Why My Hip Flexors Nearly Broke Me on the Fan Dance — And the Training Plan I'm Using to Fix It

I've done some tough things. But nothing quite prepared me for the moment, somewhere on the descent from Pen y Fan, when my hip flexors screamed at me to stop.

We'd recently completed the SAS Fan Dance, 24 kilometres through the Brecon Beacons, carrying a 20kg rucking backpack, navigating one of the most unforgiving landscapes in the UK. It was one of the proudest moments of my life. But it also exposed a weakness I hadn't trained for specifically: the relentless, grinding demand that loaded marching puts on your hip flexors.

If you haven't done the Fan Dance, or a long ruck like it, let me paint you a picture. You're not just walking. You're lifting your legs, step after step, hour after hour, against the resistance of a weighted pack that's constantly driving you into the ground. Every stride requires your hip flexors to fire and pull that leg forward. Now multiply that by thousands of steps, add steep gradients, uneven terrain, and a 20kg rucking backpack, and you start to understand the problem.

By the halfway point, I could feel a tightness building at the front of my hips. By the final climb back up Pen y Fan, it had turned into a burning ache that radiated down into my quads and up into my lower back. I finished. But I finished hurting in a way I hadn't anticipated, and hadn't trained for.

Why Rucking Is So Hard on Your Hip Flexors

Here's what I've learned since the Fan Dance: the hip flexors are arguably the most overlooked muscle group in rucking preparation.

Most people, myself included, focus on building leg strength (squats, lunges, step-ups) and back resilience for carrying a rucking backpack or weighted vest. Those things matter. But the hip flexors, primarily the iliopsoas and rectus femoris, are the engine of every single step you take when marching under load.

When you're carrying a heavy weighted vest or rucking backpack, your body has to work harder to maintain posture and drive each leg forward. The hip flexors fatigue because:

• They're working concentrically and eccentrically on every stride, contracting to lift the leg, then resisting on the way down.

• A heavy pack compresses your posture, which shortens the hip flexors and puts them in a chronically shortened, stressed position for hours at a time.

• Uneven terrain forces micro-adjustments on every step, creating asymmetric loading that accelerates fatigue in ways flat running never does.

The result? By mile 10 of a loaded march, many people, including me on the Fan Dance, are compensating with their lower back and quads, which only makes things worse.

The Hip Flexor Strengthening Plan I Wish I'd Had Before the Fan Dance

Since finishing the Fan Dance, I've been working with a structured plan to build hip flexor strength and endurance specifically for rucking. If you're training for a challenge, whether it's the Fan Dance, a HIKE event, a military fitness test, or just getting more comfortable under a weighted vest, this is the plan I'd recommend.

It's built around three principles:

1. Strengthen the hip flexors under load

2. Lengthen and restore range of motion

Integrate them into full rucking movement patterns

Phase 1: Weeks 1–2 — Foundation and Mobility

Before you load the hip flexors, you need to restore their range of motion. After years of sitting — and post-Fan Dance tightness — mine were chronically shortened. Start here.

Daily Mobility Work (10 minutes every morning)

• Low Lunge Hip Flexor Stretch — 3 x 60 seconds each side. Drop into a deep lunge, tuck your pelvis under, and push your hips forward. You should feel a deep pull through the front of the trailing hip. This is the foundation of everything.

• Couch Stretch — 2 x 60 seconds each side. Kneel with your rear foot elevated on a bench or sofa, drive your hips forward. Brutal. Effective.

• 90/90 Hip Rotation Stretch — 2 x 45 seconds each side. Improves internal and external rotation, which supports the hip flexors during multi-directional movement on uneven terrain.

Strength Work (3x per week, e.g. Mon/Wed/Fri)

• Lying Leg Raises — 3 x 15. Flat on your back, legs straight, raise to 90° and lower slowly. This isolates the hip flexors without loading the spine. Focus on controlled lowering, that eccentric phase is where strength is built.

• Standing Knee Raises (slow tempo) — 3 x 12 each side. Stand tall, drive one knee up to hip height, hold for 2 seconds, lower slowly over 3 seconds. The slow tempo is key. This mimics the demand of rucking step by step.

