The Rundown

Exercise & Inflammation. Research has long shown that moderate exercise has a beneficial impact on the body’s response to inflammation but what’s less understood is why. A new study out of York University says that the answers may be found at the production level of macrophages, or white blood cells responsible for killing infections and healing injuries.

Using a mouse model, the researchers showed that moderate intensity exercise trained the precursors of macrophages in bone marrow. Professor Ali Abdul-Sater explains, “The way that exercise is doing this is by changing the way those cells breathe, essentially, how they use oxygen to generate energy and then changing the way they access their DNA.”

The study found that these changes were potentially long term and Abdul-Sater expects the research would translate well to humans because this aspect of the immune system is generally very similar across mammals. The study’s next phase will collect immune cells from human volunteers who will do exercises of different intensities to find out which workoust are the best for balancing the inflammatory response.

“What this study suggests,” he says, “is that moderate and persistent exercise not only improves metabolic health but also will improve immune health in the long run.”

Hunger Games. Exercise can sometimes make you hungry but are you less likely to overeat if you pick the right workout? A new review of studies about eating and exercise says yes—if you choose a high-energy workout. (And bonus: It can even be short).

The central finding, as seen in an experiment published in April in the Journal of Applied Physiology, is that high intensity interval training, or HIIT, can reduce a key appetite-increasing hormone in many people.

The experiment had nine healthy middle-aged men and women workout in an exercise lab. On different days, they were assigned various workouts that included an easy run for 30 minutes, a minute of fast, intense treadmill running followed by a minute of rest, repeated ten times and a 15 second all-out bike interval, with two minutes of rest, repeated eight times.

Surprisingly, the interval training lead to quite a few of the volunteers losing some body fat despite it being too short to burn many calories. Checking the participants’ blood before and a few times after the workouts, the team discovered that lactate levels had sharply risen after the interval sessions.

The higher lactate levels correlated with lower amounts of acylated ghrelin. (Acylated ghrelin is one of the primary hormones that increases appetite). So, in the process of increasing their lactate, the volunteers lowered their ghrelin. A lead author of the study suggested that it’s likely the lactate partially blocked the release of acylated ghrelin from the stomach, where it normally starts, but this possibility would need to be confirmed.

The takeaway: If you want to keep your appetite in check after a workout, you might want to increase the intensity of the exercise. But you should also have reasonable expectations. The effects are likely to be short-term and require daily exercise, or at least several times a week. And most researchers agree that short, intense workouts will probably help with weight control (preventing weight gain) rather than weight loss.

Exercise, of course, has benefits well beyond appetite and weight. David Stensel, a co-author of the review who was not involved with the lactate study sums it up this way, “The most important role of exercise is keeping people sufficiently fit, healthy and active to remain engaged with family, friends and society and hence lead interesting and fulfilling lives.”

Extra Point

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The American Gladiators Documentary. Over its seven-season run, American Gladiators (1989-1996) became one of the most recognizable and beloved (or loathed) brands. This two-part documentary is part of ESPN’s 30 for 30 series but it’s not exactly a sports film. It’s more like amusing nostalgia. A lot of the film is director Ben Berman explaining how hard it is to make a documentary when his primary subject, Gladiator’s creator, Johnny Ferraro, is less than cooperative. But, it still manages to be entertaining and the available “gladiators” all tell candid stories about their time on the show. The American Gladiators Documentary is streaming on ESPN+.

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The Not Your Average Runner Podcast. In 2009, Jill Angie decided to stop thinking about running as a way to battle her weight and started using it as a tool to build strength and confidence. She quickly noticed that despite the vastness of the running community, there weren’t a lot of people in it who looked like her. Her podcast, which recently marked its 300th episode, is a celebration of running no matter your size or pace.

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Should I Worry About My VO2 Max? Journalist Joel Snape explains VO2 Max and how much it matters to your health in this article for The Guardian.