David Mc Gettigan

Dad. Husband. Educator. BSc. Sports Rehab. Passionate about helping those with chronic pain. Neuroscience geek 🤓 Work: @biggerthanpain #mufc 🇮🇪☀️

[Matthew Zirwas, MD @MattZirwas]

Dermatology is wrong about the sun.

And it's killing people.

I'm a dermatologist. 226 publications. I should know.

Avoiding the sun increases the risk of dying as much as being a smoker.

We can fix it.

For decades, dermatology's message has been simple: avoid the sun. Wear sunscreen. Seek shade. UV causes skin cancer. End of discussion.

That message is incomplete and outdated.

People are dying because of it. Lots of people.

The evidence has gotten strong enough that the field needs to update it.🧵

[Adam @AdamJoseph]

Bruno Fernandes officially becomes the third player in Manchester United history with 100+ goals & 100+ assists in all competitions (105 & 100). He did it in 318 appearances.

For context; Leo Messi did it in 319 for Barcelona, Cristiano Ronaldo did it in 325 for Real Madrid.

[David Mc Gettigan @Daithi__Mac]

@ErwanLeCorre Yes you’re right! I had only checked in dark mode. Always plenty of things to tweak. Building an app myself at the moment 🫡

[Brett Cooper @imbrettcooper]

husbands everywhere this morning

[Howard Luks MD @hjluks]

Yesterday’s post about heart rate and base building triggered a number of responses from experienced runners saying, “But I run at 145+ HR, and I’m fine.” That reaction actually highlights how poorly understood the distinction between cardiovascular fitness and aerobic fitness still is, even among dedicated endurance athletes.

Let's explore this a bit...

Most runners run too fast on their slow days and too slow on their fast days.

Cardiovascular fitness refers to the delivery system. It reflects how effectively the heart pumps, how well blood flow is distributed, and how efficiently oxygen is transported to working tissues. Aerobic fitness, however, is primarily about utilization. It reflects how well the muscles use the oxygen delivered through oxidative metabolism, including mitochondrial function, fat oxidation capacity, lactate handling, and overall metabolic efficiency. These are related systems, but they are not interchangeable, and one can be well developed without the other being optimized.

It is entirely possible to have strong cardiovascular fitness and still operate with relatively high metabolic cost during steady-state efforts. This is particularly common among recreational runners and even among experienced non-elite endurance athletes who have spent years training at moderate intensities. They are durable, consistent, and capable, but their “easy” work often occurs at a higher fraction of their physiological capacity than they realize.

When an athlete reports that their easy runs consistently sit in the mid-140s (above 75% of maxHR), it does not reflect poor fitness. In many cases, it reflects a well-trained cardiovascular system paired with a habitual training intensity that sits near or above the first lactate threshold. The effort may feel subjectively easy due to years of adaptation, but metabolically, it is not truly low-intensity work. The body relies more on glycolytic pathways than on oxidative metabolism, even during easy runs.

This matters because the full development of the aerobic system is driven by sustained training below the first lactate threshold. While higher intensities absolutely stimulate mitochondrial biogenesis, the adaptations associated with metabolic efficiency—improved fat oxidation, expanded capillary density, lower lactate production at submaximal workloads, and reduced sympathetic strain—are most robust when a significant portion of training occurs at genuinely low intensities. In other words, intensity can build fitness, but extensive low-intensity volume refines efficiency.

When most training time is spent at or above LT1, athletes often become very good at tolerating moderate metabolic stress rather than minimizing the cost of aerobic work.

At elevated hr intensity, oxidative stress per session is higher, sympathetic activation remains elevated, and the recovery burden accumulates over time, even if the athlete feels subjectively comfortable. RPE can remain low while physiological strain remains moderate, particularly in experienced runners who have adapted psychologically to that level of effort.

