June 27, 2024

Below is the abridged version of my “Run Long, Run Healthy” newsletter for this week. You can SUBSCRIBE HERE to get the much longer and more complete, full-text edition. Thanks for reading. Amby 

4-Minute Magic--The Best Interval Workout

Two new papers look at a familiar and important question. 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?

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 took matched groups of male and female subjects, and trained them for 6 weeks to see who would improve performance the most. Each group did a specific training session 3 times a week during those 6 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 6 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 threshold pace (tempo pace). 

Subjects did 5 to 6 of these, with 3 minute recoveries between. 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. 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 more interval sessions? A Brazilian team investigated this question with a group of “well trained runners.”

Half the runners did 4 weeks of hard intervals while the other half did 4 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.

Fast Track To Strength Gains: Get Stronger In Less Time

I know there are plenty of high-fit athletes who really enjoy their time in the gym hefting weights. And I know we all need to do 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 4 sets of one exercise, followed by several minutes rest, then 4 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, then took several minutes rest. Both routines eventually completed sets on the same 6 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.

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

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 made up 50% of all ultra runners.

That’s an issue that 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, as well as 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 both 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 a lot less than 10%, and lends credence to the female-endurance hypothesis. For social-cultural reasons, women were slower than men to begin entering traditional road races, 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. 

SHORT STUFF You Don’t Want To Miss

>>> Build more bone: How to use cardio exercise, strength training, and balance to improve your bone health 

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 will power.

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