[5] Following his Postdoctoral fellowship, Hood joined York University’s School of Kinesiology and Health Science, and the Department of Biology (Faculty of Graduate Studies) as an Assistant Professor in 1988.

[8][9] He was the first to determine that thyroid hormone modifies mitochondria in heart and muscle during growth and development, and repairs mitochondrial defects in diseased cells, in part via increases in protein import.

[10][11][12] He along with co-workers also discovered that contractile activity (i.e. exercise) induces calcium, AMP kinase and reactive oxygen species signaling to increase the transcription of nuclear genes, leading to mitochondrial biogenesis.

[15][16] In a series of papers published in 2007 and 2009, Hood discussed that mitochondrially-mediated cell death (apoptosis) in muscle is increased with age and disuse, and attenuated with exercise.

[22][23] Hood’s research contributed to define the role of mitochondria in terms of sending retrograde signals to the nucleus to activate gene expression in response to mitochondrial stress in muscle.