When I started swimming as an adult, I assumed the hard part would be fitness. It wasn't. The hard part was discovering that almost everything I instinctively did in the water was quietly working against me. I spent months frustrated — out of breath after a single length, convinced I simply wasn't built for swimming — before I understood that I wasn't unfit. I was inefficient. And inefficiency in the pool is the great equaliser: it humbles strong athletes and rewards patient ones.
Over the months that followed, I made every classic beginner swimming mistake, fixed them one by one, and then watched dozens of other new triathletes make the exact same errors. Three of them show up again and again. If your swim progress has stalled, there's a very good chance one — or all three — is the culprit. The good news is that none of them require talent to fix. They require awareness and a little repetition.
Mistake 1: Swimming Too Fast, Too Early
This is the most common swimming mistake I see, and the one I was most guilty of. The pattern is predictable: you push off the wall, sprint the first 25 metres as hard as you can, arrive at the far end gasping, cling to the wall for thirty seconds, then do it all again. It feels like training. It feels like effort. But what you're really doing is teaching your body to associate swimming with panic and oxygen debt.
Speed in the water is a by-product of efficiency, not aggression. When you slow down to a pace where you could almost hold a conversation, three things happen at once: your technique stays intact instead of falling apart, your aerobic system gets the steady stimulus it needs to adapt, and you build the endurance base every faster swim is eventually built on. Counterintuitively, swimming slower for a few weeks is one of the quickest ways to get faster. Ego is the enemy here — leave it in the changing room.
Mistake 2: Lifting Your Head to Breathe
Breathing is where the freestyle stroke lives or dies for most beginners, and the instinct to lift your head to find air is almost universal. It also wrecks your body position. The moment your head rises, your hips and legs sink, and suddenly you're dragging the lower half of your body through the water like an anchor. Every extra ounce of drag is energy you'll never get back.
The fix is body rotation. Instead of lifting your head, rotate your entire body along its long axis, keeping one goggle in the water as you turn. Done correctly, your mouth clears the surface naturally in the little trough your rotation creates — no lifting required. It feels unnatural at first, and it takes deliberate practice to trust that the air will be there. But once it clicks, it's the single biggest efficiency gain available to any beginner swimmer.
"Lift your head and your hips drop. Rotate your body and the air finds you."
Mistake 3: Ignoring the Pull (and Obsessing Over the Kick)
Ask a new swimmer where their power comes from and most will point to their legs. In reality, the overwhelming majority of your propulsion in freestyle comes from your arms — specifically the catch and the pull. Yet beginners pour enormous energy into a frantic kick that produces lots of splash, a sky-high heart rate, and very little forward movement.
What matters is the early catch: the instant your hand enters the water, angle your fingertips slightly downward and grab the water rather than slicing through it. Then pull through with a high elbow and full extension, finishing past your hip. The clearest way to feel this is a pull-buoy set — clip a buoy between your thighs, switch your legs off entirely, and swim using only your arms. The first time I did this I was stunned to find I was barely slower than with a full-effort kick. Proof of how little the kick was contributing, and how much the pull was being neglected.
How to Actually Fix These Swimming Mistakes
Reading about technique changes very little. Seeing yourself swim changes everything. The fastest way to identify which of these mistakes you're making is to have someone film you from the side of the pool for a single length. It's almost always uncomfortable to watch — and instantly clarifying. You'll see the head lift, the sinking hips, and the windmilling arms far more vividly than any coach could describe them.
Then pick one mistake at a time. Don't try to rebuild your whole stroke in a single session — that's a recipe for frustration and a tangled mess in the water. Spend two weeks on body position, then two weeks on the catch, then bring it together. Small, patient corrections compound. The swimmers who improve fastest aren't the ones who train hardest; they're the ones who fix the cheap mistakes first.
Film yourself from the side during one pool session. You'll spot all three mistakes within thirty seconds of footage if you have them — and once you've seen them, you can't unsee them. Awareness is ninety percent of the correction.