This Surprising Workout Timing Was Linked to Higher VO2 Max, Per 800+ Participants
New research suggests that when you’re active might matter just as much as how you move, especially as you age.
According to a recent study published in Medicine & Science in Sports and Exercise, adults who consistently reached their peak activity earlier in the day had significantly better heart and lung function than those with later, more irregular movement patterns.
Even more intriguing? The research didn't just focus on gym time. All types of activity, from walking the dog to grocery shopping, counted.
The findings hint at a compelling takeaway: syncing your daily movement with your body’s internal clock could be a low-effort, high-impact strategy to support longevity.
Why timing may be everything
In this study, about 800 adults wore wrist devices for a full week to track their daily movement, everything from walking to gardening to simply resting.
The researchers weren’t just interested in how much people moved. They wanted to know when they were most active, how consistent their routines were, and how clearly their bodies cycled between activity and rest each day.
They focused on three key patterns:
- Activity strength (aka amplitude): How big the difference was between active times and rest times.
- Time of peak activity: When people were most active during the day.
- Daily rhythm consistency: How consistently someone hit their activity peak around the same time each day.
These patterns were then compared with markers of healthy aging, like heart and lung fitness and walking efficiency. The results? Timing did make a difference.
Earlier movers had stronger hearts & better endurance
Here’s what they found:
- People who were more active during the day and rested more fully at night had stronger heart and lung health, based on their VO2 peak (a key measure of fitness).
- Those who hit their “activity peak” earlier in the day (think: getting moving in the morning) also showed better cardiovascular health and moved more efficiently.
- When people followed a similar daily rhythm (getting active around the same time each day) they saw the same kinds of benefits.
Being consistently active earlier in the day was linked with stronger hearts and lungs, better endurance, and more efficient movement. These are critical markers of aging well and staying independent longer.
This study builds on a growing body of research suggesting that circadian alignment (the syncing of our behaviors with our biological clocks) plays a major role in everything from metabolism to muscle strength to mood.
What this means for your workout routine
First things first: the best time to work out is the time that works for you. If you love a lunchtime lift or a late-night yoga flow, keep doing what you’re doing. Movement at any time supports health.
But if you already lean toward morning workouts (or are trying to find a consistent routine), this study offers another reason to keep (or start) getting active earlier in the day. Morning movement may help reinforce your circadian rhythm, improve sleep quality, and boost motivation for healthier choices throughout the day.
And remember, this study didn’t just include gym sessions. The benefits extended to all kinds of movement: a brisk walk with a friend, puttering around the garden, vacuuming, or carrying groceries.
The takeaway
Your body doesn’t just care that you move; it also cares when. By aligning your daily activity with your circadian rhythm (especially by moving earlier and more consistently), you may help your body age more gracefully and efficiently.
That doesn’t mean you have to overhaul your schedule or become a 5 a.m. bootcamp devotee. Even a 20-minute morning walk, a few bodyweight exercises after breakfast, or stretching while your coffee brews can reinforce those healthy rhythms.