation, starting moderate and ending hard, ideally over race-specific terrain.”


You can’t go wrong by trying this session now and then (but not too often), so what are you waiting for? The article got stuck behind a paywall at Trail Runner but is free at Yahoo.  


A sneak peak at the new book Born To Run 2

You would have expected this book a decade ago. After all, the original anti-shoe, pro-Tarahumara best selling adventure tale came out in 2009. Most writers and publishers would have launched the “how to do it yourself” edition a couple of years later. But Chris McDougall is a war-reporter at heart--he lives for the chase and discovery. He’s not your typical “how to” advice author, and I admire him for that. So he held out as long as he could before producing B2R2. 


But eventually his coach, Eric Orton, or his publisher applied more pressure. Now we have Born to Run 2--one of the clunkiest book titles ever. I didn’t expect to like B2R2, or to learn anything from it. I was wrong on both counts.  


The book is lively and fun--all credit to McDougall’s writing skill. The photography is fantastic. And I definitely learned things I had never encountered in 60 years of reading running material. Especially the strange indoor running form drill powered by “Rock Lobster” from the B-52s. I’ve actually done it a few times at home (with YouTube music), and it’s a good one. The drill is included in this book excerpt at Outside Online. 


The best way to make certain you DO that next run

Many years ago a running coach-friend told me that the most popular page on her jam-packed website was a downloadable 7-day calendar. People printed it out, and put it on the front of their home refrigerator. Never underestimate the power of a strong visual cue. 


Here a runner and exercise scientist explains her personal favorite motivational ideas. I found myself drawn to the visual ones. “Sticky notes on a mirror, alerts on your phone, running gear laid out the night before — will make it as easy as possible to get going when you’re busy.” 


For some reason, my brain clicked an extra notch, and I thought: I bet gross visual cues would be even better. How about running shoes on the kitchen counter or toilet seat? [Report back when you’ve accumulated enough data.] More at NYTimes.com 


Carbs: The never ending story

Research into carbohydrates and exercise performance is never ending, always expanding, and often revealing new insights. Alex Hutchinson recently explained how carbs improve recovery from exercise: There’s no “on-off” switch but rather a continuum of recovery that varies between slow-twitch endurance muscle fibers and fast-twitch power fibers. Also, no surprise, there is substantial individual variation. Read this column, and you’ll know more about the recovery process than you did before. Guaranteed. More at Outside Online. 


The carbs in your diet, or the lack thereof, can affect more than your endurance. Australian sports nutrition superstar Louise Burke has spent the last few years rigorously testing elite race walkers as they try different diets (mainly low-carb vs higher-carb) and then perform all-out time trials to see how the diets affect their performance. Here, she and colleagues did a 6-day diet comparison of the above, plus a group that consumed insufficient calories (Low Energy Availability). They looked primarily for “immune, inflammatory, and iron-regulatory responses to exercise in endurance athletes.” 


Conclusions: The low-carb, high fat diet “elicited small yet unfavorable iron, immune, and stress responses to exercise.” In contrast, 6 days of LEA produced “no substantial alterations to athlete health.” Therefore, “short-term restriction of carbohydrates, rather than energy, may have greater negative impacts on athlete health.” Note well: Burke and other sports nutrition experts are no fans of LEA. Here, they’re just reporting that a short 6-day restriction doesn’t seem to affect health the way longer term LEA has been shown to do. More at Medicine & Science in Sports & Exercise. 


Finally, carbs appear a minor factor when strength training, according to a systematic review of carbohydrate manipulation and strength performance. Result: “ Longer-term changes in performance were not influenced by carbohydrate intake in 15 studies; one study favored the higher- and one the lower-carbohydrate condition.” More at Nutrients. 


Top (free) marathon training plans--and non marathon too

The internet is bursting with free marathon training plans (and ones you have to pay for), but some deserve a bit more attention than others. Particularly when they bring a lot of plans together in one place, which allows you to select from a substantial menu.  


Runners World’s first senior writer, Hal Higdon, has long led the way in this department. Even though his programs are also available for $$$ at Training Peaks (with a few bells and whistles), Hal continues to offer them for free on his personal website. So far as I know, he was the first to do so--back in the Dark Ages pre-2000--and his programs have been followed successfully by thousands of runners. Here’s Hal’s basic Training Plan “menu” page. I counted quickly and found at least 50 different training plans. All free. 


Another high-quality source has now followed in Higdon’s footsteps. This is Marathon Handbook, which recently made all its plans free at this webpage. MH also excels at producing a vast number of free runner-advice articles on almost every topic you can imagine. 


SHORT STUFF you don’t want to miss 

>> Is milk better than water for rehydration? 

>> Good news. Your running economy improves with experience. Bad: It gets worse with age

>> Also good/bad: Women athletes gain sense of “power” from big events, but also feel “fear.” 


GREAT QUOTES make great training partners “You have power over your mind, not outside events.  Realize this, and you will find strength.”  – Marcus Aurelius 


That’s it for now. Thanks for reading. See you again in a week. Amby