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PlanB Coaching > Blog > Uncategorized > The best strength exercises for swimming in triathlon
The swim leg of a triathlon is often where age group athletes lose the most time relative to their peers, and it is rarely because they haven’t spent enough hours staring at a black line. It is frequently a force production problem. You can have flawless technique, but if the muscles responsible for moving water backwards lack the strength to sustain that pull for 1,500 metres or more, your stroke will decay, your shoulders will fatigue, and your bike and run will suffer as a result.
In the UK, the conversation around strength work for triathletes and swimming has shifted considerably in recent years. The old fear of “bulking up” and carrying unnecessary muscle around a 10k run has largely been replaced by a more nuanced understanding. The right kind of strength training improves economy, durability, and injury resilience without adding dead weight. For the swim specifically, this means moving away from endless high rep, light weight circuits and embracing a philosophy of heavy, low-repetition, compound movements that target the primary movers of the pull.
Before listing the exercises, it is crucial to understand the “why.” A common mistake triathletes make is treating the gym like an extension of the pool, performing sets of fifteen or twenty repetitions on machines. As strength coach Dan Daly points out, this is a fundamental misunderstanding of what the gym is for . Endurance athletes often think they need to train endurance in the gym, but high-rep work primarily drives muscular endurance and hypertrophy (muscle growth)—neither of which is the primary goal for a swimmer who already logs thousands of metres in the water .
The goal in the gym is to improve your nervous system’s ability to produce force rapidly. This means lifting relatively heavy loads for low repetitions—typically in the three-to-six rep range—with full recovery between sets . This approach trains the neuromuscular system to fire harder and faster, which translates directly to a more powerful catch and pull in the water. It also produces less soreness and takes less time, which matters when you are balancing swim, bike, and run sessions .
If you only had time for one exercise to improve your swim, almost every coach would tell you to strengthen your lats. The latissimus dorsi is the largest muscle in your upper body and the primary driver of the freestyle pull. It is the engine that moves you through the water.
The Pull-Up (and Its Regressions)
The pull-up is widely regarded as the gold standard for lat development and swim-specific strength . It trains the exact overhead pulling pattern you use in the water. However, many triathletes cannot perform an unassisted bodyweight pull-up. This is not an excuse to skip it. The solution is to find an entry point: use a band for assistance, use an assisted pull-up machine, or perform negatives (jumping up to the top and lowering yourself slowly) .
When performing pull-ups, focus on a full range of motion. Pause at the bottom with your arms fully extended; there is no elastic recoil in the water, so you should not bounce out of the bottom position . If you have shoulder mobility restrictions, a horizontal row (such as a seated cable row or a dumbbell row) is a legitimate starting point, but the long-term goal should be to get overhead .
The Lat Pulldown
For those who need to build strength before progressing to bodyweight pull-ups, the lat pulldown is an effective tool. The key is to use a full range of motion, bringing the bar from overhead down to your chest, and to avoid leaning back excessively. Think of it as a vertical pull, not a row . Wide-grip variations are particularly useful for emphasising the lats .
A powerful lat is useless if the shoulder joint is unstable or the core cannot transfer force from the lower body to the upper body. In the UK, physiotherapists and S&C coaches place heavy emphasis on anti-rotation and anti-extension core work, as well as scapular stability.
The Plank and Its Variations
The plank is an isometric exercise that strengthens the stabilising muscles of the shoulders, trunk, and hips against gravity . For swimming, it teaches you to maintain a rigid, streamlined position while your limbs are moving. A standard front plank is a starting point, but the real benefits come from dynamic variations. The “Plank and Pull” (maintaining a push-up position while performing a one-arm dumbbell row) is a challenging swim-specific exercise that builds lat strength and anti-rotation stability simultaneously . Side planks are also essential for targeting the obliques, which help you rotate efficiently in the water .
Scapular Stability: Press and Sweep
Without adequate scapular stability, you lack a stable anchor for your lats to pull against, and you are far more injury-prone . Exercises that challenge your ability to control your shoulder blades through a variety of angles are invaluable. The “Press and Sweep” involves keeping your shoulder blades down and back while your arms move, maintaining a solid squeeze between them . This is particularly relevant for triathletes, who spend hours in a rounded-shoulder position on the bike, which can compromise swim posture.
While pull-ups are the king of vertical pulling, horizontal pulling exercises are equally important for balancing the shoulders and building the muscles of the upper back (rhomboids, trapezius, rear deltoids) that support the pull.
The Seated Cable Row
This is a staple in almost every triathlete’s strength programme. It targets the mid-back and helps correct the postural imbalances created by cycling. Focus on squeezing your shoulder blades together at the point of contraction, and avoid using momentum by rocking your torso .
The Dumbbell Reverse Fly
This exercise targets the posterior deltoids and the upper back, which are crucial for shoulder health and stability. It is a light-weight, high-control movement. Perform it with a slight bend in the elbows, focusing on the squeeze between your shoulder blades rather than lifting the weight high .
While not strictly a swim-specific exercise, the Turkish Get-Up is a favourite among UK S&C coaches for triathletes because it teaches whole-body integration, shoulder stability, and core control under load. It requires you to move from lying to standing while holding a weight overhead, challenging every joint in the body to work in coordination. For a swimmer, this translates to better body awareness and the ability to maintain a strong, stable line in the water, even when fatigued.
The consensus among UK-based coaches is that two full-body strength sessions per week are sufficient for most age-group triathletes during the off-season and base phases . During the race season, this can be reduced to one short maintenance session per week .
The most critical rule is to avoid compromising your key endurance sessions. Do not schedule a heavy lower-body lifting session in the 24 to 48 hours before your hardest run or bike intervals. A sensible approach is to place strength work after an easier swim or bike day, or on a day where the following session is low intensity .
A simple, effective session structure for a swim-focused strength block might look like this:
Pull-Ups (or Lat Pulldowns): 3 sets of 3-6 reps.
Seated Cable Row: 3 sets of 6-8 reps.
Plank and Pull: 3 sets of 6-8 reps per arm.
Dumbbell Reverse Fly: 3 sets of 10-12 reps.
Side Plank: 3 sets of 30-45 seconds per side.
The best strength exercises for swimming in triathlon are not complicated, but they require a shift in mindset. Stop chasing the burn with high-rep sets. Start chasing force production with heavy, controlled pulls. Prioritise the lats, stabilise the shoulders, and brace the core. Do this consistently, and you will find that the water gives way more easily, your stroke holds together longer, and you arrive at T1 with more energy for the bike and run. As the saying goes in UK training circles, you don’t win the race in the gym, but you can certainly lose it by neglecting it.
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