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4-Minute Magic: The Best Interval Workout

+ The fast track to strength gains

4-Minute Magic: The Best Interval Workout 1

Here’s the free but abridged version of the Run Long, Run Healthy newsletter. See the links below to subscribe to the full-text edition with more articles and deeper, more specific running advice. – Amby


4-Minute Magic: The Best Interval Workout

4-Minute Magic: The Best Interval Workout 2

You’ve trained yourself into good shape. You’ve got 4 to 6 weeks remaining before a big race.

Now what? What should you do to boost your fitness and performance potential in those remaining weeks?

Two new papers look at this familiar and important question.

Here’s the payoff first, with supporting details to follow. The best way to improve your VO2 max and sub-max threshold is probably with 4-minute intervals run at about your 10K race pace.

Longer, slower intervals don’t provide enough stimulus. Faster intervals don’t last long enough.

That’s the conclusion reached by a research team that matched groups of male and female subjects and trained them for six weeks to see who would improve performance the most. Each group did a specific training session three times a week during those six weeks. The sessions ranged from “moderate” to several of “heavy” intensity to outright “sprinting.”

The “workout loads” were also matched. In other words, the slower your intervals, the more total time you had to run. The faster your intervals, the fewer minutes you ran.

Result: The moderate training group made essentially no gains in six weeks. If you keep doing the same training you’ve been doing, you won’t get fitter.

Also, running a bunch of 30-second “sprints” was suboptimal at improving VO2 max and lactate threshold. The winning workout consisted of 4-minute intervals run 10 percent faster than your threshold pace (tempo pace).

Subjects did five to six of these, with 3-minute recoveries between each one. The researchers noted that this type of effort produced good results for almost all subjects. They even argued that it should be adopted by cardiac rehab programs since the lower intensity training of such programs doesn’t improve fitness very much.

Previous studies have also found that 4-minute intervals appear to be the right length for improving VO2 max. Read more at ​Medicine & Science in Sports and Exercise,​ with free full text.

But could you get even better results with more strength training rather than interval sessions? A Brazilian team investigated this question with a group of “well-trained runners.”

Half the runners did four weeks of hard intervals, while the other half did four weeks of heavy/explosive resistance (strength) training.

Result: The interval training improved 1500-meter times by about 2.4%, and the resistance training improved 5000-meter times by 1.6% -1.7 %.

Conclusion: “Both resistance training and high intensity [interval training] constitute an alternative for training periodization.” More at ​J of Sports Sciences.​

RELATED ARTICLE: Periodization: Our Expert Training Guide On How To Plan Your Training Season


Fast Track To Strength Gains: Get Stronger In Less Time

4-Minute Magic: The Best Interval Workout 3

I know plenty of high-fit athletes who really enjoy hefting weights in the gym. And I know we all need regular resistance (strength) training.

But there must be many folks like me who want the shortest, simplest program to get their strength work done. That way we can return quickly to our preferred cardio training. Several new papers provide helpful guidance.

The first, a not-yet-published preprint, compared the effects of traditional strength training vs super-set strength training. The traditional routine involved four sets of one exercise, followed by several minutes of rest, and then four sets of the next exercise.

When doing super-sets, subjects did one set of the first exercise, followed immediately by one set of the second, and then took several minutes of rest. Both routines eventually completed sets of the same six popular strength exercises.

Result: Strength grains were equal both ways, but the super-sets took 36% less time overall to complete the full routine. Thus, “supersets appear to be a time-efficient alternative for eliciting muscular adaptations.” More at ​Sport RXiv​ with free full text.

The next paper, a systematic review and meta-analysis, compared traditional strength training to “drop set” training. When performing drop sets, the subject lifts a weight to volitional failure once, then slightly decreases the weight and lifts to failure again.

Result: Muscle gains were equal with both forms of strength training, but drop sets took 33% to 50% less total time. Thus, “Drop sets present an efficient strategy for maximizing skeletal muscle hypertrophy.” More at ​Sports Medicine Open​ with free full text.