Dead Bug — 3 x 10 each side. Core and hip flexor coordination. Lying on your back, arms and legs extended to ceiling, lower opposite arm and leg simultaneously while keeping your lower back flat. Essential for posture under a rucking backpack.

Phase 2: Weeks 3–4 — Loading and Endurance

Now we start adding load and volume. This is where the real rucking-specific adaptation happens.

Loaded Hip Flexor Work

• Banded Standing Knee Drives — 3 x 15 each side. Attach a resistance band low to a rack or door, loop around your knee, and drive it up against the resistance. This directly simulates the demand of lifting your leg against a heavy weighted vest or rucking backpack. Start with a light band and progress.

• Step-Ups with High Knee Drive — 4 x 10 each side. Use a 40–50cm box. Step up and drive the trailing knee to hip height at the top. Add a light weighted vest in week 4 if you have one — even 5–10kg changes the stimulus dramatically.

• Weighted Leg Raises — 3 x 12. As above, but hold a light dumbbell between your feet. Progress the weight week over week.

• Incline Reverse Crunches — 3 x 12. On a decline bench, use your hip flexors to drive your knees up towards your chest. One of the best exercises for building hip flexor endurance that's often ignored.

Endurance Circuit (once per week)

This is the one that makes the difference for long-duration rucking. Set a timer for 20 minutes and cycle through:

1. Standing knee raises — 20 reps each side

2. Banded knee drives — 15 each side

3. Low lunge hold — 30 seconds each side

4. Dead bug — 10 each side

Minimal rest. The goal is to build the specific muscular endurance your hip flexors need to last for hours under a rucking backpack.

Phase 3: Weeks 5–8 — Rucking Integration

Now we take the strength work and integrate it into actual rucking. This is where the training becomes specific.

Weighted Carries and Step Work

• Loaded Step-Ups — 4 x 12 each side, wearing your weighted vest or rucking backpack. Use 20–30% of your target ruck weight initially, building to full weight by week 8.

• Uphill Walks with Load — 2–3 x 20 minutes per week. Find a hill or use a treadmill at 8–12% incline. Wear your rucking backpack. This is the most specific adaptation you can make for events like the Fan Dance. Focus on posture — tall spine, engaged core, deliberate knee drive.

• Farmer's Carries — 3 x 40 metres. Heavy dumbbells or kettlebells, one in each hand. Builds total-body postural endurance under load, which reduces the compensatory strain on your hip flexors during long rucks.

Ruck Practice (progressive)

• Week 5: 8km ruck with 25% of target weight, flat terrain

• Week 6: 10km ruck with 50% of target weight, mixed terrain

• Week 7: 12km ruck with 75% of target weight, hilly terrain

• Week 8: 15km ruck with full target weight — this is your test event

After every ruck, spend 10–15 minutes on the mobility work from Phase 1. Non-negotiable

What I'd Do Differently Before the Fan Dance

Looking back, my rucking training was almost entirely focused on building general fitness, running, squats, weighted carries. All of it had value. But none of it specifically prepared my hip flexors for the sustained, step-by-step demand of carrying a 20kg rucking backpack for 24 kilometres over mountain terrain.

If I were preparing for the Fan Dance again, I'd:

1. Start hip flexor-specific training 8–10 weeks out, not just general leg work

2. Do weekly hill rucks from week 4, wearing my rucking backpack at progressive weights

3. Prioritise the daily mobility routine — 10 minutes every morning is not a luxury, it's essential maintenance

4. Use a weighted vest for gym sessions in the final 4 weeks to simulate the postural demand of rucking on squats, step-ups, and carries

The Fan Dance was a phenomenal experience, one I'd recommend to anyone looking to test themselves physically and mentally. But I'll be going back better prepared. And when I do, my hip flexors won't be the thing that nearly stops me.

Kit We Used

For the Fan Dance, I carried a rucking backpack loaded to 20kg. Getting your pack fit right is as important as the training itself, an ill-fitting rucking backpack will transfer load incorrectly onto your hips and spine, accelerating fatigue and increasing injury risk. We'll be covering pack selection and fit in a future post.

If you're looking to add load to gym training in the build-up to a ruck event, a good weighted vest is one of the most versatile tools you can own, it allows you to overload step-ups, carries, and loaded walks without committing to a full pack.

Check out the Force Fit range for weighted vests and rucking backpacks built for exactly this kind of training.