How To Train For A Triathlon

The Swim, The Bike, The Run

Most people think a triathlon is just three sports glued together. It's not. It's one sport with three transitions, and the training needs to reflect that. You can be a great swimmer, a strong cyclist, and a decent runner and still fall apart on race day if you haven't trained the connections between them. I spent three years doing this wrong before I figured it out. My first sprint distance race, I swam a personal best, biked fast, and then the run completely fell apart because my quads were tight and my form broke down by kilometer two. I crossed the line slower than I would have on a solo run. That's the triathlon for you.

How To Train For A Triathlon

The foundation is volume, but not the kind that breaks you. Start with 3-4 swim sessions, 3 bike sessions, and 3 runs per week. Keep most of it easy. I'm talking conversational pace, heart rate zones two and three. The mistake everyone makes is training too hard on too few days, then wondering why they're injured by week six. Swimming is where most people struggle, and it's not because they can't swim. It's because they haven't built the skill to swim efficiently in a pack, in open water, while your body is already tired from the transition area. Do drill work. Fist swimming, catch-up drill, single-arm drills. Ten minutes of that before you start your main set will improve your swim more than just hammering laps mindlessly. I used to do this wrong for months until a coach made me slow down and focus on the catch phase. My swim time dropped by forty seconds per kilometer in two months.

Transition Training

This is the part nobody talks about enough. T1 and T2 aren't free minutes. A poorly executed transition can cost you five to ten minutes in a sprint, and up to fifteen in an Olympic distance. Practice getting in and out of wetsuits. Practice mounting and dismounting your bike. Set up a practice zone in your garage or driveway and time yourself. I once saw someone take eight minutes to get through transition because they'd never practiced it. That's half the bike leg right there. For T1, strip down to your bike gear in the car park if you're allowed, or practice the full sequence at home. Helmet on, shoes on, glasses, watch. Lay everything out in the exact order you'll need it. For T2, the challenge is different. You've just run and your feet are swollen. Practice taking off your running shoes quickly. Velcro works better than laces here. I switched to elastic laces and it cut my transition time by roughly forty-five seconds.

The Brick

A brick is a bike-to-run session, and it's essential. Your legs feel like concrete after you get off the bike. This is a neurological thing, not just fatigue. Your body has learned to fire muscles in a cycling pattern, and switching to running feels wrong. You have to retrain that sensation. Do bricks at least once a week during base training. Start with twenty minutes on the bike followed by ten minutes on the run. Build from there. The run after the bike should be short and controlled. You're not trying to go fast; you're trying to teach your nervous system that running is still an option. After six to eight weeks of bricks, that concrete feeling starts to disappear. My first brick where my legs felt normal was around week seven. Before that, I felt like I was running on stilts.

Volume Building

A triathlon training plan typically runs twelve to sixteen weeks depending on your starting fitness and the race distance. For a sprint (750m swim, 20km bike, 5k run), you need maybe eight to twelve weeks of focused work. An Olympic distance (1.5km swim, 40km bike, 10k run) needs twelve to fourteen weeks. Half Ironman requires sixteen to twenty weeks. Full Ironman is where it gets serious, usually twenty-four weeks or more. The key principle is progressive overload. Increase your total weekly volume by no more than ten percent per week. If you're doing ten hours this week, do eleven next week. If you jump from ten to fifteen, something breaks. Usually it's your Achilles or your lower back. I learned this the hard way during an Ironman prep cycle. I increased my volume by thirty percent in a single week because I had a vacation booked and thought I could cram training in. Result: stress fracture in my right foot, six weeks sidelined.

Recovery Is Training

You don't get fitter when you train. You get fitter when you recover from training. The workout is just the stimulus. If you're not sleeping seven to eight hours, if you're not eating enough carbohydrates around your sessions, if you're ignoring nagging pains, none of the volume in the world will help you. I've watched too many people ignore a twinge in their shoulder for three weeks, then blow out their rotator cuff two weeks before the race. It happens constantly. When something hurts during a session, modify or stop. Don't power through. A modified session beats no session. A rest day beats a stress fracture.

Nutrition During Training

This gets ignored until race day, and then it's too late to figure out. You need to practice eating while you ride and while you run. Your gut is a muscle too. Start with thirty grams of carbohydrates per hour during sessions under ninety minutes. Work up to sixty grams per hour for longer efforts. Gels, chews, bars, sports drink — whatever works, but only after you've tested it in training. I used to race without any fuel because I assumed a sprint wasn't long enough. Then at my second sprint, I bonked hard at kilometer three of the run. Felt like my brain had shut down. Now I take two gels during a sprint. Thirty minutes into the bike, another ten minutes before the run starts. Simple, and it made the difference between a DNF and a top-three finish that day.

Common Pitfalls

Don't skip the swim. Swimmers who can't swim efficiently will walk into the run exhausted before they even start. Even if swimming is your weakest discipline, don't avoid it. It's the first segment. Every other segment depends on it. Don't obsess over gear. Your first triathlon doesn't need a $4,000 bike and carbon wheels. A decent road bike, a wetsuit that fits, and proper shoes will get you across the finish line. I coached someone who bought an aero bike three weeks before their first Olympic distance race. They couldn't even get the geometry right and rode painfully slow because they weren't adapted to the position. Old bike, correct fit, faster time. Don't underestimate the mental game. Three hours or three days on a bike with sand in your eyes, your face stinging from sweat, and legs that have been in one position for hours — that's not physically hard, it's mentally draining. Practice long sessions. The discomfort becomes normal after a while.

Sample Week (Olympic Distance Build Phase)

Monday: Rest or easy 30-minute walk Tuesday: Swim 2km main set with drills, 3x400m at race pace. Bike 45 minutes easy with 4x5 minutes threshold efforts. Wednesday: Run 8km easy, includes 6x1-minute strides

Thursday: Swim 2.5km, technique focus. Brick: 40 minutes bike into 6km run. Friday: Rest Saturday: Long bike 1.5 to 2 hours, steady effort. Finish with 10 minutes run.

Sunday: Long run 12 to 14km, conversational pace. If training for longer distances, extend this to 16 to 18km. That's roughly ten to twelve hours of work. For a half Ironman build, you'd scale each session up proportionally and add another brick and a longer run. The structure stays the same. Get a power meter or at least a heart rate monitor. Garmins and Wahoo units aren't expensive anymore and they prevent exactly the problem I described earlier — going out too hard on the bike and paying for it on the run. If your heart rate is spiking on the bike and staying high for twenty minutes after you mount, you've gone out too hard. Easy fix with data. Impossible fix once you're on race day with no feedback.

There's no shortcut. The training is what it is. But it's not complicated. Swim well enough, bike efficiently, run consistently, and don't do anything new on race day. Everything else is noise.