RELATED ARTICLE: What Is A Drop Set? How To Promote Muscle Gain With Drop Sets


The Sex Debate: Who’s Better In Ultra Endurance Races?

4-Minute Magic: The Best Interval Workout 4

The sexiest question in running is literally the sex question. Are females catching males in endurance performance, particularly in ultra-endurance?

The discussion was first broached in a 1992 “Scientific Correspondence” in ​Nature​ (with free full text.) The authors pulled together a few data points to show that women marathoners would likely catch their male counterparts in 1998 and soon surpass them.

Well, no, that didn’t happen. But a lot has changed in running, particularly women’s running, over the last 30 years. So, where does the male-female sex difference stand in 2024?

If we look at the sex difference between the current world marathon records (2:00:35 and 2:11:53), we see that it stands at 9.4%. That’s close to the 10% gap that has long separated male runners from female runners.

However, these real-world comparisons face a significant problem: There are far fewer women than men in ultra races, usually just 10 to 30% of the total field. This tilts the scales of fairness, so to speak. Things might be different if females comprised 50% of all ultra runners.

That’s an issue researcher and ultra-runner Nick Tiller tried to answer in a recent journal paper and online article. Tiller’s a “skeptical scientist” and ​book author​ and a columnist at Ultrarunning Magazine, so his ideas carry substantial weight.

Tiller began by digging into ultra-running race results until he found two events with essentially equal numbers of male and female finishers. His subsequent analysis produced an academic paper at ​Applied Physiology, Nutrition, and Metabolism​ and a lengthy column titled ​“Are Women Closing The Gap?” at Ultrarunning.​

What did Tiller find? In a 50-mile race, there was no significant overall finish-time difference between the sexes, but the top 10 males were much faster than the top 10 females.

In a longer race,100 miles, there were no significant differences in either analysis: overall or top-10.

Conclusion: “The sex-based performance discrepancy shrinks to 1-3% in ultramarathons when males and females compete in comparable numbers.”

If that number holds up, it’s much less than 10%, which lends credence to the female-endurance hypothesis. For social-cultural reasons, women were slower than men to begin entering traditional road races, from 5K to marathon. But now they have mostly caught up.

The ultra world lagged still farther behind. It was once seen as the province of strong, testosterone-driven men. That, too, is changing rapidly. As the change accelerates, we’ll learn more about the sexy subject of sex and endurance performance.

RELATED ARTICLE: Women And Ultrarunning: Why Women Make Awesome Ultra Runners


SHORT STUFF You Don’t Want To Miss

HERE’S WHAT ELSE YOU WOULD HAVE RECEIVED this week if you were a subscriber to the complete, full-text edition of “Run Long, Run Healthy.”

Why not give it a try? SUBSCRIBE HERE.

  • Super shoe secrets: How to find the best super shoe for you • Don’t get bushwhacked by these running myths
  • How CPR saved a veteran marathoner’s life
  • Healthy (Exercising) Pregnant Mother = Obesity-Proof Baby
  • The Step-Up Solution: Build More Speed & Hill-Running Power
  • Back on track: How to limit low back pain while running
  • The making of champions: Roger Federer and Katie Ledecky
  • A great quote from Mahatma Gandhi on the importance of willpower.

DON’T FORGET: I spend hours searching the Internet for the best, most authoritative new running articles, so you can review them in minutes.

That’s all for now. Thanks for reading. RLRH will not be published next week. You’ll receive your next newsletter on July 11, 2024. Amby

Photo of author
Amby Burfoot stands as a titan in the running world. Crowned the Boston Marathon champion in 1968, he became the first collegian to win this prestigious event and the first American to claim the title since John Kelley in 1957. As well as a stellar racing career, Amby channeled his passion for running into journalism. He joined Runner’s World magazine in 1978, rising to the position of Editor-in-Chief and then serving as its Editor-at-Large. As well as being the author of several books on running, he regularly contributes articles to the major publications, and curates his weekly Run Long, Run Healthy Newsletter.

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