March 2024

Spring came on quickly here in the Bay area, it’s hard to believe that just a few weeks ago the big news was a massive wave of storms and blizzards in the Sierras. It’s now so warm I feel like I better to hustle to fit in a few more days of skiing this season.

Food and GLP-1’s: one question that I’ve been curious about is how food selection changes with GLP-1 use and the associated reduction in overall calorie intake. Food provides nutrients as well as calories, and if you eliminate the most nutrient dense foods and keep the ones that offer calories only (i.e., “junk food”), you might lose weight but wind up with other issues. So I was pretty interested in two pieces of data that seemed to support the idea that GLP-1 users not only eat less, but eat better. But after looking at them closely, I’m not convinced. Morgan Stanley wrote a report which shows clearly that GLP-1 users make healthier food choices, however that report was based on self-reported data, a big reason to be skeptical (humans are notoriously bad at self-reporting). A market research company called Numerator also studied receipts from grocery stores, and their data showed that for at least two junk food categories (ice cream and snack food), receipts declined less than receipts for all food, suggesting that food choices don’t improve. It looks to me like this is an issue that needs more data, and perhaps more education of GLP-1 users about how to optimally adjust food intake.

New Calorify result: As I’ve transitioned away from cycling to focus almost exclusively on running, I wanted to do another test and see how things compared. Overall I got no surprises, my total energy expenditure dropped just a bit, from 3,284 to 3,118 per day. Interestingly my TSS went up, from 442 to 555 (on 35 miles of running, one bike ride and 3 moderate strength training sessions). My body fat crept up a bit to 14% (no surprise, I haven’t been very disciplined about diet) and my NEAT fell quite a bit (672 to 415 cal/day), meaning my PAL dropped a bit to 1.93 (3118/1613) even though exercise energy increased (559 to 729 cal/day). Given the muscle and skeletal stress of running, I actually feel more “beat up” than when I was at the higher PAL but training mostly on the bike last summer. This thread on X talked about this phenomenon of TSS and the stress of eccentric loading, and it’s part of why experts like Alan recommend lots of bike time for runners looking to improve metabolic fitness. If I had the time and energy, I’d still be doing long slow bike rides every week, but I’m in a bit of a crunch to build my running base, so I’m focusing almost exclusively there.

Two things I’ve also been working on is testing with a Stryd (a gift from my boss at Calorify, my boss knows me well…) and trying to resolve a flair up of IT band pain. In a month or two I’ll probably publish an ITB special edition like I did for my plantar fasciitis. I’ll also share some numbers and details on Stryd.

Classics season is off to a great start, with an amazing 80 km solo ride from Pogacar at Strade Bianche (and an equally decisive if less dominant win for Kopecky in the women’s race), then the narrowest of sprint wins for Jasper Philipsen at Milan-San Remo (Poga was third). This post on X harkens back to when grand tour contenders regularly competed for the classics wins. If you’re from my generation of cyclists you’ll recognize those two superstars, if you’re not, that’s Sean Kelly winning from Greg Lemond. It’s great to see those days return. I had forgotten Lemond made the podium at MSR (he also finished fourth in Paris-Roubaix in 1985).

Upcoming conferences: I’ll be at Obesity Medicine (Denver, late April), then back to the Bay area for Stanford Drug Discovery Symposium (April 29-30), and finally heading to Precision Clinical Trials (Boston, early May). That will keep me busy the next 6-7 weeks. If you’re at any of these events, be sure to stop by Calorify and say hello.

Just got a good deal on Saucony Ride 16’s, look forward to adding these to my rotation this week. I found them to run small, I had to size up ½ size from my usual in Saucony.

More about creatine, this time in concert with two of my other favorite things - nitric oxide and caffeine. BTW, does anyone else enjoy Stroop tests or is it just me?

Ski week 2024 - what at trip. Great weather, great snow, great company and great memories with the kids and their friends & family.