Prevention > Cure
Did you know? Between 37 and 56% of runners get injured each year - and a cohort of 1,680 runners followed for 12 months found that 48% sustained at least one running-related injury (Walter et al., 1989 ; van Mechelen, 1992). Most of these injuries can be avoided with targeted strength work and appropriate progression.
The most common injuries in runners
According to running injury experts and scientific studies, here is the "Top 5" of running injuries:
- Patellofemoral pain syndrome (anterior knee pain) - 20-25%
- Achilles tendinopathy - 10-15%
- Medial tibial stress syndrome (shin splints) - 10-15%
- Iliotibial band syndrome - 8-12%
- Plantar fasciitis - 8-10%
Good news: targeted strength training reduces these risks by 30 to 50%.
1. Patellofemoral pain syndrome: protect your knees
What is it?
Patellofemoral pain syndrome (PFPS) is diffuse pain at the front of the knee, around or behind the kneecap. It often appears when going down stairs, sitting for a long time, or running uphill/downhill.
💪 Strength as Protection
Stronger muscles = a more resilient runner. Strengthening the quadriceps and glutes and improving neuromuscular control considerably reduces the risk of knee pathologies. Muscular strength acts as a protective shield for the joint.
Main causes
- Quadriceps weakness (especially vastus medialis): The kneecap "drifts" laterally instead of gliding straight in its groove
- Weak gluteus medius and minimus: The pelvis drops, and the knee moves inward (valgus)
- Muscular imbalance: Hamstrings too stiff relative to quadriceps
- Training volume increased too quickly: The tissues do not have time to adapt
Prevention exercises
A. Step down
Why: Strengthens the quadriceps (vastus medialis) and glutes, improves knee neuromuscular control, and reduces valgus (knee collapsing inward). This exercise is scientifically validated for preventing patellofemoral pain syndrome.
Execution:
- Stand on a step (10-20 cm high), left leg hanging off
- Slowly lower the left heel toward the ground (3-4 seconds)
- Lightly touch the ground with the left heel
- Rise by pushing through the right leg (support leg)
- Repeat 12-15 times per leg, 3 sets
Key Point: The support-leg knee must NOT collapse inward. Keep it aligned with the 2nd toe.
B. Isometric wall sit
Why: Builds quadriceps muscular endurance in an isometric position. Essential for maintaining knee stability over long distances and reducing joint fatigue.
Execution:
- Back against a wall, feet 40-50 cm from the wall
- Lower until thighs are parallel to the ground (90° knee angle)
- Hold the position for 30 seconds to 2 minutes
- Repeat 3-4 times
Progression: Start at 30 sec, add 10 sec each week.
C. Clamshells
Why: Targets gluteus medius and minimus, essential muscles for stabilizing the pelvis and preventing valgus.
Execution:
- Lie on your side, knees bent at 90°, feet together
- Open the top knee toward the sky (like a clam opening)
- Keep the feet together, do not lift the pelvis off the ground
- Hold 2 seconds at the top, lower under control
- 15-20 repetitions per side, 3 sets
Variation: Add a resistance band around the knees for more resistance.
2. Achilles tendinopathy: strengthen your calves and tendons
What is it?
Achilles tendinopathy is inflammation (or degeneration) of the Achilles tendon, which connects the calf to the heel. Typical pain: morning stiffness, pain when starting that eases during warm-up, then returns late in the run.
Main causes
- Sudden overload: Increasing volume (mileage) or intensity (intervals) too quickly
- Lack of calf strength and tendon stiffness: The tendon is not strong enough to absorb repeated shocks and return elastic energy
- Calf stiffness: Limited ankle range of motion
- Unsuitable shoes: Drop (heel-to-toe difference) too low without gradual adaptation
💡 The Secret of Tendon Stiffness
Calf strengthening does not only train the muscle: it also strengthens the Achilles tendon. Eccentric exercises (controlled lowering over 3-5 seconds) and plyometrics (jumps, jump rope) increase tendon stiffness by up to 16% in 14 weeks. A stiffer tendon stores and returns elastic energy better at every stride, like a more powerful spring.
Prevention exercises
A. Drop down (Achilles tendon eccentric)
Why: Eccentric work (resisting the muscle's stretch) is THE scientifically validated protocol for strengthening the Achilles tendon and increasing its stiffness. This adaptation makes the tendon more robust against repeated running loads.
Execution:
- Stand on a step, forefeet on the step, heels hanging off
- Rise onto the toes (both feet)
- Lift one foot (non-working leg)
- SLOWLY lower the heel below step level (eccentric phase, 3-5 seconds)
- Rise back up with both feet
- Repeat 12-15 times per leg, 3 sets
Alfredson protocol: 2 variations per session: straight knee (gastrocnemius) and bent knee (soleus). Do EVERY DAY for 12 weeks for a curative effect.
