Step 1 Changes in heart rate variability during short –term isometric skeletal muscle contraction. This work aims to investigate cardiac autonomic nervous system modulation during short term isometric skeletal muscle contraction. The study was done on thirty male non-smoker volunteers, aged 19-23 years (mean=20.46±1.27), body mass index (BMI) ranged 15.729.05(mean=22.84±3.84), with history of no medical problems, normal physical examination and laboratory tests, including complete blood count, blood chemistry, chest X-ray and electrocardiography, were selected from among the medical students of King Abdul-Aziz University (KAAU) in Saudi Arabia Kingdom. عنوان الوثيقة Document ( )Title المستخلص )Abstract( )ISSN( ردمد اسم الدورية )Journal Name( MANSOURA MEDICAL JOURNAL )Volume( المجلد Vol.38 No.3&4 4July, & Oct., 2007 : إلى : من Issue ( العدد )Number سنة النشر Publishing ( )Year )Pages( الصفحات Step 2 خا لد: )(ع khaled: )E( عظام: )(ع ezam: )E( جده االسم األول للباحث First name of the researcher االسم األخير للباحث Last name of the researcher العنوان Step3 في أسرع وقتmed.it@hotmail.com تعبئة هذا النموذج لكل بحث وإرسالها إلى Fill out this form for each research, and send it to med.it@hotmail.com