Most runners spend time tracking mileage on their shoes or their fastest splits, but few actually know their true energy needs. That’s where a Resting Metabolic Rate (RMR) test comes in.
The question is: when’s the best time to do it?
Here are the key situations when an RMR test can give you clarity, help improve performance, and prevent common fuelling mistakes.
Before Starting a Training Cycle
Marathon training? Half marathon build? Triathlon prep?
An RMR test at the start of your cycle gives you a baseline for fuelling. That way, you’ll know exactly how many calories to eat on training days vs rest days, and you can practice fuelling strategies long before race season arrives.
During Weight Management Efforts
If you’re trying to lose or maintain weight while running, RMR testing helps you do it safely. Online calculators can be off by hundreds of calories per day.
With your exact RMR number, you can:
- Set realistic calorie targets
- Avoid energy deficits that tank performance
- Reach body composition goals without risking fatigue or injury
One important point I want to make is I don’t recommend trying to lose weight during a training cycle for a race. If you have a weight loss goal, save that for the off season to ensure that you can perform at your best, and not be at risk for RED-S.
When Training Load or Goals Change
Maybe you’re ramping up mileage, adding strength training, or shifting from half marathons to ultras. Big changes in training = big changes in energy needs.
An RMR test ensures your fuelling keeps pace with your new demands, instead of leaving you under-fuelled and struggling to adapt.
If You Struggle with Fatigue, Plateaus, or Recovery
Feeling constantly drained, hitting a wall in training, or struggling to recover? Under-fuelling could be the culprit.
An RMR test helps identify whether your intake is matching your output. For many runners, eating enough to support their training can be the hardest part. Especially when they start to get up into the marathon and ultramarathon distances.
As Part of a Performance or Health Assessment
RMR testing pairs perfectly with other performance metrics like VO₂ max or sweat sodium testing. Together, they give you a full picture of your physiology:
- VO₂ max: aerobic fitness + training zones
- Sweat sodium: hydration + fuelling plan
- RMR: energy needs + nutrition framework
This integrated data lets you train smarter, recover faster, and race with confidence.
How Often Should You Get Tested?
The good news: your RMR doesn’t change dramatically overnight. For most runners, testing once provides data you can use for years.
That said, you may want to retest if:
- You’ve had a major body composition change
- You’ve shifted into a significantly different training load
- You’re hitting unexplained fatigue or performance plateaus
- You’ve been started on medications that affect your metabolism
Otherwise, one test can be enough to guide your fuelling long-term.
Related: What Does RMR Testing Tell You?
Key Takeaways
The best times to get an RMR test are:
- Before a new training cycle
- During weight management goals
- When your training load or goals change
- If you’re struggling with fatigue or recovery
- As part of a comprehensive performance assessment
- After starting or changing medications that affect your metabolism
Knowing your RMR gives you confidence that your fuelling matches your training, instead of leaving results up to guesswork.
Ready to Fuel Smarter?
Stop guessing. Book your Resting Metabolic Rate test in Port Moody today and leave with a personalized plan for training, recovery, and long-term performance.
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