In my office, it is clear that there is also a practical clinical layer that becomes increasingly relevant in midlife. The cardiovascular system adapts relatively quickly to the stress of training. Connective tissues—tendons, fascia, cartilage, and bone—adapt much more slowly. When moderate-to-high metabolic load is layered onto repetitive impact before true aerobic efficiency and tissue resilience are established, the total recovery demand rises. This pattern is reflected in the training errors I see routinely in clinic: Achilles pain, plantar fasciitis, patellofemoral symptoms, and lateral hip or gluteal tendinopathy. They are usually mismatches between the distribution of training intensity and our recovery capacity. This changes with age... and it will catch up to you.

None of this means that running at higher heart rates is inherently harmful, nor does it suggest that intensity should be avoided. Threshold work, tempo runs, and even high-heart-rate sessions are valuable tools. The issue is distribution. If most weekly mileage is performed at a moderate metabolic intensity, the athlete maintains cardiovascular fitness but sacrifices some metabolic flexibility and efficiency. Easy days are no longer truly low-cost, and recovery between harder sessions is less complete.

What is often given up is range. An athlete with a well-developed aerobic base can run at a lower heart rate for the same pace, oxidize more fat, produce less lactate at submaximal intensities, and accumulate more total training volume with less physiological strain. Their easy runs are genuinely easy at a metabolic level, allowing higher-quality work when intensity is introduced. They are not just fit; they are efficient and durable.

Base training, therefore, is not about avoiding effort or running unnecessarily slowly. It is about lowering the physiological cost of work so that training becomes more repeatable, recovery becomes more predictable, and long-term durability improves. The heart remains strong, performance is preserved, and the metabolic system becomes more efficient. For lifelong runners, especially after forty, efficiency and recovery capacity often become the true limiting factors rather than motivation or discipline.

[Matt Shumer @mattshumer_]

https://t.co/ivXRKXJvQg

[Jay Alto @theJayAlto]

you pity the moth confusing a lamp for the moon, yet here you are confusing a screen for the world

[Alan Couzens @Alan_Couzens]

“The majority of joint and tendon pain that I see in adults is just another manifestation of metabolic disease.” - @hjluks

A real pleasure for @inaki_delaparra and me to sit down with the Doc to discuss what actually drives health, performance, and longevity.

Whether your goal is elite performance or moving well at 100…

It all starts with metabolic health.

Full podcast 👇

[Ste Howson @MrStephenHowson]

I wanna go on the piss with Dorgie Best

[spochadóir @spochadoir]

how young fellas in Longford wave at each other from a passat full of green diesel

[The Figen @TheFigen_]

This artist plays one of Vivaldi's most difficult pieces on his accordion, a work that is normally performed by a whole orchestra.

[cinesthetic. @TheCinesthetic]

Andy Serkis recording The Lord of the Rings audiobook, casually shifting into pure unhinged brilliance about 25 seconds in.

[Brian Roemmele @BrianRoemmele]

Wow!

“We backed up Spotify (metadata and music files). It’s distributed in bulk torrents (~300TB), grouped by popularity.

This release is the largest publicly available music metadata database with 256 million tracks and 186 million unique ISRCs”

Link: https://t.co/4lGzZXA1BM

[Sergey Karayev @sergeykarayev]

This robot solving a rubiks cube in 0.103 seconds is a little preview of what "AGI" really means

[Off The Ball @offtheball]

"I do believe it's definitely deserved"

Kieran Hughes reacts to @Scotstowngaa 's Ulster Senior Club Football Championship win over Kilcoo in Armagh

[Cahair O'Kane @CahairOKane1]

This stuff is so far out of my comfort zone that I can’t even see the comfort zone from here. But a quick video recap of Scotstown’s win yesterday

[Ulster GAA @UlsterGAA]

36 years in the making 🏆

#UlsterClub2025 #ClubMeansMore

@ScotstownGAA

[RTÉ Sport @RTEsport]

You have watched The Moment nearly 30 million times already, why not watch it once or twice more, in super slow motion

#coybig #troyparrott

[Ireland Football ⚽️🇮🇪 @IrelandFootball]

Troy Parrott, take your place on the pantheon of Irish greats 🇮🇪