Zone 5 is the zone most people think they're training in — and rarely actually are. It sits at 90 to 100 percent of your maximum heart rate, at or above VO2max, and can be sustained for somewhere between 30 seconds and 2 minutes at true maximum intensity.

And it raises the ceiling for everything else. When Zone 5 develops, your Zone 4 starts to feel like Zone 3. Your threshold climbs. The entire spectrum shifts.

In this final episode of The Catalyst's heart rate zone series, Coach Chris explains what Zone 5 actually is, how to accumulate meaningful time at VO2max without burning out — and the one tactical insight most people miss.

That insight: Zone 5 requires your cardiovascular system to be the limiter, not your muscles. Heavy slow movements cause your legs to fail before your heart ever peaks. Rhythmic, sustained, large-muscle movements — running, rowing, cycling, hill sprints — allow the cardiovascular system to truly max out.

You'll also learn the Billat 30/30 protocol, developed by French physiologist Véronique Billat, which exploits the VO2 lag phenomenon to accumulate more time at VO2max than most athletes think is possible in a single session. And newer research on how to progress from 30/30s to longer intervals as fitness develops.

One session per week. Warmed up. With purpose. That's how you use your highest gear.

Book your free No-Sweat Intro at catalystgym.com/free-intro.

Everyone has an opinion on Ozempic right now — especially with a Canadian generic hitting the market. But after almost thirty years of coaching, here's what might surprise you: I'm not against it.

In this episode, I break down why GLP-1 medications like Ozempic aren't a moral failure to need, and aren't a magic fix either. I share the story of a client whose bariatric surgery completely changed how I think about medical weight-loss interventions, walk through what the research actually shows about muscle loss on these drugs, and lay out exactly what you need to do — starting the day you begin the medication — to protect your metabolism, your mitochondria, and your long-term fitness.

You'll learn why muscle loss is the hidden risk nobody talks about, what "zone two" training actually means, and why one hard workout a week matters more than you think.

Ozempic can be a legitimate first step. This episode covers what comes after.

Register for a free intro at catalystgym.com

Zone 4 hurts. Not in a vague, uncomfortable way — in a specific, accumulating, burning way. Lactate is building faster than you can clear it. Every second feels longer than it should.

And it is absolutely worth it.

In this episode, Coach Chris explains exactly what Zone 4 is, why it produces the most direct improvements to your lactate threshold, and how to actually get through it — physically and mentally.

The physiology first: the burning sensation in Zone 4 isn't caused by lactic acid itself. It's caused by hydrogen ion accumulation. Lactate is actually a useful fuel — your slow-twitch fibres burn it. Zone 4 training teaches your body to shuttle lactate from where it accumulates to where it gets burned, faster. The ceiling rises. What feels like Zone 4 today starts to feel like Zone 3.

The formats: the Norwegian 4×4 protocol — four intervals of 4 minutes at Zone 4, 3 minutes active recovery between — is one of the most researched structures in endurance science. Tabata-style intervals (20 seconds on, 10 seconds off) work for most people at Zone 4 to 5 intensity.

The mental game: dissociation — counting backward, the backward alphabet, chunking to landmarks — reduces perceived exertion and improves tolerance in ways research consistently supports. And a training partner produces a measurable physiological effect that makes Zone 4 efforts feel survivable in ways solo training simply cannot match.

Book your free No-Sweat Intro at catalystgym.com/free-intro.

Zone 3 has a reputation problem. Some coaches call it the grey zone — too hard for recovery, not hard enough for maximum stimulus. And when Zone 3 happens by accident, drifting up from what should have been a Zone 2 session, that criticism is fair.

But the athletes who dismiss Zone 3 entirely are missing one of the most time-efficient tools in training: sweet spot intervals, deliberately executed at the top of Zone 3 for extended durations.

In this episode, Coach Chris breaks down the crucial difference between grey zone grinding and intentional sweet spot training, and why that distinction changes everything.

At sweet spot intensity — the upper edge of Zone 3 into the very bottom of Zone 4 — your body can use lactate as a direct fuel source. You're training your Type IIa muscle fibres to become more aerobically efficient. And you can sustain this intensity for 20 to 60 minutes, creating extended adaptation time that Zone 4 intervals simply can't match.

You'll learn two formats that actually work: long sustained sweet spot intervals, starting at 2×20 minutes and building toward a single 60-minute effort, and over-under intervals — the structure used by athletes like Tadej Pogačar that alternates just below and just above threshold to train lactate clearance directly.

Plus: how often to do this, how to structure recovery around it, and the one mistake that turns a great sweet spot session into wasted fatigue.

Book your free No-Sweat Intro at catalystgym.com/free-intro.

