Research Institute for Sport & Exercise Sciences FACULTY OF SCIENCE Circadian rhythms and swimming performance Greg Atkinson Chronobiology Research Group Research Institute for Sport and Exercise Sciences Liverpool John Moores University

Research Institute for Sport & Exercise Sciences FACULTY OF SCIENCE Contents Evidence for endogenous diurnal variation in swimming performance? “Optimising performance”: Jet-lag Morning ↓ performance: Overridden with warm-ups? Shifted with exercise, bright light and/or melatonin?

Research Institute for Sport & Exercise Sciences FACULTY OF SCIENCE Swimming performances: morning heats vs evening finals Pyne et al. J Sports Sci 2004; 22:

Research Institute for Sport & Exercise Sciences FACULTY OF SCIENCE Controlled time trials Baxter and Reilly, Brit J Sports Med 1983; 17:  3.5% ↑2.5%

Research Institute for Sport & Exercise Sciences FACULTY OF SCIENCE Edwards et al., Chronobiol Int 2002; 19: Measuring endogenous component: Constant routines Time of day (h) Body temperature (°C) Sleep

Research Institute for Sport & Exercise Sciences FACULTY OF SCIENCE Edwards et al., Chronobiol Int 2002; 19: Time of day (h) Body temperature (°C) Measuring endogenous component: Constant routines Awake

Research Institute for Sport & Exercise Sciences FACULTY OF SCIENCE Kline et al. J Appl Physiol 102: 641–649, Semi-constant routine approach  2.3%

Research Institute for Sport & Exercise Sciences FACULTY OF SCIENCE The underlying circadian system

Research Institute for Sport & Exercise Sciences FACULTY OF SCIENCE Body clock Intergeniculate leaflet Activity rhythm Retino- Hypothalamic tract Light rhythm Melatonin Pineal gland Vision The working model Waterhouse et al., Keeping in time with your body clock, Oxford University Press Outputs

Research Institute for Sport & Exercise Sciences FACULTY OF SCIENCE Body clock Intergeniculate leaflet Activity rhythm Retino- Hypothalamic tract Light rhythm Melatonin Pineal gland Vision The working model Waterhouse et al., Keeping in time with your body clock, Oxford University Press Outputs Masking

Research Institute for Sport & Exercise Sciences FACULTY OF SCIENCE ControlWarm-up Performance time (s) Morning Afternoon * * # Masking the body clock with a warm-up? Atkinson et al. J Sports Sci 2005; 23: * *

Research Institute for Sport & Exercise Sciences FACULTY OF SCIENCE Body clock Intergeniculate leaflet Activity rhythm Retino- Hypothalamic tract Light rhythm Melatonin Pineal gland Vision The working model Waterhouse et al., Keeping in time with your body clock, Oxford University Press

Research Institute for Sport & Exercise Sciences FACULTY OF SCIENCE A ‘phase-response curve’ for exercise? Atkinson et al. Eur J Appl Physiol 2007; 99: Approx 4am

Research Institute for Sport & Exercise Sciences FACULTY OF SCIENCE Timing of morning exercise in the taper phase? Edwards et al., Int J Sports Med 2005; 26:  2%

Research Institute for Sport & Exercise Sciences FACULTY OF SCIENCE Body clock Intergeniculate leaflet Activity rhythm Retino- Hypothalamic tract Light rhythm Melatonin Pineal gland Vision The working model Waterhouse et al., Keeping in time with your body clock, Oxford University Press

Research Institute for Sport & Exercise Sciences FACULTY OF SCIENCE Phase-response curve for light Waterhouse et al. Neurosci Let 1998; 245: Approx 4am

Research Institute for Sport & Exercise Sciences FACULTY OF SCIENCE Evening bright light delays the body temperature rise Atkinson et al., Int J Sports Med 2008; 29: Bright Light

Research Institute for Sport & Exercise Sciences FACULTY OF SCIENCE Body clock Intergeniculate leaflet Activity rhythm Retino- Hypothalamic tract Light rhythm Melatonin Pineal gland Vision The working model Waterhouse et al., Keeping in time with your body clock, Oxford University Press

Research Institute for Sport & Exercise Sciences FACULTY OF SCIENCE Phase response curve for melatonin Approx 4am

Research Institute for Sport & Exercise Sciences FACULTY OF SCIENCE Melatonin is a hypnotic! M or P Atkinson et al. Ergonomics 2005;48: :15

Research Institute for Sport & Exercise Sciences FACULTY OF SCIENCE Dietary melatonin Hardeland and Pandi-Perumal, Nutr Metab 2005;2:1-15

Research Institute for Sport & Exercise Sciences FACULTY OF SCIENCE Summary Good evidence for endogenous circadian variation in swimming performance Variation not completely ameliorated by warm- up interventions Timing of circadian rhythm might be manipulated by careful timing of reliable and safe synchronisers to circadian system –Bright light –Exercise –Dietary melatonin?

Research Institute for Sport & Exercise Sciences FACULTY OF SCIENCE Recommendations for optimizing morning performance It seems sensible to be exposed to bright light and take some exercise in the morning during the taper phase…………. Minimal exposure to evening bright light and exercise in taper phase Experimentation: –Sleep deprivation (prior evening heats + early waking)? –Timing of pre-race meals? –Individual differences (chronotype)?

Research Institute for Sport & Exercise Sciences FACULTY OF SCIENCE Thanks to: Mike Peyrebrune Clare Todd Ben Edwards Dave Barr Helen Jones

Research Institute for Sport & Exercise Sciences FACULTY OF SCIENCE Martin and Thompson, Int J Sports Med 2000; 21: 387–392 Is the circadian variation robust?

Research Institute for Sport & Exercise Sciences FACULTY OF SCIENCE Synchronisers of the human circadian system

Research Institute for Sport & Exercise Sciences FACULTY OF SCIENCE Measuring endogenous component: 2. Temporal isolation “Mammoth Cave”, Kentucky Temporal Isolation Lab, Liverpool

Research Institute for Sport & Exercise Sciences FACULTY OF SCIENCE Synthesis of melatonin Atkinson et al., Sports Med 2003; 33:

Research Institute for Sport & Exercise Sciences FACULTY OF SCIENCE Swim bench performance Reilly and Marshall J Swim Res 1991; 7:  16%

Research Institute for Sport & Exercise Sciences FACULTY OF SCIENCE Is the circadian variation resistant to change? Arnett, J Strength Con Res 2001; 15: ↑ 1.1%