There is a moment in a lot of freestyle strokes where nothing is happening. One hand is out front, flat and still, waiting for the other arm to come over the top. The swimmer feels long and smooth, and the pace clock disagrees.
That waiting moment is the dead spot, one of the few faults that gets praised by accident. It looks like distance per stroke. It is usually a swimmer decelerating.
What is the dead spot in freestyle?
The dead spot is the part of the stroke cycle where neither arm is pushing you forward. The lead arm has finished reaching and has not started pressing, the other arm is still in the air, and for that fraction of a second the only thing acting on you is drag.
Research measures that gap directly, with the Index of Coordination. A study on variability of coordination parameters at 400 m front crawl pace describes it in one line: "The IdC measures the mean lag time that separates the propulsive phases from one arm to the other." The number is negative when there is a gap and positive when the arms overlap, and a study on intracyclic velocity variation and arm coordination in the front crawl names the negative case: "When there was a lag time between propulsive phases of the two arms, the stroke coordination was termed 'catch-up' (IDC < 0)."
Is catch-up timing actually wrong?
No, and this is where most pool deck advice goes off the rails. Distance freestyle is swum in catch-up timing by people who are very good at it.
A meta-analysis of the 400 m front crawl test reports that across the pooled studies "The IdC showed that swimmers have adopted the catch-up coordination model, with an IdC mean of -11%", and that "Expert swimmers in this distance present an IdC from -20% to -10%". The 400 m pace study adds what happens when the speed changes: "At slow paces, expert swimmers have a long gliding phase (IdC<0%), while at fast paces, they overlap the propulsive phases (IdC>0%)."
That kills two bits of folklore at once. A gap between the arms is normal at aerobic pace, so chasing a windmill stroke on every easy length is fighting the water for no reason. And the timing is meant to move with speed, so a swimmer who holds one rhythm from warm up to race pace has a problem however pretty the stroke looks. The fault is not the gap. It is what the front arm does during it.
Why does the pause in front cost me speed?
Because you spend that pause slowing down, and the speed you lose has to be bought back by the next pull. The cost is the acceleration, not the time.
The intracyclic velocity study found that speed inside one stroke cycle swings far more for weaker swimmers: "IVV for elite swimmers was significantly lower (26%) than that for beginner swimmers at all swimming velocities (p<0.01, 7.28 ± 1.25% vs. 9.80 ± 1.70%, respectively)." The same paper ties that variation to the bill you pay for it, noting that "Barbosa et al. (2005) also reported that energy cost, as calculated by dividing total energy expenditure by velocity, was positively correlated with IVV, and suggested that higher IVV was related to low swimming economy."
A flat hand parked out in front is a brake with your body behind it, so the next catch has to lift you back to speed from lower down, thirty times a length. That is why the dead spot hides so well. It does not feel like effort. It feels like gliding.
How do I know whether I have a dead spot?
Count the stroke cycle in three beats and see whether the middle one is empty. Beat one is the hand entering and reaching, beat two is the catch setting, beat three is the press to the hip. A silent moment between one and two is the dead spot, and on an adult stroke it is often a full half second.
Two tests that need no equipment:
- Swim 25 easy, then 25 at race pace and ask whether the timing changed. If both feel identical, your coordination is not moving with your speed the way the research says it should.
- Count strokes for a length, then hold the same time with two more strokes. If the faster turnover does not feel harder, you were carrying a stall, not a glide.
The other way is to film a length from the deck and watch the lead hand rather than the recovery arm everyone watches. If it sits still and flat while the other arm is in the air, you have found it.
What actually causes the lead arm to stall?
Four causes, and they need different fixes, so guessing wastes months.
- Reaching with a straight, flat hand. There is nothing to press against, so the arm waits for the other one. Fixing the freestyle catch removes the reason to wait.
- Rotating too far and sticking. The body rolls onto its side and hangs there, which my post on freestyle body rotation covers.
- Breathing that stops the stroke. The head turns, the front arm waits for it to come back, and the gap doubles on breathing strokes only.
- A kick that switches off in the gap. The legs go quiet exactly when the arms do, so nothing is driving you. The freestyle kick has to keep running through the timing change.
Which drills fix freestyle timing?
A timing set worth doing weekly:
- 6 x 50 counting the three beats in your head, the only goal being that the catch starts before the other hand enters
- 8 x 25 alternating: one length in exaggerated catch-up touching the hands in front, one length in a deliberately overlapping rhythm, so you feel both ends of the range
- 6 x 50 descending 1 to 3 with the stroke count held, so the timing has to compress while the length stays
- 8 x 25 fingertip drag, breathing every stroke to one side, with the front hand set into its catch before the dragging hand passes your shoulder
The second one matters most, because catch-up as a drill works precisely by not being a stroke, and swimmers get in trouble when they race in it. Through all of them the front hand gathers pressure rather than rests. A lead arm with a bent wrist and a slightly high elbow is doing something even when the other arm is in the air, and that is the difference between a glide and a stall.
How do I keep the timing when I get tired?
Take your stroke count at the start and the end of every long set. The gap grows with fatigue because the catch gets lazy and the hand sits out there longer while you gather yourself, so a count that climbs while the split slows means the timing is coming apart, not the fitness. The swim pace calculator shows what those seconds are worth over your distance, and my post on the most common freestyle mistakes covers the faults that travel with this one.
The honest problem is that you cannot see your own front arm. You feel long and smooth in exactly the stroke that is stalling, which is how a swimmer spends a year reinforcing the fault while trying to fix it. A coach sees it in one length, and most adult swimmers do not have one.
SwimRead is a swimming video review app, currently in beta. It supports short, side-view freestyle recordings, shows which automatic measurements are available, and keeps a history and chosen training focus for each swimmer. It does not grade technique or establish that a specific error was detected. Video stays on the phone; technical measurements and body-landmark coordinates are sent as described in the Privacy Policy. Join the beta waitlist for an invitation as places open.