You felt it in the room. Now let's explain it.
Your body doesn't move the same way every day, and it was never meant to. Across your cycle, your hormones rise and fall. They shape your energy, your strength, your mood and how you recover. Some days you're ready to lift heavy and push hard. On other days, your body is asking you to slow down, stretch and rest. Both are strength.
Only 6% to 9% of sports science research focuses solely on women (Irman and Lianingsih, 2025). For too long, women have been told to train like men and to show up at the same intensity every single day. We are changing this.
28 is adidas' first hormone-led approach to movement. Instead of asking you to fight your body, we're inviting you to listen to it.
The name comes from the commonly recognised 28-day menstrual cycle. But your cycle is yours. It might be shorter, longer, or different from month to month. The day ranges in this guide are a starting point. Your body is the final word.
Your cycle moves through four phases, and each one has its own colour, energy and way of moving. In each phase you'll find:
Every piece in the 28 Performance Range is made from 0% polyester. We use natural and responsibly made fibres such as bamboo, Tencel™ lyocell, merino wool and organic cotton, so your skin can breathe and nothing synthetic comes between you and your body.
The Rhythm Within
Day 1–5
Rest is part of the rhythm.
Your period has started, and oestrogen and progesterone are at their lowest point of the whole cycle. It's completely normal to feel tired, heavy, crampy or more inward than usual. Your body is shedding and renewing, which is real work, even when you're sitting still.
This isn't the week to prove anything. It's the week to be kind to yourself.
Movement here isn't about burning or building. It eases cramps, lifts your mood and keeps your body flowing. If your body says rest, rest. That counts too.
Menstrual BlendVital hormone supportKIKO — VITALS × adidas 28In collaboration with Kiko
Your blend for comfort, replenishment and gentle energy.
Your softest, safest week deserves your softest set.
Day 6–13
Feel it building.
Your period has ended and oestrogen is beginning to rise. With it comes a lift. You may notice more energy, a brighter mood, sharper focus and a renewed motivation to move. This is your body's fresh start. You may also recover more easily between sessions.
This is the phase to try something new, build momentum and gradually ask a little more of yourself.
Your body is ready to learn, so it's a great time to master a new skill or book a class you've been curious about.
Follicular BlendVital hormone supportKIKO — VITALS × adidas 28In collaboration with Kiko
Your blend for rising energy and a strong foundation.
Made to move with you as your energy rises.
Day 14–16
This is your peak.
Oestrogen reaches its peak and a surge of luteinising hormone triggers ovulation. Testosterone rises slightly too. This is often when you feel your strongest, most confident and most social. Energy is high, motivation is high, and your body is ready to perform.
Own it. This is your power window.
One note from the guide: some research suggests your ligaments may be slightly more lax around ovulation. Take your warm-up seriously and prioritise good form as you push hard.
Ovulation BlendVital hormone supportKIKO — VITALS × adidas 28In collaboration with Kiko
Your blend for performance, power and recovery.
One piece. Full power.
Day 17–28
Slow it down. Stay grounded.
After ovulation, progesterone becomes your dominant hormone. Your body temperature rises slightly, and your energy begins to ease. Towards the end of this phase, you might notice bloating, breast tenderness, cravings, disrupted sleep or a shorter fuse. These are all common PMS signs.
Your body is preparing for a new cycle. Move with intention, not intensity.
As the phase goes on, gently lower the intensity. Listening to your body now sets you up for a smoother next cycle.
Luteal BlendVital hormone supportKIKO — VITALS × adidas 28In collaboration with Kiko
Your blend for balance, calm and comfort.
Gentle on your body when it needs it most.
