An inexpensive, fast and reliable estimation of cardiorespiratory fitness

Importance of Cardio Respiratory Fitness

Statement Paper from American Heart Association


“At a minimum, all adults should have CRF estimated each year using a non-exercise algorithm during their annual healthcare examination. Clinicians may consider the use of submaximal exercise tests or field tests as alternatives because these involve individual-specific exercise responses. “


Jogging and Exercise   

What is Cardio-Respiratory Fitness?

Cardio Respiratory Fitness reflects metabolism and as the name indicates lungs and heart interact by supply of oxygen to tissues and organs and by elimination of carbon dioxide. Maximal oxygen capacity of a person means the maximal oxygen consumption determined until exhaustion and is called VO2-max. Cardio respiratory fitness measured as VO2-max correlates not only to fitness but to general health.


Seismofit® System

Cardiorespiratory fitness (CRF) measured as VO2-max may be determined by the Seismofit® System by use of seismocardio graphy. Seismofit® measures vibrations arising from heartbeats and transmitted to the chest. Each heart has its own signature relating to opening and closing of valves and the relaxation and contraction of the heart chambers. The system further includes an adhesive patch, a smartphone App and a cloud-based algorithm.

3 minutes recording   


Golden Standard VO2-max
Traditional ergometry 8-12 min plus time for preparation

Monitoring VO2-max

Current methods are too complicated

Ergometer cycling or treadmill running are golden standards for determining VO2-max. Various protocols are used i.e. increasing load in given time intervals with measure of oxygen consumption during the test until exhaustion.  Submaximal testing protocols not reaching maxial pulse and exhaustion may be used if the test person may be at any health risk with maximal exercise. The test will when including dressing and preparation take up to 30 minutes.


Sports Medicine

Use of Cardio Respiratory Fitness in Sports

VO2-max is a predictor of performance, although its correlation to athletic success in endurance sports is only 30-40%, with other factors such as sustainable lactate threshold, motivation, training, etc. also playing a role. In general, however the higher a VO2-max the more potential for a successful performance in an aerobic endurance event.
World class men will have fitness scores ranging from 60 to 90 and women from 50 to 72.


Our Mission

Making Cardiorespiratory Fitness measurement a part of everyone’s health check  

VentriJect was established as a spin-out from a leading research center in cardiology at Aalborg University in 2018 and is situated in Hellerup near Copenhagen, Denmark.

Ryvangs Alle 81
2900 Hellerup
Copenhagen Denmark