Strapless heart rate and heart rate variability

continuous body temperature monitoring

Advanced body sensors

Body temperature

Body temperature

Body temperature is an important, regulated physiological parameter. It normally lies around 36.5 to 37.4 degrees Celsius and undergoes natural variations due to factors such as time of day, physical and mental activity, food intake, hormones, psyche, water and electrolyte balance. It is also affected by external parameters such as ambient temperature, wind strength, and humidity. To remain constantly around 37 degrees Celsius, core body temperature is regulated by internal mechanisms like heat production and heat dissipation.

The cosinuss° technology is the first wearable device that is able to monitor core body temperature continuously during activity, enabling new applications not only in sports but in nearly every aspect of life.

Body temperature in sports

Body temperature in sports

Due to its very close connection to the body´s energy balance, body temperature is a highly relevant parameter for determining/influencing physical performance and exercise control in sports.

Dehydration and overheating

The most obvious interpretation of high body temperature is overheating. If the body is unable to cool itself down for a long period of time, the first symptoms of overheating appear: goosebumps, nausea, and significant breakdown in performance since all the remaining energy is used for the cooling process.
How can you counteract dangerous overheating?
By hydrating, wearing breathable clothes, slowing physical exertion, or by using different methods to cool your body (e.g. with cooling vests).
Once the body is overheated, there is no easy way of recovering through hydration or other cooling actions. Your body needs a rather long recovery time to reach the normal level of performance again, highlighting with that the importance of preventing overheating in first place. One good way to do this is by continuously monitoring your level of dehydration with a device measuring your body temperature.

cosinuss° aims to solve this unsolved problem and wants to provide a sensor device that is able to monitor dehydration/overheating continuously during activity. Athletes will be informed about their dehydration level using a color system. When a dangerous zone is entered, one or several of the above mentioned actions need to be taken in order to prevent overheating.

Determination of performance

Another use of continuous body temperature data lies in the increased accuracy of other performance measures. This is based on the fact that body temperature exerts significant influence on the heart rate:

Your heart rate increases almost proportionally with performance when you start exercising. Thus, in this initial period there´s a very good correlation between heart rate and performance which makes heart rate a legitimate parameter for performance control. This, however, changes when your body temperature rises above normal, and the life-sustaining cooling process of your body kicks in. Cooling is primarily achieved through perspiration and heat emission. Heat transport from the inside to the periphery of the body is achieved through your blood and the dense network of veins and arteries between skin and hypoderm. If there is more heat to be dissipated than normal, the main blood circulation increases to eight to twelve times its normal rate. Consequently, your heart has to beat more often and so heart rate increases. This increase in heart rate, however, is not caused by performance but solely by the cooling process! This detail can result in huge mistakes sneaking into performance calculations that are only based on heart rate.

If you can monitor heart rate and body temperature together you have the data to eliminate this error. Consequently, it will be possible to determine individual performance limits of athletes with significantly higher accuracy, enabling better exercise control and improvements in performance.
cosinuss° is pursuing this approach in cooperation with renowned universities in order to bring performance measures to the next level.

Heart rate

Heart rate

Under certain circumstances, heart-rate provides a very good method to determine exercise intensity. Demand for oxygen rises with training intensity in the initial phase of exercising, making the heart beat faster and thus driving up heart-rate. In this phase, heart rate increases almost proportionally with training intensity making it an excellent measure to calculate work load. This, however, changes with rising body temperature and the life-sustaining cooling process of the body that is kicking in.

Why is that?

So far, heart-rate can be monitored either with chest straps, which are mostly reliable but inconvenient, or with heart-rate monitor watches which are more convenient but unreliable.
cosinuss° One is filling this gap and enables you for the first time to monitor heart rate both conveniently and with a high degree of accuracy.

Heart rate zones

  % of maximum heart rate
Recovery (aerobic) appr. 60 %
Endurance (aerobic) appr. 75 %
Stamina (aerobic) appr. 85 %
Economy (anaerobic) 82 - 87 %
Speed (anaerobic) 88 - 92 %


Our Mission

cosinuss° aims to use continuously available body temperature data during activity to:

  • monitor and visualize level of dehydration during activity
  • improve accuracy in calculation of calories burned
  • detect and prevent heat induced illnesses
  • bring performance measures and exercise control to the next level