Read time: 3 minutes.

I was prepared.

I’d blocked out time in my calendar.

Packed my workout clothes in my bag.

But then it all derailed from there.

An important task took longer than expected. A meeting ran overtime. And another email just popped up: “Hey can you please do this 1 thing for me…”.

My exercise time was rapidly eroding.

So there’s no point, right? I’ll just carry on with my work. Exercise can wait. At least I might knock off another task on my never-ending list…

At this point we have a decision to make.

Is it worth "snacking" on a short bout of activity?

Or am I wasting my time if I can’t do a “full” session?

Not that kind of snack, of course...

For almost 30 years, exercise guidelines have told us we can accumulate the recommended amount of exercise for improving health in smaller “doses”.

But until recently, evidence to back up this claim was lacking.

A 2019 study combined the data from 19 relevant studies involving 1,080 participants.

Each of these studies compared two exercise interventions with the same intensity, type, and total duration.

One involved a single continuous bout of exercise bout per day, while the other accumulated the same amount of exercise in multiple bouts (of at least 10 minutes) per day.

The main outcomes in these studies were cardiorespiratory fitness, body fat percentage, and cardiovascular risk factors like blood pressure and blood lipids.

So does “snacking” on exercise actually work?

Turns out that for health benefits, it didn't matter how big the "bites" of exercise were.

Accumulated exercise had similar benefits to continuous exercise for:

• Improving cardiorespiratory (aerobic) fitness
• Reducing blood pressure
• Lowering blood lipids, insulin, and glucose

So doing the same amount of exercise either as a single continuous bout, or across multiple bouts throughout the day, had virutally the same health benefits.

But there was another interesting finding.

The analysis found accumulated exercise might even increase the benefits for certain health outcomes.

This included reducing body fat percentage, body mass, and LDL cholesterol.

OK, so what does this mean practically?

These findings support the idea that we can “snack” on shorter bouts of activity throughout the day, instead of needing to find larger chunks of time.

So while the health benefits of exercise are still linked to the amount of exercise performed, how we achieve this total “dose” is less important.

Having said that, it's important to remember even small doses of exercise have benefits.

And it doesn’t even have to be formal exercise either.

Take what we know about "VILPA" (or Vigorous Intermittent Lifestyle Physical Activity) for example.

VILPA is defined as “brief, vigorous bouts of incidental physical activities lasting 1 or 2 min that are done during activities of daily living, such as carrying shopping bags, carrying children, or walking uphill.”

One study found doing just 3 VILPA bouts per day (lasting ~1-2 min each) reduced:

• All-cause and cancer mortality risk by 38–40%
• Cardiovascular disease mortality risk by 48–49%

So even when the “ideal” amount of formal exercise isn’t possible, it’s still very much worth doing whatever is feasible.

What about resistance training for muscle growth or strength benefits?

I hear you say…

Turns out there's also evidence to support the “snacking” concept with resistance training.

One study had younger males do a resistance training program on 3 days per week.

In one group, participants did one longer session (3 sets per exercise) per day.

In another, this longer session was split into 3 smaller sessions (1 set per exercise) across the day.

After 12 weeks, the strength gains (one-repetition maximum bench press) were very similar:

• +51% for single bout
• +54% for triple bout

In other words, like what we see with aerobic-type exercise, splitting up resistance training into smaller chunks didn't compromise “gainz”.

Are smaller (but more frequent) exercise bouts easier to stick to?

A very important question.

Luckily the 2019 meta-analysis had this covered too.

They found continuous exercise did actually result in better adherence (more completed sessions relative to those prescribed).

But despite this, accumulated exercise led to more exercise being completed overall.

And the higher amount of completed sessions found with continuous exercise only applied to studies that prescribed 150 minutes of exercise per week, and not when less exercise was completed.

One downside of accumulated exercise was it was associated with higher dropout (20%) versus continuous exercise (16%).

The reason for this wasn't clear, but it's possible that for some people, exercising multiple times per day could be a barrier.

This clearly isn't a solution for everyone.

But where a longer continuous session isn't possible, at the very least, aiming for shorter exercise bouts could be a strategy to promote doing something rather than nothing.

Whether it’s true or not, lack of time is one of the most common reasons for not exercising.

Knowing large chunks of time aren’t needed to benefit from exercise could help people take action more often.

So if it’s more practical for you to split your exercise into multiple shorter sessions, you can be rest assured this probably won’t compromise the benefits.

Thanks for reading!

Until next week,

Jackson

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IMPORTANT:

The information contained herein is of general nature only and does not constitute personal advice. You should not act on any information without considering your personal needs, circumstances, and objectives. Any exercise program may result in injury. We recommend you obtain advice specific to your circumstances from an appropriate health professional before starting any exercise program.