Out of Time: the effect of 'jet lag' on rowing performance

Whether you’re hopping across a couple of time zones or flying halfway around the world, travel for competition or simply the adventure of rowing somewhere new is part of the life of many rowers. All on its own, long trips are exhausting, even for the most elite athletes. Add into that the havoc shifting time zones plays on the human body and the prospects for a personal best performance when it matters might seem bleak.

Fortunately, there are helpful ways that athletes can prepare for and deal with the effects of jet lag to set themselves up for the best trip possible. World Rowing spoke with South Africa’s Dr. Christa Janse van Rensburg to find out more about what rowers need to know to be ready when taking to the air before taking to the water. Dr. van Rensburg is the Associate Professor and Head of Department: Section Sports Medicine at the University of Pretoria.

BODIES OUT OF TIME

To start, it is important to understand that “jet lag” means the fatigue of a body being quite literally taken out of time. “Your circadian rhythm (body clock) is out of sync with the destination time zone,” explains van Rensburg, who recently lead the creation of an international consensus statement of medical experts on the topic of jet lag in athletes. “The more time zones crossed, the longer it takes the circadian rhythm to re-entrain and the longer-lasting and more severe the symptoms of jet lag.”

Depending on the direction travelled, your body clock is either running fast (going west) or falling behind (going east). It takes about the body about half a day to recover for every time zone crossed to the west and a full day for every time zone crossed to the east. That said, “there is also a large inter-individual variation/difference in how jet lag affects each individual,” says van Rensburg. In other words, not everyone will experience jet lag in the same way. Also, adds van Rensburg, there is “no evidence that athletes are more vulnerable than the general population.”

PERFORMANCE IMPACTS

From poor sleep quality and quantity to lower levels of blood oxygen to reduced sprint performance, the impact of jet lag can be significant if not properly managed.

Van Rensburg pointed out some work of an Australian colleague, Dr. Peter Fowler, whose work has also confirmed a more significant effect on performance from travel eastward vs. travel westward. One key point from one of Fowler’s studies that van Rensburg cites is that even for athletes on teams that engage in regular short distance travel between time zones, “travel fatigue could be cumulative and may accrue over the course of a season.”

SLEEP IS KEY

“Preserve sleep,” advises van Rensburg. “Never travel if you are suffering from sleep debt. Make use of strategic naps.”

Normally, “one should aim for 7 to 9 hours sleep per night,” suggests van Rensburg, stressing the importance of practicing “good sleep hygiene.” Besides the role of a good set routine for sleep in day-to-day performance, it also means that when preparing to travel you can start acclimatising your body in advance more effectively.

“Adapt your sleep routine before you travel,” suggest van Rensburg. “From three days before you travel, you can shift your sleep and wake time one hour later per day when travelling west and one hour earlier per day when travelling east.”

Either before hand or on the ground at your destination, “light exposure” and “avoidance” are two strategies with some science behind them to help transition your body into its new time zone.

“Exposure to bright light in the hours leading up to the individual’s minimum core body temperature (at approximately 4am for most people) tends to push the internal clock later in time, whereas bright light in the hours immediately afterward pushes the clock earlier in time.”

ADDITIONAL TIPS AND TRICKS

Van Rensburg and colleagues lay out a number of recommendations for athletes, coaches and entourage before, during and after travel in their consensus document. Here are a few of the big ones:

Before travel:

• Prioritise and protect sleep
• Plan travel well in advance and ensure eating venues and locations resting en route
• Synchronise training plan load and intensity to account for travel
• Keep hydrated and attend to nutritional needs

During travel:

• Sleep – take naps, use eye masks, earplugs, reduced/no screen time, lean back if seat allows
• Stay healthy as much as possible (illness prevention) – regular hand washing/sanitising
• Keep hydrated – avoid caffeine at least 6 hours before sleep time
• Regular but smaller meals
• Take breaks en route if possible – move frequently/walk around/stretch

After travel:

• Sleep – use eye masks, earplugs, no screen time before sleep time or naps – take naps as early in the day as possible to establish/preserve nighttime sleep routine
• Keep hydrated and attend to nutritional needs – caffeine in the local morning, but avoid in afternoon
• Keep training low to moderate initially