The Strength Phase for Runners: Power and Prevention

The Problem I See Every Season

A runner comes to me with a familiar history: solid mileage, well-executed intervals, and a recurring injury that shows up every time volume increases. Almost always, the same piece is missing from their plan: structured strength training, with real progression — not "a little core work on Tuesdays."

Strength training for runners isn't a cosmetic accessory or an Instagram trend. It's a tool with clear physiological mechanisms that directly affect two things all of us care about: how much oxygen we burn to hold a given pace, and how resilient our tissues are when volume climbs.

What the Evidence Says About Running Economy

Running economy — the oxygen cost of sustaining a submaximal speed — is one of the strongest predictors of distance running performance, alongside VO2max and lactate threshold. The relevant question isn't whether strength matters, but how much, what type, and at what point in the cycle.

A recent systematic review with meta-analysis examined the effect of different strength programs on running economy at various speeds in middle- and long-distance runners [PMID:38165636]. The central finding: strength training consistently improves running economy, and that effect holds across different test speeds, not just at easy paces. This matters because many runners assume strength only helps with the final sprint; in reality, the benefit shows up at distance-running intensities too.

The likely mechanism isn't massive muscle hypertrophy — nobody becomes a better distance runner by lifting like a powerlifter — but neuromuscular adaptations: better motor unit recruitment, greater musculotendinous stiffness, and more efficient use of the stretch-shortening cycle with every stride. Running, at its core, is a repeated series of elastic bounces. A stronger neuromuscular system absorbs and returns that energy with less metabolic waste.

Fatigue Changes the Equation

This is where many strength programs fall short: they measure running economy in a fresh state, but races are decided when the body is already fatigued.

A recent randomized controlled trial in well-trained runners looked specifically at this: what happens to running economy and high-intensity performance when the athlete is already fatigued, after incorporating a strength block [PMID:40016936]. The results showed that strength training doesn't just improve running economy overall — it improves its durability, meaning how well that efficiency holds up when the body has already accumulated kilometers of fatigue. It also improved high-intensity performance carried out in a fatigued state.

This is huge for anyone racing half marathons, marathons, or even competitive 10Ks. Running economy at kilometer 3 isn't what decides the race. What decides it is your economy at kilometer 30, when fast-twitch fibers start to fail and the body relies on compensatory recruitment. A neuromuscular system trained for strength has more reserves for that moment.

Prevention: The Less Glamorous but Equally Important Reason

Strength doesn't just make the fatigued runner faster — it also lowers the odds that runner ends up on the sidelines. Tendons, ligaments, and bone structures adapt more slowly than the cardiovascular system. An athlete can have the VO2max of a national-level runner and still break down because of a weak hip or an Achilles tendon that never received progressive load.

This mismatch between aerobic capacity and structural capacity is, in my experience working with masters runners, the number one cause of interrupted seasons. It's not cardiovascular overtraining — it's structural undertraining.

Well-programmed strength work — unilateral movements, hip patterns, ankle stability, eccentric strength for quads and hamstrings — builds the tissue resilience that running volume alone can't generate with the same efficiency or safety.

The Heart Also Enters the Conversation

When we talk about "prevention" for endurance runners, we almost always think of tendons and joints. But there's another organ working under sustained load: the heart. A recent analysis on the cardiac effects of prolonged endurance exercise in young and older athletes notes that high, sustained volumes of aerobic training produce cardiac adaptations that are generally beneficial, but that require particular attention in masters athletes, where the margin for recovery and cardiac remodeling differs from that of a younger athlete [PMID:40667749].

This doesn't mean strength training replaces aerobic work — not at all — but it reinforces a principle I apply with my masters athletes: a balanced training approach, where strength reduces the exclusive reliance on aerobic volume to drive performance, also protects the long-term cardiovascular variable. Needing less accumulation of extreme mileage to progress means less chronic stress on a system that, with age, adapts and recovers differently.

How to Structure the Phase: Practical Principles

There's no need to reinvent the wheel. The evidence points to clear principles, and applying them requires coaching judgment so the work doesn't collide with aerobic training.

