💡 Does Your Heart Say Go, But Your Muscles Say No?
“This ‘readiness score’ is bullsh*t!”
That was a friend and training partner lamenting how leaden her legs felt up the 3rd climb of the day despite her Oura ring readiness score telling her she was ready for action. This mismatch between app and reality happens all the time, and can become more common as we head into midlife…and one I experience regularly myself.
To understand why, it’s first important to understand what devices like the Oura ring (which I’ve used for years and find really helpful) can tell you–and what they can’t. Because often, people are using them like a traffic light, when they’re really just one number on the dashboard.
HRV Doesn’t Care About Your Legs
Devices like Oura ring measure various metrics, including sleep, resting heart rate, and heart rate variability to come up with a “readiness score”—generally thought of as how primed your body is to perform. Many active folks hone in on those heart rate metrics, like HRV in particular, as the primary signal of how recovered they are. HRV measures the variation in time between your heartbeats. It tells you your overall systemic stress and recovery balance. When it’s higher, that’s a sign you’ve bounced back well and you have better recovery and readiness, while lower HRV can signal stress or overtraining.
But while HRV is a proxy for global physiological stress, including mental, cardiovascular, and metabolic strain, it is not specific to the muscles.
HRV cannot reliably detect: local muscle fatigue or soreness, glycogen depletion in your muscles, or neuromuscular function decline (i.e. how well, or not, your muscles and nervous system are coordinating for strength and power output).
Simply put: your central nervous system and your muscles aren’t always operating on the same recovery time table. For instance, one study found that after an intense bout of resistance training, HRV returned to baseline within 24 hours and neuromuscular performance (jump power and barbell speed when lifting) mostly recovered by 48 hours, but perceived soreness and recovery remained suppressed at 48 hours. So again, while HRV is often used as a quick marker of recovery, it doesn’t reliably correlate with how recovered your muscles feel or how they perform.
With age, our muscles take longer to recover, which can also be more pronounced with menopause. Research shows that declining estrogen levels increase inflammation and can slow muscle recovery. In one study, postmenopausal women had a 20% longer recovery period compared to premenopausal women. Another found that postmenopausal women had CRP (a marker of inflammation) levels 35% higher than premenopausal women, which correlates with slower recovery and increased muscle soreness.
Simple Training Swaps for Mismatch Days
To train smart on days when your legs are lagging behind: keep moving,<> but reduce mechanical load, focusing on movement quality, blood flow, and recovery, rather than max output. A few strategies to try:
Active Recovery
Try light cycling, swimming, walking, and mobility work. It increases circulation, reduces soreness, and speeds recovery. Think 30 to 45 minutes of Zone 1 cardio plus 15 min mobility/yoga.
Technique & Skill Work
These can be good days for drills, form work, and low-load movement patterns, because you’re putting lower stress on your muscles while maintaining those neural pathways. Think swim stroke work or lifting form drills with just the bar or a PVC pipe.
Split Work
Do something that works the muscles that aren’t fatigued. If your legs are torched from a hard running session, you can do a decent upper body or core workout. That way you keep your training stimulus going without overloading tired areas
Avoid high-volume lifting, eccentric-heavy work, long runs or rides that overuse the same muscle groups, and high-fatigue sessions just because your HRV says 'go' (I've been guilty of that more times than I'd like to admit!).
Finally, days like these are a good time to remind yourself that data can be a helpful part of your training picture, but it’s really just a part. How you feel is always the best readiness indicator of all. Never lose sight of that no matter what your apps are telling you. |
