Apparatus and method for improving training threshold

A biosensor device for determining a lactate threshold of a subject during exercise, the device comprising:

• a housing;
• a detector disposed in the housing, the detector being configured to detect an oxygenation parameter of a tissue of the subject using Near InfraRed Spectroscopy (NIRS);
• and
• a processor configured to process the oxygenation parameter and determine the lactate threshold of the subject.

A biosensor device for measuring parameters of a subject during exercise, the device comprising:

• a housing;
• a first detector disposed in the housing, the first detector being configured to measure oxygenation parameters of a muscle tissue of the subject;
• a second detector configured to measure photoplethysmography (PPT) of the subject;
• and
• a third detector configured to measure electrocardiography (EKG) and derived systolic time intervals (STI) of the subject.