My work centers on the health aspects of physical activity and fitness, particularly during childhood and adolescence. My research is population-based and integrates my training in community health education, exercise physiology, and epidemiology. I am currently working on a longitudinal cohort study with colleagues at Iowa to examine how genetics, diet, and physical activity influence bone strength in children and adolescents. I am also an investigator on a multi-center trial addressing glycemic control and the incidence, magnitude, and duration of hypoglycemia in children. I have recently begun work with colleagues in South Carolina, Louisiana, and Texas to conceptualize a longitudinal, multi-state cohort study examining determinants of childhood and young adult obesity. Within these projects, I am using electronic monitoring systems to more comprehensively and objectively explore relationships between physical activity and health.
Peterson JJ, Lowe JB, Peterson NA, Nothwehr F, Janz KF, Lobas JG. Paths to leisure physical activity among adults with intellectual disabilities: Self-efficacy and social support. American Journal of Health Promotion, in press.
Janz KF, Medema-Johnson H, Letuchy EM, Burns TL, Torner JC, Willing MC, Levy SM.
Subjective and objective measures of
physical activity in relationship to bone mineral content during late childhood:
The Iowa Bone Development Study. British Journal of Sports Medicine, 42:658-63, 2008.
Peterson JJ, Janz KF, Lowe JB. Physical Activity among adults with intellectual disabilities living in community settings. Preventive Medicine, 47:101-06, 2008.
Puthoff ML, Janz KF, Nielsen DH. The relationship between lower extremity strength and power to everyday walking behaviors in older adults with functional limitations. Journal of Geriatric Physical Therapy, 31:24-32, 2008.
Janz KF, Letuchy EM, Wenthe P, Levy SM. Measuring activity in children and adolescents using self-report: PAQ-C and PAQ-A. Medicine and Science in Sports and Exercise, 40:767-772, 2008.
Janz KF, Gilmore JM, Levy SM, Letuchy EM, Burns TL, Beck TJ. Physical activity and femoral neck bone strength during childhood: The Iowa Bone Development Study. Bone, 41:216-22, 2007.
Janz KF, Gilmore JM, Burns TL, Levy SM, Torner JC, Willing MC, Marshall TA. Physical activity augments bone mineral accrual in young children: The Iowa Bone Development Study. Journal of Pediatrics, 148:793-9, 2006.
Diabetes Research in Children Network (DirecNet) Study Group. Prevention of hypoglycemia during exercise in children with type 1 diabetes by suspending basal insulin. Diabetes Care, 29:2200-4, 2006. Writing committee: Tsalikian E, Kollman C, Tamborlane WV, Beck RW, Fiailio-Scharer R, Janz KF, Ruedy KJ, Wilson D, Xing D, Weinzimer SA.
Darter BJ, Janz KF, Puthoff ML, Broffitt B, Nielsen DH. Reliability and accuracy of the AMP 331 for activity monitoring and energy expenditure prediction. Journal of Physical Activity and Health, 3:277-291, 2006.
Janz KF. Physical activity in epidemiology: Moving from questionnaire to objective measurement. British Journal of Sports Medicine, 40:191-192, 2006.
Weir LF, Nygaard I, Wilken J, Brandt D, Janz KF. Postoperative activity restrictions: Any evidence? J Obstetrics and Gynecology, 107:305-309, 2006.
Peterson, J. Peterson A., Lowe JB, Janz KF. Differential effects of active living on quality of life at various levels of income. Health Education Research, 21:146-56, 2006.
Diabetes Research in Children Network (DirecNet) Study Group: The effects of aerobic exercise on glucose and counter-regulatory hormone concentrations in children with Type 1 diabetes. Diabetes Care, 29:20-25, 2006. Writing committee: Tansey MJ, Tsalikian E; Beck RW, Mauras N, Buckingham RA, Weinzimer SW, Janz KF, Kollman C, Xing D, Ruedy KJ, Steffes MW, Borland TM, Singh R, Tamborlane WV.
Diabetes Research in Children Network (DirecNet) Study Group: Impact of Exercise on Overnight Glycemic Control in Children with Type 1 Diabetes. J Pediatr, 147:528-34, 2005. Writing committee: Tansey MJ, Tsalikian E; Beck RW, Mauras N, Buckingham RA, Weinzimer SW, Janz KF, Kollman C, Xing D, Ruedy KJ, Steffes MW, Borland TM, Singh R, Tamborlane WV.
Janz KF, Burns TL, Levy SM. Tracking of activity and sedentary behaviors in childhood: The Iowa Bone Development Study. American Journal of Preventive Medicine, 29:171-178, 2005.
Freedson PS, Pober D, Janz KF. Calibration of accelerometer output for children. Medicine and Science in Sports and Exercise, 37:S523-S530, 2005. Invited paper for journal supplement funded by the NIH-National Cancer Institute.
Tsalikian E; Beck RW, Kalajian A; Janz KF; Tansey MJ for the Diabetes Research in Children Network (DirecNet) Study Group. Commentary: Function of the GlucoWatch G2 Biographer during exercise. Diabetes Technology & Therapeutics, 7:230-230, 2005.
Janz KF, Broffitt B, Levy SM. Validation evidence for the Netherlands Physical Activity Questionnaire for young children: The Iowa Bone Development Study. Research Quarterly for Exercise and Sport, 76(3):363-9, 2005.
Willing MC, Torner JL, Burns TL, Janz KF, Gilmore J, Marshall TA, Warren JJ, Levy SM. Percentile distributions of bone measures in young Iowa children: The Iowa Bone Development Study. Journal of Clinical Densitometry, 8:39-47, 2005.