Zone 2 training is the most talked-about topic in endurance and longevity science right now. But most people doing it aren't getting the full benefit — either they're working at the wrong intensity within the zone, missing key tactics, or skipping the pre-session prep that makes a real difference.

This episode is not about how to know if you're in Zone 2. It's entirely tactical — specific things you can do before, during, and after a session to get dramatically more out of the time you're already spending there.

Coach Chris covers four evidence-backed tactics. First: Zone 2 has a ceiling and a floor, and the research from Dr. Iñigo San Millán is clear that mitochondrial adaptation is strongest at the top of the zone, not the middle. Most people are training too conservatively. Second: nasal breathing is free real-time feedback for your intensity — and produces nitric oxide that improves oxygen delivery. Third: your diaphragm is a muscle, and warming it up with five minutes of deep belly breathing before your session delays respiratory fatigue and extends how long you can hold Zone 2 — the free version of what those Instagram breathing devices do. Fourth: session duration matters more than most people realize — 45 to 60-minute sessions produce meaningfully different mitochondrial adaptations than 20-minute sessions.

Plus: the case for occasional fasted Zone 2 training and why frequency compounds the adaptation faster than any single-session tactic.

Book your free No-Sweat Intro at catalystgym.com/free-intro.

METCONs changed fitness. CrossFit popularized them, and before that, training to complete exhaustion in a group setting was unusual. Now it's everywhere — and for good reason. Metabolic conditioning workouts are one of the fastest tools for improving VO2max, building cardiovascular fitness, and triggering real body composition change, especially for beginners.

But there's a problem. A lot of people are doing METCONs every single day and hitting a wall — weight loss stalled, strength plateaued, motivation tanked. This episode explains exactly why.

Coach Chris Cooper breaks down what METCONs actually do well (and the research is solid), then covers three things they can't do on their own: they don't train your body to burn fat efficiently, they hit a strength ceiling without progressive overload, and daily high-intensity training leads to physiological burnout — not boredom, burnout — that causes most people to quit.

The fix is the 80/20 principle: for every hard, high-intensity session, you need at least two zone 2 workouts — aerobic, conversational-pace training that builds your fat-burning base and lets your nervous system recover. Plus one dedicated strength session with progressive overload.

This isn't about balance or injury prevention. It's about performing better, changing your body composition, and staying in the game for years — not just weeks.

You'll get three specific prescriptions you can apply this week, whether you're brand new or stuck at a plateau.

Listen at catalystgym.com

Nearly half of all adults now own a fitness tracker. Most are using it to make real decisions — when to push, when to rest, whether to even show up today. The problem: some of the most important numbers on that screen are significantly less accurate than the device lets on.

In this episode, Coach Chris gives an honest breakdown of what wearables actually measure well — and where they quietly mislead you.

The good news first: heart rate during exercise is reasonably accurate, sleep duration tracking is useful, and long-term trend data over weeks and months is probably the most valuable thing these devices produce.

The bad news: calorie burn estimates are off by 30 to over 100 percent depending on the study. The Apple Watch has been shown to overestimate energy expenditure by as much as 115 percent. That number is the flashiest readout on your screen and also the least accurate.

And recovery scores built from HRV — the green/yellow/red readiness ratings on Whoop, Oura, and Apple Watch — are based on a noisy, highly individual signal that varies with hydration, alcohol, stress, sleep timing, and room temperature. Research shows a single morning's recovery score is a weak predictor of actual workout performance.

For anyone still building the fitness habit, letting a subscription algorithm decide whether to skip the gym is the wrong call.

You'll also get three evidence-based ways to actually use your tracker effectively.

Book your free No-Sweat Intro at catalystgym.com/free-intro.

When you first start exercising, the competition is you versus you. The heaviest weight you'll ever move is the front door.

But after about a year of consistent training, something shifts. You feel better. You're more confident. And it becomes dangerously easy to get complacent — right around the point where habits quietly start sliding backward.

In this episode, Coach Chris makes the case for signing up for a competition — not to win, but because doing it is the win.

You'll hear why the fear of competing is actually the point, not an obstacle to push through. Why benchmarking events like Catalyst's annual SuperMeet aren't tests you can fail, just honest data about where you stand. And why training alongside other people — what Chris calls "collaborative competition" — pushes you further than training alone ever could.

Whether it's your first 5k, a Hyrox race, the CrossFit Open, the ARCH Ride for hospice this August, or something like Xenom, the specific event matters less than choosing the right level of challenge: something 10 to 15 percent harder than anything you've done before, not the biggest thing you can find.

This episode is for anyone who's been training for a while and is wondering what comes next.

Talk to your coach at Catalyst about what's right for you.

Learn more at catalystgym.com.