cLOcK Lab

Translational sleep and circadian therapeutics for health across the lifespan

cLOcK lab logo

Administrative Research Center (ARC), Room A46
3100 Marine Street
Boulder, CO 80309-0554

Personnel

Research Interests

The lab aims to develop and implement translational approaches grounded in sleep and circadian science to promote optimal mental and physical health across the lifespan in humans. Here, we investigate how biological timing, light exposure, timed activity, and sleep-wake regulation interact to influence cognitive performance, mood, and physiological resilience. Through the integration of mechanistic studies, wearable technology, machine learning applied to large-scale datasets, and clinical trials, this lab aims to develop personalized, scalable interventions that improve daily functioning, reduce disease risk, and promote healthy longevity.

Upcoming Research Projects

  • Aging, Mild Cognitive Impairment, Sleep-wake disturbances
  • Light exposure, aging, sleep-wake disturbances

Opportunities for Graduate Students and Postdoctoral Fellows

  • The cLOcK Lab will be recruiting a graduate student for Fall 2026, supported by existing research funding. Additional opportunities may be available for students with external fellowships. Details about applying to the Integrative Physiology Graduate Program as a direct admit can be found Ìýhere. ÌýPlease contact me if you are interested in joining the lab.
  • Postdoctoral Fellow training is available contingent upon research funding.
  • For more information, contact Renske.Lok@colorado.edu.

Recent publications

For a complete list of publications, .

  • O. Walch, F. Tavella, J.M. Zeitzer, R. Lok, Beyond phase shifting: targeting circadian amplitude for light interventions in humans. ÌýSleep (2025) 48 (1), zsae247
  • R. Lok, L. Weed, J. Winer, J.M. Zeitzer. Adverse effects of late sleep on physical health in a large cohort of community-dwelling adults. European Journal of Internal Medicine (2025) 134, 66-74
  • R. Lok, L. Weed, J. Winer, J.M. Zeitzer. Perils of the nighttime: Impact of behavioral timing and preference on mental health in 73,888 community-dwelling adults.Ìý
    Psychiatry research (2025) 337, 115956
  • R. Lok, J. Qian, S.L. Chellappa. Sex differences in sleep, circadian rhythms, and metabolism: Implications for precision medicine, Sleep medicine reviews (2024), 75, 101926
  • N. Meyer, R. Lok, C. Schmidt, S.D. Kyle, C.A. McClung, C. Cajochen, F. A.J.L. Scheer, M.W. Jones, S.L. Chellappa, The sleep–circadian interface: A window into mental disorders. Proceedings of the National Academy of Sciences (2024) 121 (9), e2214756121
  • R. Lok, S. Ancoli-Israel, K.E. Ensrud, S. Redline, K.L. Stone, J.M. Zeitzer, Timing of outdoor light exposure is associated with sleep-wake consolidation in community-dwelling older men. Frontiers in Sleep (2023) 2, 1268379
  • M. Spitschan, L. Kervezee, R. Lok, E. McGlashan, R.P. Najja, the ENLIGHT consortium, ENLIGHT: A consensus checklist for reporting laboratory-based studies on the non-visual effects of light in humans. EBioMedicine (2023) 98

Funding

  • 2024 - 2029, NIH K99/R00 Pathway to Independence Award. 2024-2026 under grant number K99AG08484