An external or non-invasive ambulatory medical device comprising: a monitoring component comprising at least one sensing electrode for detecting a cardiac condition of a patient, wherein the monitoring component is configured to monitor heart rate; a motion sensor; at least one processor configured to: operate in a default operating mode, wherein in the default operating mode one or more detection parameters for detecting the cardiac condition of the patient are used; automatically select an activity operating mode if the motion sensor detects a motion indicative of the patient being in an active state or select the activity operating mode based on manual input, wherein in the activity operating mode, the one or more detection parameters for detecting the cardiac condition of the patient are adjusted relative to those of the default operating mode; and provide an alarm comprising an indication that a treatment is about to be delivered and a treatment in response to detecting the cardiac condition of the patient based on, in the default operating mode, the one or more detection parameters, and, in the activity operating mode, the adjusted one or more detection parameters; wherein the at least one processor is configured to, before causing the treatment and after causing the indication that the treatment is about to be delivered, allow the patient to provide an input that causes the ambulatory medical device to refrain from delivering the treatment to the patient, wherein a length of time to receive the input is longer in the activity operating mode than a default length of time provided in the default operating mode. a monitoring component comprising at least one sensing electrode for detecting a cardiac condition of a patient, wherein the monitoring component is configured to monitor heart rate; a motion sensor; at least one processor configured to: operate in a default operating mode, wherein in the default operating mode one or more detection parameters for detecting the cardiac condition of the patient are used; automatically select an activity operating mode if the motion sensor detects a motion indicative of the patient being in an active state or select the activity operating mode based on manual input, wherein in the activity operating mode, the one or more detection parameters for detecting the cardiac condition of the patient are adjusted relative to those of the default operating mode; and provide an alarm comprising an indication that a treatment is about to be delivered and a treatment in response to detecting the cardiac condition of the patient based on, in the default operating mode, the one or more detection parameters, and, in the activity operating mode, the adjusted one or more detection parameters; wherein the at least one processor is configured to, before causing the treatment and after causing the indication that the treatment is about to be delivered, allow the patient to provide an input that causes the ambulatory medical device to refrain from delivering the treatment to the patient, wherein a length of time to receive the input is longer in the activity operating mode than a default length of time provided in the default operating mode. operate in a default operating mode, wherein in the default operating mode one or more detection parameters for detecting the cardiac condition of the patient are used; automatically select an activity operating mode if the motion sensor detects a motion indicative of the patient being in an active state or select the activity operating mode based on manual input, wherein in the activity operating mode, the one or more detection parameters for detecting the cardiac condition of the patient are adjusted relative to those of the default operating mode; and provide an alarm comprising an indication that a treatment is about to be delivered and a treatment in response to detecting the cardiac condition of the patient based on, in the default operating mode, the one or more detection parameters, and, in the activity operating mode, the adjusted one or more detection parameters; wherein the at least one processor is configured to, before causing the treatment and after causing the indication that the treatment is about to be delivered, allow the patient to provide an input that causes the ambulatory medical device to refrain from delivering the treatment to the patient, wherein a length of time to receive the input is longer in the activity operating mode than a default length of time provided in the default operating mode.