The Hamstring
If there's one thing I know, it's never to mess with Mother Nature, Mother-In-Laws, and your Mother Freakin' Hamstring.
The hamstring is a crucial muscle group because it plays a vital role in everyday movements like walking, running, bending the knee, and extending the hip, stabilizes the knee and hip joints, and helps to maintain proper posture by supporting the pelvis and spine.
Hamstring Prehab / Rehab
The best way to rehab the hamstring is through eccentric exercise (just like for the calves). This works great for low grade tendinopathy and very mild partial tears. Eccentric exercises are scientifically proven to promote tendon healing, improve tendon strength, and prevent re-injury. Eccentric exercises involve lengthening the muscle-tendon unit while it is under tension, as opposed to a concentric contraction (which is what mostly do when lifting weights) where the muscle shortens. 

This method is best used in prehab / rehab for hamstring tendinopathy, hamstring strains, and post-injury strengthening. It helps realign collagen fibers, promote healing, and increase tendon stiffness to reduce the risk of re-injury. 
What Exercises Should I do?
  • Early-Stage Rehab: Begin with light, controlled eccentric exercises like the hamstring bridge and Isometric Hold.
  • Mid-Stage Rehab: Progress to single-leg Romanian deadlifts and step-downs.
  • Late-Stage Rehab: Progress to Nordic Hamstring Curls, which require the most strength and control.  
  • Prehab / Maintenance: Romanian deadlifts, Nordic Curls, Step-Downs. 
Exercises:
Eccentric Bridge (Supine Hamstring Curl): Easy
  • Lie on your back with you feet on a slider, towel, or balance ball.
  • Lift your hips so your body forms a straight line from shoulders to knees.
  • Slowly slide your feet away from your body, straightening your legs.
  • Once fully extended, lower your legs to the ground and reset.
  • Repeat for 3 sets of 8-12 reps. 
Hamstring Isometric Hold: Easy
  • Lie on your back with your feet on the ground or on a bench (a little more challenging)
  • Lift your hips so your body forms a straight line from shoulders to knees.
  • Hold the position for 10-15 seconds.
  • Slowly lower your hips to the ground over 3-4 seconds.
  • Repeat for 3 sets of 8-12 reps. 
Single Leg Romanian Deadlift: Medium
  • Stand on one leg while holding a dumbbell, kettlebell, or a small child.
  • Slowly hinge forward at the hips while keeping a slight bend in your knee.
  • Lower your torso toward the ground, keeping the back straight, while the other leg extends behind you.
  • Lower the weight toward the floor.
  • Return to the starting position with good form and control
  • Repeat for 3 sets of 10-12 reps per leg
Eccentric Step Down: Medium
  • Stand on a platform or low box on one leg.
  • Slowly lower your opposite leg toward the ground in a controlled manner.
  • As your opposite foot touches the ground, engage your hamstring to return to the starting position.
  • Repeat for 3 sets of 10-12 reps per leg
Nordic Hamstring Curl: Hard
  • Kneel on a soft surface, like a mat with your feet anchored under a partner's hands, or padded weighted bar.
  • Slowly lean forward from the knees, keeping your hips and spine in a straight line.
  • Lower your body slowly to the ground in a controlled manner.
  • Catch yourself with your hands just before you hit the ground.
  • Slide back to return to the starting position.
  • ​Repeat for 3 sets of 8-12 reps. 
How Often Should you Train Eccentric Hamstring Exercises?
  • Frequency: 2-3 times per week
  • Sets and Reps: 3 sets of 8-12 reps per exercises
  • Rest: Allow 48 hours of recovery between sessions if soreness persists.
Precautions for Eccentric Hamstring Exercises:
  • Avoid Pain: Mild discomfort is okay, but sharp or severe pain is a sign of pushing too hard.
  • ​Go Slow: The eccentric phase should be slow, about 3-4 seconds for maximum tendon benefit.
  • Progress Gradually: Start with isometric exercises and progress to Nordic Curls only when ready.
  • Avoid Fatigue: When the hamstrings are too fatigued, they cannon control the load properly, which can increase injury risk. 
  • Doctor Time: If pain persists for 2-3 weeks or there is sharp pain or popping, there is weakness or loss of strength, then see a physician.