Cycle tracking
Training that listens to how you feel
For women: switch on cycle tracking to log your period and symptoms. On days you say are rough, 3Lite can offer a lighter session or hold your targets steady, as you choose.
Replaces a separate period tracker for training. Part of one app, for one subscription.
- Optional and private
- Goes by symptoms, not the calendar
- Lighter, steady or no change: your call
Cycle tracking. Screens show sample data.
How it works
Cycle tracking, step by step
- 01
Tell 3Lite your life stage
Regular, irregular, hormonal contraception, perimenopause or postmenopause, pregnant or postpartum.
- 02
Log in one tap
Period started or finished, then any symptoms and how strong they are.
- 03
Choose how training responds
On period days and, if you like, strong-symptom days: a lighter session, hold steady, or no change.
- 04
See what's next
A next-period estimate where it makes sense, clearly labelled "not for contraception".
Key features
What you get, and why it helps
- Symptom-led, not phase rules
- Research hasn't found a consistent strength effect by cycle phase, so 3Lite goes by how you actually feel.
- Lighter sessions
- Fewer sets and more in reserve on the days you choose, without breaking your streak.
- A gentle prompt
- After three months without a period, 3Lite suggests speaking to your GP. It never diagnoses.
- Private and deletable
- Never shared, included in your data export, and deletable in one tap.
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Today: day 2 · cramps, moderate · low energy
The numbers
Why it matters
Research and official figures behind this part of 3Lite. See all the numbers.
9 in 10
exercising women in a study of 6,812 reported mood changes or anxiety with their cycle; 86% reported tiredness and 84% stomach cramps.
Source: British Journal of Sports Medicine (Bruinvels et al.), 2021
~90%
Women with the most frequent cycle symptoms had almost a 90% chance of missing or changing training, or using pain relief.
Source: British Journal of Sports Medicine (Bruinvels et al.), 2021
51%
of UK women aged 44 and under use an app or device to track their menstrual cycle.
Source: YouGov, 2024
62% vs 67%
Women in England are still less likely to be active than men: 62.2% meet the activity guideline, compared with 67.3% of men.
Source: Sport England, 2026
Good to know
- Cycle tracking is for planning training around how you feel. It isn't contraception or a medical record.
Is cycle tracking only for women?
Yes. It's offered to women, based on the sex in your profile, and you switch it on in My Profile → Training.
Does 3Lite change my training by cycle phase?
No. It goes by the symptoms you log and the choice you make, never by the date alone.
Also in the same app
TrainingChoose a split or let 3Lite choose, and get a programme built around your days, equipment and experience. Log every set in seconds and drag sessions to another day when life gets in the way.
RecoveryRecovery is one of the three pillars of fitness, so it has its own place in 3Lite: last night's sleep, how much energy you've got, and any injuries. How well you recover shapes how hard 3Lite asks you to push.PrivacyHealth data deserves care. 3Lite asks for your consent before storing it, keeps it private to your account, never sells it or uses it for advertising, and lets you take it or delete it whenever you like.
Start with 14 days free.
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