Mandate #17: Indulge in Intensity.

Don’t lose the surge.

There is a giant slice of your best life that most adults don’t realize they’ve lost: the ability to sprint.

By 30, many people haven’t sprinted in years. By 40, it can feel completely foreign.

Here’s the crux: certain adaptations, capacities, and levels of aliveness only exist behind the door of intensity.

The ​Canadian Physical Activity Guidelines​ and their American counterparts recommend roughly 150 minutes per week of moderate-intensity activity. It’s an important guideline that lowers risk and helps prevent decline.

But baseline health and full capacity are not the same thing. Moderate movement may maintain health, but intensity unlocks capacities that otherwise remain dormant.

For a long time, I lived mostly in the middle. I moved consistently and was active, but I rarely crossed into true intensity unless something forced it. The Barrhead 5k “Fun Run” was about as intense as I got.

When I began adding short, deliberate bouts of hard effort (even when they were under twenty minutes) I transformed.

• My body composition improved.
• My performance improved.
• My tolerance for discomfort and anxiety widened.

CrossFit happened to be the container where I learned this, but the lesson wasn’t about the method.

Here’s what the research says about intensity (it’s great news!):

• Minute for minute, vigorous exercise appears to deliver four to nine times greater reduction in disease riskcompared to moderate activity.
• VO₂ max, one of the strongest predictors of longevity and independence, often does not improve with moderate training alone. Nearly 40% of people who meet guideline recommendations never improve it. Intensity changes that.
• Short, intense efforts also improve executive function, insulin sensitivity, and energy regulation. The list of benefits is long.

Back to sprinting:

While many people see marathons or endurance races as the ultimate display of fitness, those who understand human performance are more impressed by your 1-mile time.

Humans are built for bursts. We have a unique energy system designed for short, powerful output. It once helped us chase prey and escape danger.

Like any ability, the capacity to produce force quickly fades when unused.

Even if injury has taken sprinting off the table for now, make it a long-term goal to reopen that door. Regain access to full output in some form. If running aggravates something, there are other ways in.

Assault bikes are one of my favorite tools. They allow maximal effort with minimal joint impact. Swimming is fantastic for breathless intensity without pounding. Rowing machines are also safe options for many.

The tool matters less than the stimulus. Running sprints are a worthy long-term goal, but what matters most is occasionally asking your system to produce everything it has.

And yes…intensity is hard and uncomfortable. But that’s a feature not a bug.

When effort climbs high enough, your heart must pump more efficiently. Your muscles must tolerate force and fatigue. Your nervous system must stay engaged when quitting would be easier.

That capacity carries over:

• It shows up when you keep up with your kids instead of sitting out. 
• When something physical pops up unexpectedly and you respond without hesitation. 
• When life applies pressure and you don’t shrink from it.

Intense exercise is even used clinically in the treatment of panic disorder, helping people learn that a racing heart is not a threat. It’s fascinating stuff.

People who regularly practice controlled intensity don’t just get fitter. They become the kind of people who can step into challenge when it arrives. 

They don’t sit out by default or wither under pressure because they’ve been here before. It comes from practice.

Intensity is powerful but doesn’t need to dominate your week. Once or twice per week is enough for most healthy adults training for capacity and longevity. The rest can be moderate, sustainable, restorative.

But if you never cross that threshold, certain doors remain closed. Doors in your physiology and doors in your character.

How to Try It: Keep it simple. Use the machine of your choice, or old-fashioned sprinting (if you are trained for it).

10-Minute Sprint EMOM

Every minute for 10 minutes: • 10 seconds hard effort • Recover for the remainder

Or:

30 Seconds On / 30 Seconds Off

For 10 minutes: • 30 seconds fast movement • 30 seconds full rest

Here’s my call to action: Indulge in intensity. Remain capable of surge, physically and mentally, when life asks for it.