As marathon mileage rises, the usual problem is not knowing that strength training helps. It is fitting useful work around long runs, tempo sessions, and recovery without showing up to key runs with heavy, sore legs. A one strength workout a week for marathon runners can maintain the qualities that matter most: single-leg control, posterior-chain strength, calf capacity, and trunk stability.
The goal is not to chase personal records in the weight room during a marathon block. The goal is to make running feel more resilient while keeping fatigue low enough to complete the sessions that actually drive marathon fitness.
Quick Answer
For most marathon trainees, one full-body strength session per week is enough to maintain strength and running-specific durability when mileage is high. Put it after an easy run or on the same day as a harder workout, rather than the day before a long run, interval session, or tempo run.
Build the session around five movements: a split squat, step-up, Romanian deadlift (RDL), calf raise, and core exercise. Use moderate loads, stop with one to three good reps left, and keep the entire session to 35 to 55 minutes.
A practical rule is simple: strength work should leave you feeling trained, not trashed. If it changes your running stride, delays recovery for more than 48 hours, or makes your next key session worse, reduce the lifting volume before reducing your marathon running.
Why This Happens
Marathon training already places a large demand on the legs. Weekly long runs challenge muscular endurance, workouts add higher-force running, and easy mileage accumulates repetitive loading through the feet, calves, knees, hips, and trunk. A traditional gym plan with multiple lower-body days can add fatigue faster than it adds useful adaptation.
The issue is often delayed-onset muscle soreness, especially from unfamiliar eccentric work. Deep lunges, heavy RDLs, step-ups, and slow lowering phases can make the glutes, quads, hamstrings, and calves sore for two or three days. That soreness is not proof of an effective marathon strength workout. It may simply mean the dose was more than your current running schedule can absorb.
At the same time, skipping strength entirely can leave a gap. Running builds impressive endurance, but it does not always maintain the same level of force production, single-leg control, or calf and foot capacity that helps runners tolerate changing terrain, hills, faster sessions, and late-race fatigue.
One well-designed weekly session works because it gives the body a regular strength signal without repeatedly competing with run recovery. The best exercises also have a clear transfer to running positions: one leg supports the body, the hip extends behind you, the calf handles load, and the trunk resists unnecessary movement.
Step-by-Step Method
1. Choose the right day
Place strength on an easy-run day, ideally after the run, or later on the same day as intervals or a tempo workout. This groups your stress instead of spreading leg fatigue across every day of the week.
For example, if your quality workout is Tuesday and your long run is Sunday, lift after Tuesday’s workout or after an easy Wednesday run if you usually recover well. Avoid lifting hard on Friday or Saturday if Sunday is your long run.
If you are new to lifting, the best day is the day that leaves at least 48 hours before your most important run. Consistency matters more than finding a theoretically perfect slot.
2. Warm up without turning it into another workout
Spend five to eight minutes preparing. Walk, cycle easily, or jog if you have not already run. Then do one light set of bodyweight split squats, hip hinges, calf raises, and a few controlled leg swings.
Do not use a long, exhausting circuit. You need enough preparation to move well, not enough to create fatigue before the working sets begin.
3. Start with a single-leg knee-dominant exercise
Use Bulgarian split squats, regular split squats, or reverse lunges. These train the quads, glutes, and hip control in a position that resembles the single-leg demands of running.
Perform 2 to 3 sets of 6 to 10 repetitions per side. Start with body weight or dumbbells. Lower under control, keep the front foot fully planted, and use a range of motion you can control without hip twisting or knee pain.
4. Add step-ups for running-specific control
Step-ups are useful because they combine hip drive with balance and a controlled landing. Choose a box height that allows you to keep your pelvis level and push through the working foot. Do not bounce off the trailing foot.
Perform 2 sets of 6 to 8 repetitions per side. Keep the load modest. If step-ups make your knees ache or feel unstable, lower the box height, slow the movement, or use split squats instead.
5. Train the posterior chain with RDLs
Romanian deadlifts target the hamstrings and glutes while teaching a controlled hip hinge. Dumbbells are often easier to manage than a barbell during a high-mileage block because they allow a comfortable range of motion and less setup.
