A wearable device for decreasing the respiratory effort of a subject during sleep, the device comprising: - at least one left bipolar electrode configured for mounting on a selected portion of the subject's skin corresponding with the position of at least one left target muscle including a left masseter, a left pterygoid and/or a left temporalis muscle; - at least one right bipolar electrode configured for mounting on a selected portion of the subject's skin corresponding with the position of at least one right target muscle including a right masseter, a right pterygoid and/or a right temporalis muscle, that is opposite to the left target muscle; - wherein the left and right bipolar electrodes comprise at least two electrically conductive elements having an inter electrode distance between 10 mm to 30 mm, wherein the position and orientation of said electrically conductive elements are adapted in such a way that a first electrically conductive element can be mounted on a target muscle's motor point and a second electrically conductive element can be mounted along the direction of the same target muscle's fibre and aligned therewith; - a stimulator configured to generate a biphasic transcutaneous electrical stimulation to be applied between the two electrically conductive elements of the left and right bipolar electrodes; - wherein the stimulator is configured to generate said electrical stimulation in accordance with at least one stimulation program comprising the following stimulation parameters: a current intensity between 1 mA to 50 mA, a frequency between 1 Hz to 150 Hz, a pulse width between 50 μs to 1000 μs, and a duty cycle that has a stimulation period of 1 sec to 20 sec and/or a rest period of 1 sec to 20 sec; wherein at least the frequency, pulse width and duty cycle are equal between the left and right bipolar electrodes; - wherein said electrical stimulation promotes the contraction of the target muscles to controllably elevate the subject's mandible so as to decrease the respiratory effort. - at least one left bipolar electrode configured for mounting on a selected portion of the subject's skin corresponding with the position of at least one left target muscle including a left masseter, a left pterygoid and/or a left temporalis muscle; - at least one right bipolar electrode configured for mounting on a selected portion of the subject's skin corresponding with the position of at least one right target muscle including a right masseter, a right pterygoid and/or a right temporalis muscle, that is opposite to the left target muscle; - wherein the left and right bipolar electrodes comprise at least two electrically conductive elements having an inter electrode distance between 10 mm to 30 mm, wherein the position and orientation of said electrically conductive elements are adapted in such a way that a first electrically conductive element can be mounted on a target muscle's motor point and a second electrically conductive element can be mounted along the direction of the same target muscle's fibre and aligned therewith; - a stimulator configured to generate a biphasic transcutaneous electrical stimulation to be applied between the two electrically conductive elements of the left and right bipolar electrodes; - wherein the stimulator is configured to generate said electrical stimulation in accordance with at least one stimulation program comprising the following stimulation parameters: a current intensity between 1 mA to 50 mA, a frequency between 1 Hz to 150 Hz, a pulse width between 50 μs to 1000 μs, and a duty cycle that has a stimulation period of 1 sec to 20 sec and/or a rest period of 1 sec to 20 sec; wherein at least the frequency, pulse width and duty cycle are equal between the left and right bipolar electrodes; - wherein said electrical stimulation promotes the contraction of the target muscles to controllably elevate the subject's mandible so as to decrease the respiratory effort.