1. Frequency: 2 sessions per week, no more. Most studies showing improvements in running economy use protocols of 2 sessions per week, over 6 to 12 weeks [PMID:38165636]. Three sessions compete for recovery resources with quality workouts. Two well-executed sessions beat three poorly digested ones.

2. Heavy loads, low reps. The goal isn't hypertrophy. We work in ranges of 3 to 6 reps at 80-90% of one-rep max on basic movements: squat, Romanian deadlift, single-leg press, hip thrust. Moderate-to-heavy loads with low reps produce the neuromuscular adaptations that improve musculotendinous stiffness without adding mass that penalizes the power-to-weight ratio.

3. Dosed plyometrics. Jumps, weighted skipping, and reactive drills complement maximal strength work. This is where the stretch-shortening cycle — which explains much of the improvement in running economy — gets trained directly.

4. Unilateral and eccentric work as a prevention priority. Lunges, step-ups, and eccentric work for the gastrocnemius and hamstrings directly target the most common injury patterns in runners: plantar fasciitis, Achilles tendinopathy, patellofemoral pain syndrome.

5. Calendar placement: off-season and base phase, not at the peak. The most intense strength phase (heavier loads, higher set volume) belongs in the base and general-build mesocycle, typically 8 to 12 weeks before the target race. As the race approaches, strength volume gets reduced but frequency is maintained with maintenance loads — it's never eliminated entirely, just adjusted in dose.

Nutrition Is Not a Minor Detail in This Phase

Adding strength work to the plan means more total stress on the system, and that demands attention to protein intake and total energy. Contemporary nutrition strategies for distance runners emphasize the importance of adequate energy availability and protein timing to support both aerobic and neuromuscular adaptation [PMID:30747558]. A runner who adds two weekly strength sessions without adjusting caloric and protein intake is building on sand.

A Note for Runners in the Perimenopause Transition

For women runners in the perimenopause stage, the strength phase takes on extra relevance. Research describes perimenopause as a systemic inflammatory phase linked to changes in metabolism, body composition, and musculoskeletal health [PMID:33097048]. In practice, this translates into a higher risk of muscle mass and bone density loss if a strength stimulus isn't present. In my work with female masters athletes, the strength phase stops being optional at this stage of life — it becomes a long-term protective tool, not just a performance one.

What I Take Away From All This

Strength doesn't compete with aerobic work — it powers it and protects it. The evidence is clear on two fronts: it improves running economy, even in a fatigued state [PMID:38165636][PMID:40016936], and it builds the structural resilience that prevents the injuries that interrupt seasons. Two well-dosed weekly sessions, with real load progression, is the highest-return time investment a serious runner can make outside of running itself.

This isn't about becoming a weightlifter. It's about giving the body the tools to sustain the effort that aerobic training demands — kilometer after kilometer, season after season.

References

• Llanos-Lagos C, Ramirez-Campillo R, et al. Effect of Strength Training Programs in Middle- and Long-Distance Runners' Economy at Different Running Speeds: A Systematic Review with Meta-analysis. Sports Med. 2024. [PMID:38165636]
• Zanini M, Folland JP, et al. Strength Training Improves Running Economy Durability and Fatigued High-Intensity Performance in Well-Trained Male Runners: A Randomized Control Trial. Med Sci Sports Exerc. 2025. [PMID:40016936]
• Frandsen J, Aaroe M, et al. Cardiac Effects of Prolonged Endurance Exercise in Young and Older Athletes. Scand J Med Sci Sports. 2025. [PMID:40667749]
• Burke LM, Jeukendrup AE, et al. Contemporary Nutrition Strategies to Optimize Performance in Distance Runners and Race Walkers. Int J Sport Nutr Exerc Metab. 2019. [PMID:30747558]
• McCarthy M, Raval AP. The peri-menopause in a woman's life: a systemic inflammatory phase that enables later neurodegenerative disease. J Neuroinflammation. 2020. [PMID:33097048]