Perform 2 to 3 sets of 6 to 10 repetitions. Keep a soft bend in the knees, move the hips backward, and stop when your hamstrings are loaded but your back position remains neutral. This is not a test of how far the weights travel toward the floor.
6. Do calf raises with intent
The calves and Achilles complex absorb and return force on every stride. They deserve direct work, especially if you run hills, wear low-drop shoes, or have added mileage recently.
Perform 2 to 3 sets of 8 to 15 standing calf raises, using a wall or rack for balance. Pause briefly at the top and lower slowly. If you tolerate it well, include one set with a bent knee to involve the soleus muscle, which is heavily used in distance running.
7. Finish with anti-rotation or anti-extension core work
Choose a dead bug, front plank, side plank, Pallof press, or suitcase carry. The purpose is not visible abdominal fatigue. It is maintaining trunk control while the legs work beneath you.
Do 2 sets. For planks, use 20 to 45 seconds of high-quality tension. For carries, walk 20 to 40 meters per side with a weight that challenges posture without making you lean.
8. Keep the effort submaximal
Use a load that feels like an effort of roughly 6 to 8 out of 10. You should finish most sets with one to three repetitions in reserve. Avoid grinding reps, testing maxes, and adding burnout sets during the main marathon build.
Progress slowly. Add one or two repetitions, a small amount of weight, or an extra set only when the previous session did not compromise your running.
Common Mistakes
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Lifting to failure because the session is only once per week. One weekly session does not need to be punishing to be productive. Stop with clean reps still available, then return next week able to run well.
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Doing the workout the day before the long run. Heavy split squats and RDLs can make the long run feel flat or change mechanics. Put strength after a hard day or farther from your longest run.
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Adding too many exercises. A long list of machines, jumps, isolation work, and finishers turns a maintenance session into a second leg day. Keep the core five movements and use good technique.
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Increasing load and mileage in the same week. New gym volume plus a new running peak is a common recipe for lingering soreness. Progress one stressor at a time whenever possible.
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Ignoring calf work because squats feel more important. Calves receive enormous repetitive loading in marathon training. Controlled calf raises are often a better use of limited gym time than extra quad work.
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Copying a powerlifting plan. Heavy low-rep barbell work can suit experienced lifters, but it is not automatically the best choice during a marathon block. Choose exercises you can recover from and repeat consistently.
Checklist or Decision Table
| Situation | Best adjustment | What to avoid |
|---|---|---|
| You are new to strength training | Start with 2 sets per exercise and body weight or light dumbbells | Heavy RDLs, deep soreness, adding plyometrics immediately |
| Your long run is within 24 hours | Move strength earlier in the week or do only light core and calf work | Split squats and RDLs to hard effort |
| You have a hard Tuesday workout | Lift after that workout or later that day if practical | Putting lifting on Monday night |
| Your legs stay sore for 48+ hours | Remove one set from split squats and RDLs | Assuming soreness means progress |
| You are in the final 2-3 weeks before the marathon | Maintain familiar light-to-moderate work, then reduce volume | New exercises, max lifts, high-rep leg circuits |
| You have limited time | Do split squats, RDLs, calf raises, and side planks | Skipping the entire session because 60 minutes is unavailable |
When This Advice Does Not Apply
This template is designed for generally healthy runners who are already building toward a marathon and want a simple maintenance-focused gym session. It is not a rehabilitation plan for a current injury, nor is it a complete strength program for an off-season athlete whose main goal is maximal strength or muscle gain.
If you have persistent pain, swelling, numbness, weakness, or pain that changes your running gait, do not try to solve it by pushing through more split squats or calf raises. A qualified sports clinician or physiotherapist can assess the issue and tailor loading appropriately.
You may also need a different approach if you are a complete beginner, returning after a long break, or running very low mileage. In those cases, two short sessions can sometimes be easier to learn and recover from than one larger workout. During peak marathon weeks and taper, reduce volume first. Maintaining movement quality matters more than gaining strength at that point.
