Whereas textbooks depict metabolism in perfect homeostasis, disturbances occur in real life. One particularly relevant disturbance, caused by excess food and alcohol consumption and exacerbated by genetics, is reductive stress. New work by Goodman et al. identifies a biomarker of reductive stress and uses a gene therapy solution in mice. This work suggests how exercise and an accessible nutritional technology can synergistically increase catabolism and relieve reductive stress.