What Does It Take to Run a Marathon?

A marathon is 26.2 miles. That number gets thrown around casually, but most people don't grasp what it actually demands from the human body.

During those miles, your feet strike the ground roughly 40,000 times. Each impact sends 2-3 times your body weight through your legs. Your muscles burn through their glycogen stores and eventually start breaking down their own tissue for fuel. Your cardiovascular system works at elevated output for 3, 4, sometimes 5+ hours straight.

This isn't a long jog. It's a serious endurance event that tests the structural limits of your body.

The Injury Problem

Approximately 50% of first-time marathoners get injured during training.

Not during the race. During training. Before they even reach the start line.

This isn't because beginners are weak or undisciplined. It's because marathon training demands more from the body than most people realize — and running alone won't prepare you for it.

Every run creates micro-damage in muscles, tendons, and bones. Normally, the body repairs this damage and comes back stronger. But marathon training requires high mileage over many months. That's a lot of accumulated stress on the same tissues, loaded the same way, over and over.

Without supplemental work, fitness builds on a foundation that's slowly cracking. The 50% injury rate isn't bad luck. It's the predictable result of incomplete preparation.

What Actually Protects the Body

Marathon training isn't just running. It's building a body that can handle 26.2 miles without falling apart.

Strength Training

Muscles are the primary shock absorbers for every foot strike. Weak glutes force the knees to take excess load. Weak calves lead to Achilles problems. A weak core transfers stress to the lower back.

Heavy, low-rep strength work — particularly targeting the posterior chain (glutes, hamstrings, calves) — builds the force capacity and tendon stiffness that running alone can't provide. Stronger muscles fatigue slower. Stiffer tendons return more elastic energy with each stride.

Two sessions per week, 20-30 minutes each. This is the minimum for anyone serious about finishing healthy.

Mobility Work

Running is repetitive. Same motion, same range, thousands of times per week. Over months, this creates tightness and restrictions that limit movement and transfer stress to vulnerable areas.

Mobility work keeps joints moving through their full range. Hips, ankles, and thoracic spine matter most for runners. Dynamic mobility before runs prepares the body for the session. Active mobility on easy days maintains tissue quality.

8-12 minutes daily. This isn't stretching for flexibility's sake. It's maintaining the movement quality that prevents compensation patterns.

Running Drills

Running form degrades under fatigue. What starts as an efficient stride at mile 3 becomes a shuffle by mile 20. Drills reinforce the neuromuscular patterns that maintain form when everything else is breaking down.

A-skips develop hip drive. Quick feet drills improve cadence. Strides build economy at faster speeds. These aren't just warm-up fillers — they teach the nervous system how to run efficiently, so good form stays automatic even under exhaustion.

2-4 sessions per week, 8-12 minutes each. Usually as part of a pre-run warm-up.

Cross-Training

Sometimes the best thing for running is not running. Cross-training — cycling, swimming, elliptical — builds aerobic capacity without impact stress.

This allows more total training volume while giving running-specific tissues a break. It's load management, not fitness chasing. The value is in the low-stress aerobic stimulus.

1-2 sessions per week, kept easy.

Running Economy: Why Small Things Multiply

Running economy is how much energy the body uses at a given pace. Two runners with identical VO2max can have very different marathon times based on economy alone. The efficient runner burns less fuel per mile, leaving more in reserve for the final miles.

Small differences in economy multiply over 26.2 miles.

Wasting 5% more energy per stride due to weak glutes, poor form, or limited hip mobility doesn't mean a 5% harder marathon. It means hitting the wall earlier. It means form collapsing when it matters most. It might mean not finishing at all.

Strength training improves economy by increasing force production and tendon stiffness. Mobility work improves economy by allowing fuller range of motion without restriction. Drills improve economy by ingraining efficient movement patterns.

More miles build fitness. Supplemental work makes each mile cost less.

The Real Commitment

Training for a marathon requires:

• Running 4-5 days per week, including a weekly long run
• 2 strength sessions per week (20-30 minutes each)
• Daily mobility work (8-12 minutes)
• Running drills 2-4 times per week (8-12 minutes, often as warm-up)
• 1-2 cross-training sessions per week

This isn't about doing more for the sake of more. It's about building a body that can absorb training stress, maintain efficiency under fatigue, and arrive at the start line healthy and prepared.

A marathon is a serious undertaking. Those who treat it that way finish strong. Those who cut corners become part of the 50%.