Ever wonder if those heart rate zone calculators are really telling the whole story — especially as we get older? I did. So, as a runner in my 60s, I decided to stop guessing and booked a lactate threshold test at Body Insight Canada.
This wasn’t some specialized test for older runners — just a standard treadmill-based lactate threshold assessment. But for me, a Masters athlete looking to train smarter (not harder), it was exactly what I needed. The result? Clarity, a few surprises, and a big ol’ “told ya so” from my gut to the generic formulas I’d been using for years.
Why I Got a Lactate Threshold Test as a Masters Runner over 50
Like many runners over 50, I’ve spent plenty of time side-eyeing those one-size-fits-all heart rate formulas. “220 minus age”? That would put my max HR at 154 — a number my body laughed at around tempo pace. Even the training zone estimates from recent time trials didn’t fully sit right.
So, I went into the lab. I booked a treadmill-based lactate threshold test at Body Insight’s Toronto location. The setup was simple and low-stress:
- 5-minute stages, with speed increasing each time
- Blood lactate sampled via fingertip after every stage
- Heart rate tracked with a Polar chest strap
- RPE (Rate of Perceived Exertion) check-ins each round
💬 “At no point did I feel like I was about to crash and burn… even at the end.”
The Results: LT1, LT2, and a Reality Check
The test revealed two key thresholds:
| Threshold | HR (bpm) | Pace (min/km) | Lactate (mmol/L) |
| LT1 | 147 | 7:53 | 1.9 |
| LT2 | 163 | 6:35 | 3.9 |
Throughout the test, I secretly worried that the numbers would show I’d been pushing too hard on my easy runs. Instead, my Zone 2 range came in between 136–147 bpm — almost identical to the range I manually set in my Garmin months ago based on instinct and feel.
The formulas had been misleading. My gut? Turns out it was right all along.
Comparing with My Garmin Data
Out of curiosity, I wore my Forerunner 235 during the test. A few takeaways:
- Garmin overestimated my heart rate by around 10 bpm during the early-to-mid stages (minutes 9–18)
- At threshold effort (163 bpm), the lab data and Garmin nearly matched
- Trend lines aligned, even if the spikes didn’t
I’ll still rely on my chest strap for precision, especially on race days and intensity workouts. But it was reassuring to see that some of the tools I already use aren’t completely off the mark.
Key Takeaways
- Trust, but verify: Online calculators and default formulas are a decent starting point — but they won’t reflect your unique physiology.
- Your instincts matter: I had adjusted my heart rate zones based on perceived effort, which helped me train effectively for the Georgina Spring Fling Half Marathon. The test confirmed I was closer than I thought.
- There’s room to grow: Zone 2 looks solid. Now I’ll be sharpening my Tempo (148–155 bpm) and Threshold (156–165 bpm) efforts.
What’s Next?
With this data in hand, I’ll be dialing in more specific workouts during my marathon build — longer tempo runs, cruise intervals, and perhaps a few VO₂max teasers.
And yes, I’ll still be fueling with dates and staying on top of recovery. Aging pacefully means training smart and staying curious.
Final Thought
If you’re a runner over 50 wondering whether a lactate threshold test is worth it — I say go for it. The peace of mind, the precision, and the personal insights are well worth every drop of blood.