"Activity Snacks" for Metabolic Control: 15 Squats Outperform Walking in Interrupting Sedentary Time

#1

If you work at a desk with a computer, keep this in mind! This a 2021 study, so you may have heard this already, but I needed the reminder so I thought others here might also:

A new study from the University of Toronto provides a compelling, zero-cost intervention for the sedentary longevity enthusiast: “activity snacks.” In a randomized crossover trial involving 14 healthy adults, researchers demonstrated that performing just 15 chair squats (with calf raises) every 30 minutes significantly improved postprandial insulin handling, outperforming even moderate walking breaks in duration of effect.

The Study Summary

Sedentary behavior is an independent mortality risk factor, distinct from a lack of exercise. To test practical interruptions, researchers subjected 14 participants (7 males, 7 females; age 24 ± 5) to three 7.5-hour experimental conditions:

  1. SIT: Uninterrupted sitting.
  2. WALK: 2 minutes of walking (3.1 mph) every 30 minutes.
  3. SQUAT: 15 chair stands with calf raises (taking ~1 minute) every 30 minutes.

While glucose levels remained similar across groups, insulin dynamics shifted dramatically. Following a mixed-macronutrient lunch, the SQUAT protocol reduced the incremental area under the curve (iAUC) for insulin by **37%**compared to sitting, whereas walking reduced it by 29%. Crucially, the SQUAT protocol sustained this reduction over a 3-hour period (24% reduction vs. SIT), while the walking group’s benefit lost statistical significance over the longer window.

Mechanistic Analysis for the Biohacker

  • The “Silent” Mechanism: Surprisingly, muscle biopsies revealed no significant changes in the phosphorylation of key insulin signaling proteins (AKTThr308, AKTSer473, AS160Ser318). This suggests the glycemic benefit is not driven by upregulating the classic insulin signaling cascade (sensitizing the pathway). Instead, the benefit is likely driven by contraction-mediated glucose uptake (non-insulin dependent GLUT4 translocation) or hemodynamic changes increasing muscle perfusion.
  • Metabolic Flexibility: The reduced insulin-to-glucose ratio in the SQUAT group indicates the pancreas required significantly less insulin to manage the same glucose load. Preserving pancreatic beta-cell function and maintaining low circulating insulin is a cornerstone of longevity strategies (antagonistic to pro-aging mTOR hyperactivation).
  • Hemodynamic Shear: The inclusion of the “calf raise” in the squat protocol likely enhanced the “muscle pump” effect, aiding venous return and potentially increasing shear stress on endothelial cells, a stimulus for nitric oxide production and vascular health.

Actionable Insights for N=1 Experimentation

  • The “30-30-15” Protocol: Set a repeating timer for 30 minutes during sedentary work. Perform 15 bodyweight squats with a calf raise at the top of each movement.
    • Feasibility: Highly feasible. Requires no equipment and less than 60 seconds.
  • Stacking Hypothesis: Combine this with a standing desk. While the study tested sitting interruptions, performing the squats while using a standing desk could theoretically amplify the non-exercise activity thermogenesis (NEAT).
  • Biomarker Tracking:
    • CGM (Continuous Glucose Monitor): Monitor post-prandial spikes. The goal is a flatter curve with less “area under the curve.”
    • Fasting Insulin: Over a month of this protocol, test if fasting insulin trends downward, indicating reduced basal resistance.
  • Dosing: The study suggests frequency beats duration. 1 minute every 30 minutes appears superior to longer bouts less frequently.
  • Limitations for Implementation: This specific protocol used healthy young adults. Older individuals with sarcopenia may see greater relative benefit due to the resistance component, or less if anabolic resistance is high.

Source Research Paper (open access): Interrupting prolonged sitting with repeated chair stands or short walks reduces postprandial insulinemia in healthy adults

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#2

I do this. I squat throughout the day. However, there are some other limitations. For older people (late 60’s onward), you may not be able to sustain such a volume of squats if you also do weighted squats as exercise (f.ex. I do 32 minutes twice a week - so 64 minutes - of very strenuous weighted squats including jumping squats). The volume becomes an issue with recovery and potential of overuse injuries.

Furthermore, and perhaps even more importantly, your base conditioning level matters. For someone like myself, who squats a lot, my squat endurance and efficiency is very high. A mere 15 air squats (bodyweight) even full ATG (“ass to grass”) translates to near zero effort. I don’t believe my body would even register it and translate into any kind of metabolic effect. So I do 2 minutes of jumping squats but without the weightvest - that definitely registers! And for my regular exercise jumping squats with a 45lbs weightvest for 5 minutes non-stop are extremely challenging. Anyhow, my point here is that you need to take into account your base conditioning and adjust accordingly.