B. Calf raises
Why: Builds concentric calf strength and muscular endurance. An essential complement to eccentric work for full strengthening of the calf-tendon complex.
Execution:
- Stand with feet hip-width apart
- Rise onto the toes (maximal contraction at the top)
- Hold 1 second
- Lower under control
- 15-20 repetitions, 3 sets
Variations: Straight legs (gastro) / Knees slightly bent (soleus) / Single-leg
C. Light calf plyometrics
Why: Plyometrics (jumps, jump rope) are essential for increasing tendon stiffness and preparing the Achilles tendon for repeated running impacts. They also improve neuromuscular coordination.
Exercise examples:
- Jump rope: 2-3 sets of 30-60 seconds
- Hops in place: 3 sets of 10-15 short, fast jumps
- Explosive calf raises: 3 sets of 10 reps
⚠️ Progression: Start with eccentric work for 4-6 weeks before adding plyometrics.
3. Shin splints: protect your tibias
What is it?
Pain along the inner edge of the tibia (front leg bone), often diffuse. Typical in beginner runners or after a sudden increase in volume.
Causes
- Overload of the tibialis posterior (foot stabilizing muscle)
- Weakness of foot and ankle muscles
- Worn-out or unsuitable shoes
- Hard surfaces (asphalt) without gradual adaptation
Prevention exercises
Strengthening foot muscles
A. Barefoot walking
10-15 minutes per day on a stable surface (grass, mat) to wake up the intrinsic foot muscles.
B. Short Foot Exercise
Contract the foot arch by "shortening" the foot (without curling the toes). Hold 5-10 sec, repeat 15 times.
C. Toe raises
Standing, lift only the toes while keeping heels on the ground. 15-20 reps, 3 sets.
4. IT band syndrome
What is it?
Pain on the outside of the knee, caused by friction of the iliotibial band over the femoral condyle. Typical in trail runners (descents) and long-distance runners.
Causes
- Weak gluteus medius → Pelvis dropping laterally
- Tight iliotibial band
- Sudden increase in elevation loss (repeated descents)
Prevention exercises
Side plank + hip abduction
Side plank with top-leg lift. 10-12 reps/side, 3 sets.
Monster walk (with band)
Band around the ankles, lateral walking in a semi-squat position. 10-15 steps/side, 3 sets.
IT band/TFL stretch
Cross the leg to stretch behind the other, push the hip sideways. Hold 30-45 sec, 2-3 times/side.
Injury prevention program
Weekly routine (20 min, 2x/week)
Session 1: knees and pelvis focus
- • Warm-up: ankle, knee, hip mobility (5 min)
- • Step Down: 3 × 12 reps/leg
- • Wall sit: 3 × 45 sec
- • Clamshells: 3 × 15 reps/side
- • Monster Walk: 3 × 10 steps/side
- • Stretches: quadriceps, glutes, TFL (5 min)
Session 2: calves and feet focus
- • Warm-up: barefoot walking (5 min)
- • Drop Down (eccentric): 3 × 12 reps/leg (straight knee + bent knee)
- • Calf Raises: 3 × 15 reps
- • Short Foot Exercise: 3 × 15 reps
- • Toe Raises: 3 × 15 reps
- • Stretches: calves, plantar arch (5 min)
The golden rules of prevention
- 10% rule: Never increase weekly volume by more than 10% per week.
- Gradual progression: Start far from your goals (70% of your capacity) and progress week by week.
- Listen to your body: Distinguish pain (immediate stop) from soreness (normal). When in doubt, rest 48h.
- Surface variety: Alternate asphalt, trails, grass to reduce repetitive impacts.
- Appropriate shoes: Replace shoes every 600-800 km. Test a new drop progressively.
- Recovery: Rest is part of training. Plan at least 1 day off per week.
- Regular strength training: 2 sessions of 20 min per week are enough to drastically reduce injury risk.
Simple RenfoRun-style version
Separate specific medical protocols from general prevention sessions.
- Session 1 — knees/pelvis: 3 rounds of controlled squat, side plank with abduction, glute bridge.
- Session 2 — calves/feet: accessory block with eccentric calf raises, foot tapping, short-foot exercise.
The Alfredson protocol remains a specific protocol, not a classic RenfoRun session.
You understand the method. RenfoRun gives you the workout.
No planning, no hesitation — just open the app and follow the session.
- ✓ Guided workouts with timer — just follow along
- ✓ Automatic progressions: your sessions evolve every week
- ✓ 12 to 25-minute sessions, designed to fit your running schedule
- ✓ Built exclusively for runners — road or trail
Conclusion
Running injuries are not inevitable. With targeted strength work, appropriate progression, and attentive listening to your body, you can considerably reduce the risks.
Remember: investing 20 minutes per week in prevention saves weeks (or even months) of forced time off.
Take care of your knees, tendons, and feet. They will carry you far! 🏃💚