14 Day Lag Period Between Sleep Deficit And New Injury

Picture by Jeffrey Bown from his book Goodnight Darth Vader

Well, it's that time of the year again, where school has ended (for Singapore schools) and work in the office starts to wind down. Many of our patients are already traveling before the Christmas holiday.

Many of us, in this last month of the year, will experience less sleep due to travel, parties, family, children and shift work.

Though we would love to catch up with sleep when sleep is disturbed, even with training/ exercising taking a lower priority, it becomes more difficult with all the committments.

I often tell my patients (who are still training seriously) that there is up to 51 percent increased risk of injury especially for endurance athletes who get less than 7 hours of sleep per day in the last 2 weeks (Johnson et al, 2020).

The study recruited runners, triathletes, swimmers, cyclists and rowers. Subjective health complaints (SHCs) like psychological/ lifestyle factors, cardiorespiratory and gastrointestinal problems to investigated to see if they were associated with sleep quality, training load and new injury episodes.

Applying a 7 day and 14 day lag period, a shared frailty model was used to investigate new injury risk associations with total SHCs and sleep quality.

The investigators found that 7 day lag psychological/ lifestyle SHCs were significantly associated with new injury risk. This was in contrast to cardiorespiratory and gastrointesinal SHCs were not significantly associated with new injury risk. 

New injury risk had a significant increased association with a 14 day lag if there was less than 7 hours of sleep per day. There was no significant association with total SHCs, sleep quantity and training load factors.

The authors concluded that athletes need to be aware of the lag period between low sleep quality and its subsequent impact on new injury risk. In order to minimise the risk of new injuries, psychological/ lifestyle SHCs and sleep quantity should be considered.

Be mindful. Bear in mind that this end year period may be a time when we are most susceptible to new injury if we are deprived of sleep.

Reference

Johnston R, Cahalan R, Bonnett L et al (2020). General Health Complaints And Sleep Associated With New Injury Within An Endurance Sporting Population. J Sci Med Sport. 23(3): 252-257. DOI: 10.1016/j.jsams.2019.10.013