Each January, millions engage in intense workout routines and rigid fitness challenges in a bid to enhance personal fitness for the year ahead.
But women-led period and cycle tracker Clue warns that much mainstream fitness advice is based on a flawed assumption: that bodies perform the same way every day.
For people with menstrual cycles, hormonal fluctuations can shape energy, mood, sleep, motivation, perceived effort and recovery, meaning following a generic, one-size-fits-all training plan could in fact be the cause of increased burnout, injury risk and drop-off.
This January, Clue in partnership with ŌURA, the wearable health platform, are calling for a smarter approach to 2026 fitness plans: cycle-aware, data-led routines, that are built around strength, flexibility and recovery.
The January Fitness Boom
Insights from ŌURA prove January fitness culture is real compared to other winter months.
In the UK, ŌURA saw a 28.2 per cent increase in the percentage of days with a logged workout in January 2025 vs December 2025 (excluding housework, walking and “other”).
In the US, the increase was 19.5 per cent over the same period.
Dr Charis Chambers, chief medical officer at Clue, said: “Beginning the new year with a commitment to regular exercise is a common way to prioritise health, but abruptly starting intense fitness training can actually increase risks of health issues.
“This is why the ‘push through it’ fitness culture we often see in January can be particularly harmful for women and people with menstrual cycles.
“Rather than pushing through fatigue, pain or disrupted sleep, people will see greater long term benefit from adapting workouts to how their bodies feel across the cycle and using data to understand what’s normal for them.”
Data-driven Exercise
With wearable fitness tracking now mainstream, more women and people with cycles are building fitness habits using biometric feedback such as sleep, temperature trends and recovery.
This provides a broader picture of their health, allowing them to spot changes, monitor health goals, and adapt routines in ways that feel aligned with their bodies.
Dr Chris Curry, MD, PhD, clinical director of women’s health at ŌURA, said: “By combining ŌURA’s readiness, sleep, and activity data with Clue’s detailed cycle tracking, women have a more complete picture of how hormonal fluctuations impact overall health and well-being.
“This integration enables members to observe how their menstrual cycle phases may align with changes in sleep patterns, energy levels, stress resilience, and recovery capacity, informing more flexible, cycle-aware fitness routines that can be adapted to the body’s natural rhythm.”
Everyday high intensity exercise doesn’t work long term
January fitness culture often equates “more” and “harder”, leading many people to gravitate towards daily HIIT-style workouts that promise quick change.
But experts warn that this approach isn’t always sustainable, particularly for people with menstrual cycles.
Eve Lepage, senior reproductive health specialist at Clue, said: “High-intensity workouts create short-term increases in cortisol, which is normal.
“But repeatedly stacking intense sessions without adequate recovery can lead to fatigue, disrupted sleep and burnout.
What the evidence supports instead is balance, anchoring routines in strength training at least twice per week, using higher intensity in moderation, and allowing flexibility based on how you feel.”
By contrast, excessive cardio or high-intensity training without sufficient recovery can negatively impact the body’s cortisol patterns.
Clue user data shows that walking (32 per cent), rest days (24 per cent), and strength training (16 per cent) are the most commonly tracked activities, highlighting that consistent, everyday movement, rather than extreme routines, forms the foundation of how most people actually exercise.
According to Clue, this is an important reminder during January’s fitness push: movement doesn’t need to be extreme to be effective.
Cycle-awareness doesn’t mean rigid ‘cycle syncing’
While cycle-synced workouts have gained recent attention, Clue experts emphasise that there is a lack of scientific evidence to support this effectiveness as a one-size fits all approach.
Instead, a more effective approach is cycle aware and symptom-guided, using menstrual cycle tracking to understand individual patterns over time and adjusting training intensity based on how the body feels day-to-day.
“Cycle awareness isn’t about following strict rules, it’s about self-knowledge,” said Eve Lepage.
“Some people notice changes in energy, mood or perceived effort across their cycle. Some feel stronger or more energetic during the late follicular phase (on the days leading up to ovulation), while feeling more tired during the luteal phase (after ovulation and before the next period), while others don’t notice much difference at all.
Rather than asking ‘What should I do in this phase?’, a better question is: ‘How do I usually feel here?’ and adjust accordingly.”
Clue health experts encourage an approach to fitness that prioritises long-term health over short-term intensity.
Rather than aiming for perfection, Clue experts recommend building routines around four evidence-based principles, designed to support strength, recovery, and consistency:
- Strength training as the foundation – Supporting long-term muscle, metabolic and bone health, strength training is one of the most effective ways to build resilience and reduce injury risk. It also offers flexibility: intensity and load can be adjusted based on symptoms, fatigue, or low readiness days.
- Adequate recovery (non-negotiable) – Recovery is when the body adapts and improves. Without enough rest days, people are more likely to experience persistent fatigue, disrupted sleep, reduced motivation, or injury, all of which increase drop-off and burnout.
- Aerobic training with flexible intensity — not “push through it” culture – Sustainable fitness is built around adapting workouts to real-life signals. On lower-energy or symptom-heavy days, a routine might shift from HIIT to lower-impact movement like cycling, or reduce duration, all without “failing” the plan. Most important is to move regularly, on most days, even when it’s just going for a walk on some days.
- Listening to bodily signals (including cycle changes) – Persistent fatigue, pain, disrupted sleep, emotional exhaustion and even cycle changes such as irregular, missed or lighter periods can be signs the body is under excessive stress. Clue experts emphasise that the menstrual cycle is a vital sign, and significant changes can indicate it’s time to scale back and prioritise recovery.
Together, Clue’s cycle insights and ŌURA’s biometric tracking help people better understand how menstrual cycle phases may align with changes in energy, mood and recovery — supporting training routines that are sustainable year-round.
Head to www.helloclue.com for more information and to download the app and learn more about Oura Ring and Oura health insights at www.ouraring.com
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