New HIIT Program Launching This June at Onyx
A new way to train at Onyx
This June, Onyx Karen launches our most demanding programme yet: a fully reimagined High-Intensity Interval Training experience built around the way our members actually train. We have spent the last six months testing structures, work-to-rest ratios, and recovery protocols with our coaches and a small group of advanced members. What you will step into in June is the result.
If you have ever felt that traditional cardio is too long, too repetitive, and never quite delivers the conditioning you want — this is for you.
What makes this HIIT different
Most HIIT classes on the market are improvised: 45 seconds on, 15 seconds off, repeated until exhaustion. That works, but only for a while. The body adapts within weeks and progress stalls.
Our program is structured around three repeating blocks:
- Power Output — short, maximal-effort intervals (10–20 seconds) designed to recruit fast-twitch fibers and improve anaerobic capacity.
- Sustained Threshold — longer working sets (60–120 seconds) that push your lactate threshold and build the engine you need for life outside the gym.
- Active Recovery — never standing still. Mobility flows, breath work, and movement reset between rounds.
Each six-week block progresses in volume, density, and intensity — so what worked for you in week one will not be enough in week six. That is the point.
The schedule
The programme runs three times per week:
- Monday — Lower Body Power
- Wednesday — Upper Body & Conditioning
- Friday — Full-Body Engine
Sessions are capped at 12 members per group so coaching stays personal. Saturday open gym slots are reserved for members who want an extra recovery-focused session.
Who it is for
The honest answer: most members. You do not need to be an athlete. But you do need to be willing to be uncomfortable for short bursts and to trust the structure.
If you are returning from injury, brand new to training, or pregnant, speak with our head coach before enrolling — we will recommend an alternative entry point and progress you in.
How to sign up
Spots open to members on June 1st at 6:00 AM via the member app. Founding members get priority access 48 hours earlier. The first cohort is capped at 60 members across three time slots.
We expect to fill up. If conditioning has been the missing piece in your training, this is the one to commit to.
See you on the floor.