Sleep and Athletic Performance: The Impact of Restriction and Extension

I. Introduction

The majority of existing literature on sleep has predominantly focused on sleep restriction and its far - reaching consequences for health and performance. Nevertheless, an emerging body of research is now delving into the potential implications of sleep extension, particularly in the context of athletic performance. It is widely acknowledged that sleep serves as a fundamental determinant of recovery and performance enhancement.

Notwithstanding this understanding, it is estimated that over one - third of the American population fails to achieve adequate sleep. The American Academy of Sleep Medicine recommends that individuals between the ages of 18 and 60 should sleep for a minimum of seven hours per day.

II. The Significance of Sleep

A. Health and Performance Consequences of Inadequate Sleep

Failure to meet the recommended sleep requirement has been closely associated with a plethora of chronic conditions, including heart disease, stroke, diabetes, high blood pressure, and other adverse health and performance outcomes.

1. Resistance Training Performance

A study exploring the effects of sleep deprivation on resistance training performance reported significant decrements in strength during bench press, deadlift, and leg press exercises. Additionally, researchers noted an increase in subjective feelings of difficulty and elevated sleepiness scores. The reduction in strength persisted until the fourth consecutive night of sleep restriction. Moreover, mood, fatigue, and other subjective indicators of sleep deprivation escalated after just one night of nocturnal sleep restriction.

1. Cardiovascular, Respiratory, and Metabolic Responses in Endurance - Trained Athletes

A research investigation into the cardiovascular, respiratory, and metabolic responses to sleep restriction in endurance - trained athletes revealed that, following partial sleep deprivation, there were statistically significant increases in heart rate (P < 0.05) and ventilation (P < 0.05) during sub - maximal exercise, as compared to baseline measurements. At maximal exercise, both variables were also significantly augmented, while peak oxygen consumption (VO₂) decreased (P < 0.05), despite no difference in maximal sustained exercise intensity.

1. Alertness, Coordination, and Psychomotor Characteristics

Sleep restriction has been shown to undermine alertness, coordination, and other psychomotor traits. For instance, a 2009 study by Edwards et al. demonstrated that participants in the sleep - restricted group experienced a concomitant decline in dart - throwing performance.

1. Cognitive Restitution and Attentional Mechanisms

Sleep is known to play a crucial role in cognitive restitution. Research consistently indicates that restricted sleep impedes attentional mechanisms, such as reaction time and coordination.

1. Time to Return to Baseline Performance

Varying degrees of sleep restriction have been shown to prolong the time required to revert to baseline performance. Chronic sleep restriction, in particular, exhibits a longer refractory period compared to acute restriction before returning to normal levels.

1. Sprint Performance and Muscle Glycogen Content

A study examining the effects of sleep restriction on sprint performance and muscle glycogen content found that sleep loss, along with associated reductions in muscle glycogen and increased perceptual stress, diminished sprint performance and disrupted pacing strategies during intermittent - sprint exercise among male team - sport athletes.

1. Inter - individual Differences in Resilience to Sleep Deprivation

There are substantial inter - individual differences in resilience to sleep deprivation, with some individuals experiencing more pronounced performance declines than others under similar conditions.

B. Body Composition and Performance

The role of body composition in performance, although perhaps less conspicuous, is also highly relevant, especially in sports with weight classes and where power - to - weight ratios are critical determinants of success.

Sleep deprivation has been demonstrated to have significant detrimental effects on body composition. One study found that sleep curtailment decreased the proportion of weight lost as fat by 55% (1.4 vs. 0.6 kg with 8.5 vs. 5.5 hours of sleep opportunity, respectively; P = 0.043) and increased the loss of fat - free body mass by 60% (1.5 vs. 2.4 kg; P = 0.002). This was accompanied by markers of enhanced neuroendocrine adaptation to caloric restriction, increased hunger, and a shift in relative substrate utilization towards the oxidation of less fat.

III. Sleep Extension and Athletic Performance

A. Research Findings on Sleep Extension

A 2011 study aimed to explore the effects of sleep extension on various aspects of athletic performance and other cognitive measurements. The researchers discovered that total objective nightly sleep time increased during sleep extension compared to baseline by 110.9 ± 79.7 min (P < 0.001). Subjects demonstrated improved performance in timed sprints following sleep extension (16.2 ± 0.61 sec at baseline vs. 15.5 ± 0.54 sec at the end of sleep extension, P < 0.001). Shooting accuracy also improved, with free - throw percentage increasing by 9% and 3 - point field - goal percentage increasing by 9.2% (P < 0.001). Mean PVT reaction time and Epworth Sleepiness Scale scores decreased following sleep extension (P < 0.01). POMS scores improved, with increased vigor and decreased fatigue sub - scales (P < 0.001). Subjects also reported enhanced overall ratings of physical and mental well - being during practices and games.

It is important to note that the subjects initially slept between 6 - 9 hours per night, and during the intervention, they were instructed to record a minimum of 10 hours in bed each night. However, it should be emphasized that 10 hours in bed does not equate to 10 hours of sleep. Due to practical limitations, the study used time in bed as a reasonable proxy for total sleep, although adopting a 10 - hour nocturnal sleeping schedule may not always be feasible.

B. Alternative Sleep Strategies

1. Bi - phasic and Polyphasic Sleep

A fragmented sleep pattern, characteristic of bi - phasic (2 phases) or polyphasic (3 + phases) sleep approaches, has shown beneficial effects in subjects with sleep disorders.

