Zona Plus and Isometric Handgrip Training: What the Evidence Shows

Updated October 2026: we replaced overstated benefit claims with the current research on isometric handgrip training, added the device's FDA status and current model, and removed an expired coupon and affiliate link.

Decades ago, research commissioned by the U.S. Air Force into keeping fighter pilots conscious under high g-forces led to an unexpected discovery.

According to Zona Health, cardiopulmonary physiologist Dr. Ronald L. Wiley noticed that some pilots who squeezed a handgrip as part of his experiments had lower blood pressure afterward. He went on to develop a computer-controlled handgrip that guides users through a structured isometric exercise session. That device is now called the Zona Plus.

The Zona Plus is a handheld, software-controlled isometric handgrip device that fits in the palm of your hand. The current model is the Zona Plus Series 3.

Cardiovascular conditioning.

Using a series of visual and auditory cues, the Zona Plus guides the user through an entire isometric exercise session in just under 12 minutes. After each session, the Zona Plus provides feedback on performance and stores this data for over a year, and the Series 3 also syncs results to a Zona Health online account. Heads Up has supported Zona data alongside other metrics like blood pressure, as shown in the 2022 report below.

The Zona Plus customizes itself for each user at the start of every session by measuring "maximum voluntary contraction" (MVC) in each hand, then guiding four two-minute holds, alternating hands, at a target pressure. It appeals to people who want a short, seated routine, and to those with joint pain, because isometric exercise involves no joint movement.

What Clinicians Should Know About Its FDA Status

Zona describes the device as intended for adjunctive use in the maintenance of overall cardiovascular wellness, alongside (not instead of) an existing exercise routine. It is not FDA cleared or approved to treat high blood pressure. In a 2019 warning letter, the FDA told Zona Health that blood pressure control claims required premarket review the device did not have. Zona is now sponsoring a randomized pivotal trial of the Zona Plus in adults with elevated blood pressure or hypertension, which began recruiting in 2025. Clients should not change or stop blood pressure medication based on handgrip training.

What the Research Says About Isometric Handgrip Training

Isometric Exercise and Blood Pressure

Isometric resistance training as a modality (including handgrip protocols similar to Zona's four two-minute holds) has been studied extensively. A 2016 meta-analysis of 11 randomized trials found average reductions of about 5 mmHg systolic and 4 mmHg diastolic. A 2023 network meta-analysis of 270 randomized trials in the British Journal of Sports Medicine found isometric training produced the largest average reductions in resting blood pressure of the exercise types compared (about 8 mmHg systolic and 4 mmHg diastolic). The American Heart Association's 2013 scientific statement on alternative approaches rated isometric handgrip as Class IIb, Level of Evidence C, meaning it may be considered, with less evidence behind it than aerobic exercise.

Sustained Muscle Tension

Each Zona session holds a sustained, submaximal contraction for the full two minutes of each segment, rather than repeating short lifts. In research protocols, isometric handgrip training typically uses about 30% of maximal voluntary contraction, a submaximal effort that can be done seated.

Endothelial Function and Nitric Oxide

In laboratory research on rabbit aorta, isometric contraction activated endothelial nitric oxide synthase through a calcium-independent pathway (Fleming et al., 1999). In humans, eight weeks of isometric handgrip training improved brachial artery flow-mediated dilation, a marker of nitric oxide-dependent endothelial function, in medicated hypertensive patients (McGowan et al., 2007) and in healthy young men and women (Badrov et al., 2016).

Zona and Grip Strength

Zona also markets the device for muscle stability and grip strength. Grip strength is a useful functional metric to track in its own right, and the Zona Plus records MVC at the start of every session, so changes can be followed over time.

Difference Between Isometric & Concentric Workouts

What is isometric exercise?

"Isometric" comes from the Greek for "equal measurement." As this relates to exercise, isometric exercise is the type of muscle contraction in which the muscle is tensed and working, but not actively shortening or lengthening (with no joint movement).

Comparatively, concentric contractions are the type of contractions in which a muscle, or muscle group, is shortening (such as the abdominal muscles during a sit-up) and eccentric contractions are the type of contractions in which a muscle, or muscle group, is lengthening (such as in the lowering phase of the sit-up).

While all types of muscle contractions are important for overall muscle function and development, isometric exercise has unique benefits.

Isometric Exercise Benefits

Randomized trials of isometric handgrip training have shown it can:

• Lower resting blood pressure (as a training modality, not as a claim for any specific device)
• Improve endothelial function (flow-mediated dilation)

Because there is no joint movement, it is also a seated, joint-friendly option for people who find conventional exercise difficult.

Isometric exercise is meant to complement, not replace, aerobic and dynamic resistance training. Zona advises users to talk to their physician before starting, which is especially relevant for clients with cardiovascular conditions.

Tracking Isometric Training Outcomes With Your Clients

If you recommend isometric handgrip training, the useful question is whether it is working for each client. That means looking at session adherence and grip data next to home blood pressure from a connected cuff such as Withings, plus wearable and lab data. Heads Up unifies labs, wearables, medical devices and EHR data in one longitudinal patient record, with 100+ integrations. You can set up handgrip training as a protocol with adherence tracking, use threshold alerts to flag blood pressure readings that need attention, and review AI pre-visit briefs that summarize what changed since the last visit. Learn more about remote patient monitoring with Heads Up.

See how Heads Up tracks home blood pressure and device data for your clients: request a demo.

Where to Get the Zona Plus

The Zona Plus Series 3 is sold directly by Zona Health at zona.com, with a 90-day satisfaction guarantee and a one-year warranty (extendable to three years) as of October 2026.