A player who sheltered through a two-hour lightning delay comes back jumping 3.5 percent lower and sprinting up to 1.8 percent slower, and only a plyometric re-warm-up matched to his idle time pulls those numbers back.

Staff need the reset rule, a log of each player’s last hard effort, a re-warm-up matched to the gap, and a separate plan for substitutes who never played. The existing weather rules tell officials when play can resume. The existing research tells physiologists what passive waiting does to a player’s legs. Neither document connects the two. Staff have to read the reset clock and then put each player through the re-warm-up his idle time calls for.

The reset rule creates unknown delay length

FIFA stops the match for 30 minutes when lightning is detected within a 13-kilometer radius, and every new strike restarts the clock. ¹ U.S. Soccer’s guidance says outdoor activity may resume 30 minutes after the last thunder or lightning, and the 30-minute clock restarts every time lightning flashes or thunder sounds. ³

Because each new strike restarts the clock, a storm that keeps flashing can hold the players inside for two hours. Staff cannot plan for a fixed wait. They need a protocol that works whether the delay lasts 35 minutes or two and a half hours.

What passive waiting costs

Abade, Sampaio, Goncalves, Baptista, Alves and Viana tested 22 elite Portuguese under-19 players after a standard warm-up. Without a re-warm-up, counter-movement jump fell 3.5 percent, Abalakov jump fell 4.5 percent, and 10-meter and 20-meter sprint times worsened by 1.4 and 1.8 percent. Plyometric re-warm-up held jumps almost level and improved sprint times by 1.6 percent in both distances. ⁷

The sample is under-19, not World Cup senior players, so the exact numbers do not transfer directly. But passive waiting cut the jumping and sprinting that pressing, aerial duels and recovery runs are built on, and the plyometric re-warm-up brought them back.

What recent delays looked like from the inside

France-Iraq in Philadelphia delayed two hours and 11 minutes including the halftime break. Players re-emerged for warm-ups about one hour and 40 minutes after sheltering. France defender Jules Kounde said the squad used cycling to stay active. Iraq coach Graham Arnold said his players had to relax, watch clips and get ready again. ^{8 9}

Chelsea-Benfica in Charlotte stopped in the 85th minute and restarted almost two hours later. Chelsea players used exercise bikes and kick-ups. Chelsea captain Reece James said it was difficult to stay in the flow with substitutions and players trying to get warm and stay warm. Chelsea conceded a 95th-minute penalty before winning in extra time. ¹⁰

France cycled to stay active and Chelsea reached for exercise bikes and kick-ups. Neither side described a plan that tied a player’s last match-speed effort to what he did during the wait.

The four-part staff protocol

The 15-minute threshold is a practical cut derived from the re-warm-up research, where passive intervals of that length already produced measurable jump and sprint losses. Staff should treat it as a starting point and adjust based on their own squad’s testing data.

Substitutes are the overlooked case

The Premier League pre-match protocol shows how structured the normal warm-up sequence is. Outfield players start no earlier than 45 minutes before kick-off, warm up for no more than 30 minutes, and clear the pitch 10 minutes before kick-off. ⁶

A substitute who sheltered without playing has no recent match-intensity effort to decay from. Their body is closer to a pre-match state than a half-time state. Sending them on after a two-hour delay with only the starter’s abbreviated re-warm-up skips the preparation that the pre-match protocol was designed to provide.

Netherlands-Tunisia in Kansas City kicked off at 6 p.m. inside a storm window that ran from 4 p.m. to 7 p.m. with a 60 to 70 percent chance of storms continuing into the evening. ^{1 2} Any substitute entering after a delay during that window needed a different warm-up from a starter who had been pressing and sprinting five minutes before sheltering.

Once the lightning window opens, staff are moving players to shelter, watching the reset clock, and talking to match officials. The re-warm-up steps have to be on paper before the forecast turns, so the physio is reading from a sheet during the delay instead of inventing one.