New York, NY / Sep 1, 2026 / NRTHRN Strong
NRTHRN Strong, the Copenhagen-born fitness concept redefining functional training through a Nordic lens, today announced a new partnership with Extension Health, a Manhattan-based longevity medicine practice focused on advanced diagnostics, regenerative therapeutics and longitudinal health monitoring. The partnership connects NRTHRN Strong’s intentional approach to training with Extension Health’s data-driven philosophy of understanding what is actually happening inside the body
After completing an initialVO2 Max assessment at Extension Health, NRTHRN Strong members will receive a complimentary second test at either of the clinic’s two New York City practices. The initial assessment is available at Extension Health’s standard rate of $250. The offer is designed to encourage members to establish a baseline and then retest to see how their fitness improves over time
Following their complimentary VO2 Max assessment, members will receive a $250 credit toward Extension Health’s Comprehensive Diagnostics Package, which includes a DEXA scan, resting metabolic rate (RMR), VO2 Max, grip strength, core longevity bloodwork and a longevity consultation. A complimentary results consultation is also included with each VO2 Max test, giving members an opportunity to review their results with Extension Health’s dedicated team of clinicians
“People are putting more time and energy into their health than ever before, but most still have little insight into whether that effort is making a difference,” said Nicoline Roth, Founder and CEO of NRTHRN Strong. “With Extension Health, our members can establish a baseline, continue training and then measure what has changed. VO2 Max matters because it’s not just a measure of fitness, it’s an important indicator of cardiorespiratory health and long-term longevity. This makes the connection between the work you put in and the progress you can see much more tangible.”
Extension Health members will receive access to NRTHRN Strong classes at the studio’s Founding Membership Rate. Together, the two brands offer a more comprehensive approach to performance, pairing advanced health diagnostics that show what’s happening inside the body with intentional training designed to help members act on those insights
Three Ways to Train at NRTHRN Strong
NRTHRN Strong’s methodology is built around three pillars: strength, cardio and mobility, with every class designed to build functional strength, improve cardiovascular fitness and support long-term movement
At the heart of the experience is the patented NRTHRN Trainer, originally developed for cross-country skiers, which is paired with functional, floor-based strength work to deliver a low-impact, full-body <a href="https://healthylife7.com/nhl-summer-sizzle-workout-edition-alex-bump/” title=”NHL Summer Sizzle Workout Edition: Alex Bump”>workout. NRTHRN Strong features three distinct classes:
- Strong, the flagship class, fuses strength training with intense intervals to train VO2 Max, alternating between total-body work on the NRTHRN Trainer and dynamic, muscle-focused floor exercises with dumbbells.
- Cardio is designed to maximize VO2 Max and build endurance that supports longevity, using strategic intervals and sustained efforts to deliver real-time metrics and high output in minimal time.
- Sculpt is based on Pilates-inspired principles and deep muscle activation, a low-impact, high-focus format that targets the stabilizers through slow, deliberate movements and closes with a short mindful moment.
The immersive studio environment draws inspiration from Nordic design, with lighting inspired by the Northern Lights and a minimalist aesthetic. Rather than chasing fitness trends or quick fixes, NRTHRN Strong is designed for people who view their health as a long-term investment and want to build the strength, fitness and mobility to keep moving well for years to come
Turning Training Into Measurable Progress
VO2 Max measures the maximum amount of oxygen the body can use during exercise and is widely recognized as a standard measure of aerobic capacity and cardiorespiratory fitness. Rather than relying on estimates from a wearable device, Extension Health measures oxygen consumption and carbon dioxide production directly using a metabolic cart during a progressive treadmill test
During the test, which takes approximately 15 to 30 minutes, speed and incline gradually increase while a mask and heart-rate monitor track respiratory and cardiovascular data. Results are reviewed immediately afterward by Extension Health’s clinical team, with a full report provided to the member
Beyond producing a VO2 Max number, the test provides information that can help establish individualized training zones based on actual physiology, including maximum heart rate and ventilatory threshold. Because VO2 Max is responsive to training, repeat testing can provide a tangible way to track changes in aerobic fitness and refine a training program
“At Extension Health, we believe data is most valuable when it leads to action,” said Dr. Jonathann Kuo, Founder of Extension Health. “VO2 Max testing gives people a clear picture of their current cardiorespiratory fitness and provides objective data that can be tracked over time. Partnering with NRTHRN Strong creates a natural connection between measuring where you are and having a training environment designed to help you move forward.”
Located at 35 W. 21st Street, NRTHRN Strong Flatiron is a year-round fitness destination for smarter, more sustainable training. Inspired by Nordic principles of balance, simplicity, and community, the Manhattan studio provides a welcoming environment where everyone can train hard, recover well, and connect with others
To learn more or become a member, follow NRTHRN Strong on Instagram and visit the website. For a deeper understanding of your health and performance, follow Extension Health on Instagram and schedule an VO2 Max assessment through their website
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About NRTHRN Strong and Nicoline Roth
Founded by Nicoline Roth, NRTHRN Strong is a boutique fitness studio rooted in Nordic wellbeing and the belief that movement is part of a well-lived life. With studios in New York City’s Flatiron district and Copenhagen’s Nordhavn, NRTHRN Strong combines strength, cardio and mobility in a low-impact, full-body workout designed for long-term health and performance
At the heart of every class is the NRTHRN Trainer, a patented machine originally developed for cross-country skiers and exclusive to NRTHRN Strong. Real-time performance data allows members to track their progress while functional strength work complements the machine-based training. Built for people who see health as a long-term investment, NRTHRN Strong takes a longevity-focused approach to fitness, helping people build strength, improve cardiovascular fitness and move well for years to come
Nicoline Roth, born in Copenhagen and deeply connected to her Nordic heritage, founded NRTHRN Strong to bring a more intentional, low-impact approach to strength and longevity training. She is also the co-founder of BEBOLD, an international women’s community and brand-building partner for female-led businesses
About Extension HealthExtension Health is a Manhattan longevity medicine practice built on a simple premise: data without intervention isn’t medicine. Founded by Dr. Jonathann Kuo — a double board-certified physician with peer-reviewed research and academic appointments at Mount Sinai and Northwell — Extension Health is the only NYC clinic delivering advanced diagnostics, regenerative therapeutics, and longitudinal monitoring under one roof. From the radiation-free Omega360Scan 3T MRI to therapeutic plasma exchange and EBOO ozone dialysis, every protocol is built from the patient’s own biology and re-tested over time. No referrals, no handoffs — just clinical continuity from the first scan to the next intervention. Healthcare 3.0, practiced.
Press ContactsNRTHRNStrong@aiir.agency
Will Allen
press@extension.health
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