Does jet lag lower exercise performance?

Short answer

Yes. After crossing several time zones, 5-second peak power fell by about 8% for 2 days after arrival, with bigger drops in body-measured experiments after flying east and in the morning. It was nearly back after 3~4 days.

Does jet lag lower exercise performance?
Time zones → body clock out of sync → less strength and speed. True?
Many people worry that jet lag will sap their strength before an overseas competition or trip. We checked whether a body clock thrown off by a flight really lowers performance, and if so, for how long.
Right after arrival, it dropped
About 8% less 5-second peak power, for two days
In a study combining three experiments with flights across several time zones, peak power over 5 seconds fell from 9.8 to 9.0, about 8% lower. Work done over 30 seconds fell from 213 to 199, about 7% lower. The drop lasted for 2 days after arrival and was nearly gone after 3~4 days.
Flying east hit harder
Same 8-hour difference, direction decided it
In 10 people tested while flying between Australia and Qatar across 8 time zones, sleep was shorter and fatigue worse after the eastward trip home. Repeated-running distance dropped the day after arrival, and on day two the 20 m sprint was slower than after flying west. In US Major League Baseball records, jet lag effects also showed up mostly after eastward travel.
It dropped in the morning, and in some movements
Afternoon grip and sprinting held steady
In 27 people who flew east across 7 time zones, those given a dummy pill had weaker morning grip for the first 3 days, while afternoon grip and jumping did not drop. In 5 people after a long eastward flight, the morning 30 m sprint time was unchanged, while standing jump height went down.
Pro game results changed too
Win rates fell on road trips across time zones
In the NBA, teams won 63.8% at home and 50.8% away, and the away gap appeared when crossing 1~2 time zones and after westward travel. In the 2020 games played in one place with no travel, 55.7% and 44.3% were not a meaningful difference. Across 3,489 WNBA games, home teams with eastward jet lag also performed worse.
How long does it last?
Body function 3~4 days, jet lag symptoms about a week
In 19 people, jet lag symptoms lasted 5~6 days after crossing 6 time zones westward and 7 days after crossing 8 time zones eastward. Training performance was worst in the first 4 days after the westward flight. A 2026 review of 89 studies found recovery markers returned at about one day per time zone crossed.
Managing light and sleep reduced the drop
The managed group did better in jumps and sprints
Of 20 people who crossed 8 time zones eastward, the 10 who got light and kept sleep habits matched to the destination's clock had better jump power and 5 m and 20 m sprints over 4 days, and slept longer. In Southern Hemisphere pro rugby from 1996~2016, the cost of crossing 12 time zones eastward shrank from 5.8 to 3.7 points per match.
Summary: it drops, more going east, right after arrival, and in the morning
It was nearly back after 3~4 days
Jet lag lowered strength and running ability for 2~4 days after arrival, more after flying east, and grip dropped in the morning. For an important competition or test, arriving as many days early as the number of time zones crossed, so recovery markers fully return,, and getting light and sleep on the local clock, is what works.