Cardiorespiratory fitness and longevity: what VO₂max predicts and how to raise it
How cardiorespiratory fitness is measured, how strongly it predicts mortality, where the largest risk reduction lies, and which training raises VO₂max.
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The Pulz8 Blog
Heart-rate training, hybrid athleticism, group-training culture and the science of effort, from the team building Pulz8.
Chest strap, armband or watch: how accurate heart-rate sensors are in the gym
How electrical and optical heart-rate sensors work, what validation studies show for running, cycling, strength and interval work, and how much sensor error matters for training zones.
Protein timing after training: how much the anabolic window matters
What happens in muscle after resistance training, what the protein-timing research shows, and how to set a daily protein target and spread it across meals.
How a warm-up works, and how to structure one for a group class
What a warm-up changes in the body, what the research shows for performance and injury, how long static stretches should be, and how heart rate behaves while you warm up.
How maximum heart rate shapes your training zones
Learn how maximum heart rate sets your zone boundaries, compare two common formulas, and see what your own readings can tell you.
Heart rate during strength training: what it can and cannot tell you
Why heart rate alone cannot measure the difficulty of a heavy set, how to interpret it between sets, and which measures help assess strength-training effort.
Cardiovascular drift: the role of heat, hydration and electrolytes
How heat and fluid loss affect heart rate during prolonged exercise, when sodium replacement is useful, and how to estimate sweat rate.
How quickly does your heart rate recover after exercise?
Your heart rate after an interval can help you track changes in fitness. Here's how to measure recovery and make sense of the numbers.
Coaching Mixed-Ability Groups with Heart-Rate Zones
How to use heart-rate zones to coach groups with different fitness levels, adapt intensity to each participant, and monitor effort on a shared dashboard.
How to set up live heart-rate zones in your gym
A practical Pulz8 setup guide for gyms: compatible devices, Bluetooth capacity, heart-rate zone settings and a first-week plan for coaches.
Pace the Race, Not the First Kilometer: Heart Rate for Hybrid Racing
Hybrid races like HYROX are mostly lost in the first fifteen minutes. How to use heart rate to pace eight runs and eight stations so the last kilometer is your fastest, not your slowest.
Caffeine Changes How Hard It Feels, Not How Hard It Is
Caffeine is one of the few supplements with solid evidence behind it. What it does to performance, what it does to your heart rate, and why the tile on the wall matters more after a pre-workout.
Your heart rate remembers last night: sleep, stress, and training readiness
Poor sleep, stress, and alcohol can affect your heart rate. Learn to spot changes from your usual pattern and decide when to ease off.
The Board Effect: Why a Shared Heart-Rate Screen Changes How a Class Trains
Group classes have always hidden the one thing that matters most: individual effort. Here's what happens, psychologically and physiologically, when that effort becomes visible to everyone in the room.
Creatine: The Most Boring, Best-Studied Supplement in the Gym
No proprietary blend, no marketing gloss — just one of the most researched compounds in sports science. Here's what creatine actually does, and doesn't.
The 80/20 Rule: Why Most of Your Training Should Feel Easy
Elite endurance athletes spend roughly 80% of their training time easy and 20% hard. Here's the science behind polarized training, and how it shows up on the board.
Know Your Zones: Zone 5 Is Red, Brief, and Non-Negotiable
Zone 5 Maximum is the shortest, most explosive heart-rate zone — and the easiest to misuse. Here's what it's actually for and why it belongs in minutes, not miles.
Know Your Zones: Zone 1 Is the Gray Tile Everyone Skips
Zone 1 Warm Up looks like doing nothing. It's the zone that decides whether the hard work you did yesterday actually becomes fitness.
Know Your Zones: Zone 4 Is Where Orange Starts Talking Back
Zone 4 Threshold is the hardest pace you can hold and still call sustainable. Here's why the orange tile is the single best predictor of race-day performance.
Know Your Zones: Zone 3 Is the Green You Have to Earn
Zone 3 Aerobic is where comfort ends and real training begins. Here's why the green tile is the most misunderstood — and most powerful — zone in the building.
Know Your Zones: Why Zone 2 Is the Base Every Athlete Is Built On
Zone 2 is the unglamorous blue tile that builds your aerobic engine. Here's what it is, why it matters, and how to actually find it on the screen.