Effects of Zero-Time Exercise (ZTEx) on Inactive Adults With Insomnia

Inclusion Criteria:

• Adults age 18-65 years old;
• Chinese Hong Kong residents who are able to communicate in Cantonese or Mandarin;
• A current clinical Diagnostic and Statistical Manual of Mental Disorders-fifth edition (DSM-5) diagnosis of insomnia disorder (Primary in nature) according to the Brief Insomnia Questionnaire (BIQ), a validated diagnostic tool. The criteria include having difficulties in falling asleep, difficulties in staying asleep, or early morning awakening with clinically significant consequences for daily life for at least 3 months;
• Insomnia Severity Index total score of at least 10 indicating insomnia at the clinical level;
• Willing to give informed consent and comply with the trial protocol;
• Ambulant and independent in activities of daily living;
• Physically inactive which refers to less than 150 minutes moderate-intensity activity per week or less than 75 minutes vigorous-intensity activity per week, or an equivalent combination of moderate- and vigorous- intensity activity.

Exclusion Criteria:

• Evidence of association of insomnia with medical conditions, other sleep disorders, or side-effects of medications;
• Use of medication or psychotherapeutic components for insomnia or other psychiatric disorders;
• Other possible psychiatric disorders including generalized anxiety disorder (GAD), major depressive disorder (MDD), posttraumatic stress disorder (PTSD), psychosis as screened by structural clinical interview of DSM-IV;
• cognitive impairment preventing informed consent or understanding of instructions (score < 22 in Montreal Cognitive Assessment Hong Kong version);
• Shift work;
• body mass index equal to or over 27.5, the obese criteria for Asians;
• Unsafe conditions or incapable to exercise as recommended by their physician.