1. Napping

Napping has been proven to meaningfully improve cognitive performance. Given that total cumulative sleep throughout the day is a reasonable metric for recovery and athletic performance, incorporating naps can be an effective strategy to increase total sleep, enhance recovery, and boost athletic performance when extending nocturnal sleep is not practical. A 10 - minute nap has been shown to significantly improve alertness and cognitive performance, and longer naps of +30 minutes also confer significant benefits. However, longer naps may lead to sleep inertia, a period of cognitive impairment following awakening from a longer - duration nap (+30 minutes). While sleep inertia does not persist throughout the day, it may be advisable to schedule longer naps away from cognitively demanding tasks such as work or training.

IV. Practical Guidelines for Sleep Quality Enhancement

The National Institute of Health provides additional resources to improve sleep quality:

• Establish a Routine: Go to bed and wake up at the same time each day.

• Exercise Regularly: Engage in 20 - 30 minutes of exercise per day, but refrain from exercising within a few hours of bedtime.

• Avoid Stimulants: Steer clear of caffeine, nicotine late in the day, and alcoholic beverages before bed.

• Relax Before Bed: Try activities such as taking a warm bath, reading, or following another relaxing routine.

• Create a Sleep - Friendly Environment: Minimize bright lights and loud sounds, maintain a comfortable room temperature, and avoid having a TV or computer in the bedroom.

• Don't Lie Awake in Bed: If unable to fall asleep, engage in other activities like reading or listening to music until drowsy.

• Seek Professional Help: Consult a doctor if experiencing sleep problems or excessive daytime exhaustion.

There is substantial evidence suggesting that sleep extension up to 10 hours per night can enhance performance. However, the benefits may vary, as recovery requirements are inherently individual.

References

1. “1 in 3 adults don’t get enough sleep.” CDC Newsroom, Media Relations Press Release, Feb 18, 2016. Accessed March 24, 2021.

2. Thomas Reilly & Mark Piercy (1994). “The effect of partial sleep deprivation on weight - lifting performance.” Ergonomics, 37:1, 107 - 115.

3. Mougin F, Simon - Rigaud ML, Davenne D, Renaud A, Garnier A, Kantelip JP, Magnin P. “Effects of sleep disturbances on subsequent physical performance.” Eur J Appl Physiol Occup Physiol. 1991;63(2):77 - 82.

4. Edwards BJ, Waterhouse J. “Effects of one night of partial sleep deprivation upon diurnal rhythms of accuracy and consistency in throwing darts.” Chronobiol Int. 2009 May;26(4):756 - 68.

5. Morteza Taheri, and Elaheh Arabameri. “The Effect of Sleep Deprivation on Choice Reaction Time and Anaerobic Power of College Student - Athletes.” Asian J Sports Med. 2012, Mar; 3(1):15 - 20.

6. Belenky G, Wesensten NJ, Thorne DR, Thomas ML, Sing HC, Redmond DP, Russo MB, Balkin TJ. “Patterns of performance degradation and restoration during sleep restriction and subsequent recovery: a sleep dose - response study.” J Sleep Res. 2003 Mar;12(1):1 - 12.

7. Skein M, Duffield R, Edge J, Short MJ, Mündel T. “Intermittent - sprint performance and muscle glycogen after 30 h of sleep deprivation.” Med Sci Sports Exerc. 2011 Jul;43(7):1301 - 11.

8. Bulbulian R, Heaney JH, Leake CN, Sucec AA, Sjoholm NT. “The effect of sleep deprivation and exercise load on isokinetic leg strength and endurance.” Eur J Appl Physiol Occup Physiol. 1996;73(3 - 4):273 - 7.

9. Takeuchi L, Davis GM, Plyley M, Goode R, Shephard RJ. ‘Sleep deprivation, chronic exercise, and muscular performance.” Ergonomics. 1985 Mar;28(3):591 - 601.

10. Money I, Waterhouse J, Atkinson G, Reilly T, Davenne D. “The effect of one night’s sleep deprivation on temperature, mood, and physical performance in subjects with different amounts of habitual physical activity.” Chronobiol Int. 1998 Jul;15(4):349 - 63.

11. Nedeltcheva AV, Kilkus JM, Imperial J, Schoeller DA, Penev PD. “Insufficient sleep undermines dietary efforts to reduce adiposity.” Ann Intern Med. 2010 Oct 5;153(7):435 - 41.

12. Cheri D. Mah, MS, Kenneth E. Mah, MD, MS, Eric J. Kezirian, MD, MPH, and William C. Dement, MD, Ph.D. “The Effects of Sleep Extension on the Athletic Performance of Collegiate Basketball Players.” Sleep. 2011 Jul 1; 34(7):943–950. Published online 2011 Jul 1. Accessed March 24, 2021.

13. MasayaTakahashif. “The role of prescribed napping in sleep medicine,” Science Direct. Sleep Medicine Reviews, Volume 7, Issue 3, June 2003, Pages 227 - 235. Accessed March 24, 2021.

14. Smith, S.S., Kilby, S., Jorgensen, G. et al. “Napping and nightshift work: Effects of a short nap on psychomotor vigilance and subjective sleepiness in health workers.” Sleep Biol. Rhythms 5, 117–125 (2007).

15. Mats Gillberg. “The effects of two alternative timings of a one - hour nap on early morning performance.” Biological Psychology. Volume 19, Issue 1, August 1984, Pages 45 - 54

16. Tietzel AJ, Lack LC. “The recuperative value of brief and ultra - brief naps on alertness and cognitive performance.” J Sleep Res. 2002 Sep;11(3):213 - 8.