Lift when you will actually show up. That is the practical takeaway from a new randomized trial in adults aged 60 to 80: training at each person’s personal best time of day did not build more strength or muscle than training at their worst time of day.[1]
The idea made sense on paper. Your body runs on a circadian rhythm, a roughly 24-hour internal clock, and strength shifts across the day. So why not schedule workouts for your peak? This trial put that to a direct test.
What the trial tested
Researchers in Basel, Switzerland first tested each volunteer’s strength at four times of day (8 a.m., noon, 4 p.m. and 8 p.m.) across four days to find their individual peak and trough. They then randomly assigned 108 older adults (mean age 67, 41% women) to train at their peak time, train at their trough time, or keep their usual lifestyle with no training. Both training groups did the same 12-week program: two supervised full-body strength sessions a week (five exercises, three sets of 8 to 15 reps) plus one 30-minute moderate cycling session. The first two weeks were practice; the next ten built up gradually.[1]
The main outcome was isometric midthigh pull strength, a test where you pull on a fixed bar and the force is measured. The team also measured handgrip strength and appendicular lean mass index, a body-scan measure of arm and leg muscle relative to height.[1]
What it found
- No clear difference between peak and trough training. The gap in midthigh pull strength was 0.06 N·kg-1 (95% confidence interval -0.76 to 0.88), and the gap in lean mass index was 0.03 kg·m-2 (-0.09 to 0.15). Both intervals sit around zero.[1]
- Fixed clock times looked similar too. Groups that trained at 8 a.m., noon, 4 p.m. or 8 p.m. did not show clear differences in adaptation, though those groups were small and the estimates were uncertain.[1]
- The daily rhythm in strength is real. On average, strength differed about 11% between each person’s best and worst time, but individuals ranged from 1% to 34%. Peaks most often landed in the afternoon (32%) or evening (33%), and troughs at noon (40%) or in the morning (29%).[1]
- People kept showing up. Attendance at strength sessions was 91% in the peak group and 93% in the trough group, with no serious adverse events linked to the program.[1]
In other words, feeling stronger at 4 p.m. than at 8 a.m. is a real thing. It just did not turn into bigger gains over 12 weeks.
What this trial can’t tell you
- It tested timing, not whether lifting works. The paper reports small effects when the training groups were compared with the non-training group over this short window. The authors point out that early strength gains in older adults are mostly neural, and visible muscle growth comes slowly.[1] Twelve weeks is a starting line.
- Small timing effects could be hiding. The study was sized to detect an 8% strength advantage for peak training. A smaller edge would not have shown up. Each person’s peak was also estimated from a single four-day test, which is a rough read.[1]
- The group was healthy. Volunteers were independent, with grip strength above average for their age. The authors say the results may not carry over to people who are frail, have sarcopenia (age-related muscle loss) or live with several chronic conditions.[1]
- Participants were older than many Bettering Me readers. If you are in your 40s or 50s, the principle probably holds, but this trial did not test it in your age group.
What to do with this
- Choose the slot you can protect. The World Health Organization recommends muscle-strengthening activity at moderate or greater intensity, working all major muscle groups, on two or more days a week. That is a strong recommendation backed by moderate-certainty evidence for adults.[2] Pick two days and a time that survives a busy week, then treat it like a meeting.
- Copy the trial’s template. Two full-body sessions: five exercises, three sets of 8 to 15 reps, adding load or reps gradually. Add one 30-minute moderate cycling session if you like. For a plan built around your 40s, see how to build muscle reserve in your 40s.
- Hold the time steady, then judge by trend. Write down your top working weight each session and compare month to month, not day to day. The trial’s authors note that declines in muscle mass and strength emerge in the fifth decade of life and accelerate afterwards,[1] so a routine you can keep up is the sensible goal. This 12-week trial cannot say whether timing matters over years.
- Use “I feel strongest then” as a tiebreaker only. If two slots work equally well for your schedule, pick the one where you feel better. Do not rearrange your life to chase a peak. This trial found no clear advantage for it.
If you have a heart condition, joint pain or a recent injury, check with your clinician before starting a new program. Then put two strength sessions on your calendar this week, at the same time both days. For the bigger picture, our post on sleep, strength and cardio shows where this fits.
References
[1] Bruggisser F, Ritter S, Roth R, Ritter ET, Infanger D, Ledergerber R, Hinrichs T, Scheer FAJL, Handschin C, Hanssen H, Knaier R. Effects of Daily Rhythm-Aligned Training on Skeletal Muscle Adaptation in Older Adults: A Randomized Controlled Trial. J Cachexia Sarcopenia Muscle, 2026;17(5):e70390. Population: 108 randomized adults aged 60 to 80 (mean 67; 41% female), 93 analyzed; 12-week program; ClinicalTrials.gov NCT06063135. DOI: https://doi.org/10.1002/jcsm.70390. Finding as used: training at individual peak vs trough time of day produced no clear difference (isometric midthigh pull 0.06 N·kg-1, 95% CI -0.76 to 0.88; handgrip strength -0.21 kg·m-2, -0.68 to 0.26; appendicular lean mass index 0.03 kg·m-2, -0.09 to 0.15); no clear differences between fixed morning, noon, afternoon and evening groups (wide confidence intervals); mean diurnal variation in strength about 11% (individual range 1% to 34%); peak most often in the afternoon (32%) or evening (33%), trough at noon (40%) or morning (29%); resistance-training adherence 91% (peak) and 93% (trough); no intervention-related serious adverse events; training vs non-training comparisons also showed small effect sizes; sample size planned to detect an 8% greater strength gain in the peak group (d = 0.51); peak and trough times derived from a single four-day profiling period; participants healthy and independent, findings may not generalize to frail, sarcopenic or multimorbid people; authors note early adaptations in older adults are predominantly neural and that declines in muscle mass and strength emerge in the fifth decade of life and accelerate afterwards. ↑︎
[2] Bull FC, Al-Ansari SS, Biddle S, Borodulin K, et al. World Health Organization 2020 guidelines on physical activity and sedentary behaviour. Br J Sports Med, 2020;54(24):1451-1462. Population: guideline development for children, adolescents, adults and older adults. DOI: https://doi.org/10.1136/bjsports-2020-102955. Finding as used: adults should do muscle-strengthening activities at moderate or greater intensity that involve all major muscle groups on 2 or more days a week (strong recommendation, moderate-certainty evidence). ↑︎
Kurt Greiner
Kurt is a digital strategist and IT professional blending emerging technology with practical application to help businesses and individuals streamline their digital presence. His current work focuses on the intersection of intentional living and technological resilience, exploring how individuals can leverage modern tools to navigate the second half of life with purpose.
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