Realistic Example
Consider a runner training for a first marathon on four run days per week: Tuesday intervals, Thursday easy running, Saturday tempo running, and Sunday long running. They had been doing a full lower-body gym workout on Friday, then wondering why Saturday’s tempo felt sluggish and Sunday’s long run began with stiff quads.
A better setup is lifting after Tuesday intervals. The runner completes two sets of dumbbell split squats, two sets of step-ups, two sets of RDLs, two sets of calf raises, and two sets of side planks. The session takes about 40 minutes. They use loads that feel challenging but leave two repetitions in reserve.
For the first two weeks, their only goal is to finish without prolonged soreness. In week three, they add a small amount of weight to the split squats and RDLs. When marathon mileage peaks, they keep the same exercises but drop to two sets each. Their strength work remains consistent, while Thursday, Saturday, and Sunday runs stay protected.
Final Takeaway
The best one-session-per-week strength workout for marathon runners is short, repeatable, and built around single-leg strength, hip hinging, calf capacity, and trunk control. Put it where it will not damage your important running sessions, keep one to three reps in reserve, and reduce lifting volume whenever recovery starts slipping.
Think of gym work as support for marathon training, not a separate competition. If the workout helps you run with better control and does not make your key sessions worse, the dose is probably right.
FAQs
Should marathon runners lift once or twice a week during peak mileage?
Yes, once per week can be enough during peak marathon mileage when the session is focused and consistent. A second short session may work for experienced runners who recover well, but it is not required to maintain useful strength. Start with one session built around split squats, RDLs, calf raises, and core work. Add a second session only if your sleep, easy-run pace, soreness, and key workouts remain stable for several weeks. During a demanding marathon block, protecting quality runs is usually more valuable than adding gym volume.
When should I do strength training before a marathon long run?
Ideally, do not perform a demanding lower-body strength workout within 24 hours of a marathon long run. Split squats, step-ups, and RDLs can leave the legs sore or neurologically fatigued, which may alter stride quality on the long run. Put your main strength session after intervals or a tempo session earlier in the week, or allow at least 48 hours before the long run. If scheduling forces you to lift the day before, keep it very light and limit the session to mobility, easy calf work, and core stability.
How many sets of split squats should marathon runners do?
Most marathon runners should do two to three sets of six to ten split squats per leg in a once-weekly strength session. Two sets are a smart starting point if you are new to the movement, increasing mileage, or prone to post-lifting soreness. Use a load that allows controlled balance and leaves one to three reps in reserve. More is not automatically better: if split squats make your next speed session or long run worse, reduce the sets, range of motion, or load before abandoning the exercise.
Are Romanian deadlifts good for marathon runners?
Yes, Romanian deadlifts are useful for marathon runners because they strengthen the hamstrings and glutes through a controlled hip-hinge pattern. They can help maintain posterior-chain strength that running alone may not fully develop. Use dumbbells or a barbell only if you can maintain a stable back position and feel the work primarily in the hamstrings and glutes. Two or three moderate sets are enough for most runners. Avoid pushing RDLs to failure, especially during high-mileage weeks, because hamstring soreness can interfere with stride comfort.
Should I do heavy calf raises while training for a marathon?
Yes, calf raises can be loaded during marathon training, but they should be progressed gradually. The calves already handle substantial work from running, hills, and faster sessions, so a sudden jump in weight or volume can create unnecessary soreness. Begin with two sets of eight to fifteen controlled repetitions and lower slowly. Add load only when your calves recover normally and your running feels unchanged. If you have recent Achilles or calf pain, avoid aggressively increasing loading and consider individualized guidance from a qualified clinician.
Should I stop strength training during the marathon taper?
No, you usually do not need to stop strength training completely during the marathon taper. Keep familiar exercises but reduce the total amount of work, especially in the final seven to ten days. For example, use one or two easy sets instead of three, avoid new exercises, and do not chase heavier weights. The goal is to maintain coordination and confidence without creating soreness. If you know that even light lifting makes your legs feel heavy, finish your last lower-body session earlier and keep only gentle mobility and core work near race day.