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#3

I would imagine that walking lunges would accomplish the same thing and might be more functional.

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#4

BBC Chimes in…

From running up stairs, to rigorous gardening: these everyday activities could boost your health and help you live longer.

Everyone knows that the key to a healthy long life is to exercise and eat well. But what if you simply don’t have the time to slog it out at the gym, or chalk up 10,000 steps a day? The good news is that doing everyday activities with more rigour and energy can achieve huge benefits. Think running up the stairs, power walking around the house, or playing with your children or pets.

If you’ve followed exercise science in the last three years, you might have encountered a new term: vigorous intermittent lifestyle physical activity or VILPA. Also described through the various monikers of “exercise snacking,” “snacktivity,” or “activity microbursts,” it’s the latest solution to a long-term problem – how best to coax the most reluctant of exercisers to sit less and move more?

In the past decade, high-intensity interval training (HIIT) – which involves pushing the body to its limits through brief explosive bursts of running, cycling and bodyweight exercises like squats or jumping jacks – has become a popular workout for more time-pressed gym goers. It has also been shown to improve blood sugar control, cholesterol, blood pressure and body fat.

According to Mark Hamer, professor of sport and exercise medicine at University College London, VILPA is a scaled down form of HIIT. It simply means doing everyday activities with slightly more gusto with the aim of raising your heart rate for one or two minutes at a time.

Hamer explains that the idea of VILPA first arose when he and his colleagues were analysing movement data collected by fitting wrist worn wearables to people who did no formal exercise. The scientists noticed that, despite not playing sport or hitting the gym, some individuals were managing considerable amounts of movement simply by going about their daily lives. This ranged from fast bursts of walking while commuting to work, to going up stairs. “Much of this movement was accrued in very short chunks,” says Hamer. “This led to this concept of microbursts.”

…

Simple actions such as running up a flight of stairs can lead to significant health benefits (Credit: Getty Images)

To their surprise, Hamer and colleagues discovered that these microbursts of movement were linked to health benefits. In a 2022 study, using data from 25,241 people across the UK, Hamer and scientists at the University of Sydney found that just three or four one-minute bouts of VILPA each day was sufficient to provide a 40% reduction in the risk of premature death from all causes, and a 49% reduction in risk of death from cardiovascular disease, compared with people who did little movement at all. A more recent study also concluded that just over four minutes of VILPA each day can offset some of the risks of a sedentary lifestyle for heart health.

“Through doing their daily activities in brief bursts of higher intensity, several times throughout the day, people can still attain health benefits to lower their risk of chronic diseases,” says Matthew Ahmadi, a postdoctoral research fellow at the University of Sydney. “It [VILPA] can also help stave off frailty which becomes very important as we age.”

When it comes to physical activity, doing anything is better than nothing.
…

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#5

CronosTempi,

You do jumping squats with a 45 pound weight vest for 5 minutes non-stop! Wow! How many can you do in 5 minutes and how far can you jump off the floor? I’ve never thought about doing something like that. However, it sounds more beneficial than the exercise I’ve seen on video of people jumping up onto a platform a foot or more above floor level. Safer, too.

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#6

Well, actually not that many - only some 15 squats a minute. The reason is because it’s a combination jump squat. As follows: after the jump, land on very slightly bent legs - this to allow for bone shock to ripple through, which is very beneficial for bone growth/density. Once I land, I then descend into the squat slowly - this is the eccentric movement in a squat (coming out of the squat is concentric). Eccentric movements when done slowly result in a stronger hypertrophy signal allowing better muscle growth. This increases time under tension - many people tend to “collapse” passively down into the squat thus losing a lot of muscle tension - going down slowly keeps the burn/tension longer. Then explode up into the jump, how high is up to you, because you give it your all - for me it’s not super high, maybe about a foot or so. Even though it’s not many squats per minute, because it’s almost always under tension due to the slow eccentric, you are working nonstop for the entire 5 minutes, rather than like most who squat, who only work the muscles about 50% of the time (collapsing on the way down). Also I only breathe through the nose. I can promise you, the 5 minutes is at the absolute limit of my abilities, and leaves a pool of sweat on the mat around me - there is a strong cardio element as my heart is pounding and I breathe through my nose with great difficulty (I desperately want to open my mouth to gasp for air).

Anyhow that 5 minutes is one interval in the 32 minute squat session I do twice a week. Extremely challenging, but I feel it gives me a total workout: bone, muscle (all three elements: strength, plyo/power, endurance), tendon, cardio, balance.

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