Sandbag lunges and loaded carries: the leg-killer stations
Sandbag lunges and loaded carries in hybrid races: rack position, bracing, step length, breathing under load and how to train the leg-killer stations.
Dr. Pablo Lozano Lominchar
9 min read
> The information in this article is based on published scientific literature and is for educational purposes only. It does not constitute medical or training advice. Any training programme should be designed and supervised by a qualified coach, with medical clearance from a healthcare professional.
Sandbag lunges and loaded carries are the two stations that most reliably destroy the runs that follow them, typically involving 100 m of walking lunges under a 10–30 kg bag and 200 m of farmers carry with 16–32 kg per hand. A 100 m lunge lane is roughly 90–130 steps depending on your height, each one a single-leg eccentric-to-concentric effort under load — the equivalent of a high-rep unilateral leg workout dropped into the middle of a 60–90 minute race. Athletes lose more time in the 400–800 m after these stations than in the stations themselves. This article covers rack position, bracing, step length, breathing, why the following run collapses, and how to train all of it.
Why the lunge station wrecks the next kilometre
A 100 m sandbag lunge lane produces 45–65 repetitions per leg under load, generating high eccentric stress in the quadriceps and gluteals plus a sustained isometric demand on the trunk and upper back. Three things happen simultaneously. [1][2]
First, the quadriceps accumulate eccentric work at each descent, which is the most mechanically damaging contraction type and the one that most degrades subsequent force production. Second, holding a bag across the upper back or in a front-rack position restricts rib expansion, so ventilation becomes shallow and rapid exactly when oxygen demand is high. Third, the hip flexors are loaded through a large range while the trunk resists flexion, which is precisely the pattern you then need intact for running mechanics.
The result is a run in which stride length shortens, cadence rises, and pace is 20–60 seconds per kilometre slower than fresh pace for the first 300–500 m. That is normal. The trainable question is how quickly you recover the mechanics, not whether you lose them. This is the same physiology discussed in running on tired legs.
Rack position: three options and when to use each
The rack position determines how much of the load your trunk has to fight, and the three standard options — back rack, front rack and bear hug — differ by roughly 10–20% in perceived difficulty for the same weight.
- Back rack (bag across the upper trapezius and rear delts). The most efficient for a long lane. The load sits close to the spine's line of action, the arms fatigue least, and breathing is least restricted. The cost is that it demands good thoracic control — if the bag slides, you are constantly rescuing it. Hold the bag by the handles or by hugging the ends forward over the shoulders.
- Front rack (bag across the collarbones and front delts). More upright torso, quadriceps-dominant, but breathing is noticeably compromised because the bag presses on the upper chest. Reasonable for short distances or for athletes with limited shoulder mobility.
- Bear hug (bag hugged against the chest). Highest trunk and grip cost, worst for breathing. Use it only as a temporary rescue position when the bag slips.
Bracing and step length: the two variables you can control
Under a loaded lunge, an effective brace means 360-degree intra-abdominal pressure at roughly 50–70% of a maximal brace, held continuously rather than re-created each rep. A maximal brace cannot be sustained for 60 repetitions, and no brace at all lets the lumbar spine extend under load. [3]
Practical cues that work:
Step length is the most under-considered variable. A shorter step, roughly 60–75% of your natural walking stride, reduces the range of motion, shortens the eccentric phase and lets you turn the lane over faster. Long, deep lunges look impressive and cost you both time and quadriceps. Whether your trailing knee must touch the ground depends on the event's standards — if it does, aim for a light touch, not a drop.
Turnaround discipline. Most lanes require one or more turns. Practise turning without unracking the bag: short steps, pivot on the outside foot, keep the trunk tall. Athletes routinely lose 5–10 seconds and a rescued bag on each turn.
Breathing under load
Under a racked load, most athletes default to shallow apical breathing at 40–55 breaths per minute, which is both inefficient and a fast route to lightheadedness. The alternative is a fixed breathing rhythm tied to the steps.
A pattern that works for most: inhale over one step, exhale over the next, or for heavier bags, inhale on the down phase, short exhale through pursed lips on the drive up. The key is that the exhale must be against slight resistance so intra-abdominal pressure is not lost entirely. Never hold your breath for more than two or three consecutive reps — a prolonged Valsalva across a 100 m lane produces exactly the dizziness and blurred vision that ends people's races.
Farmers carry and other loaded carries
A 200 m farmers carry with 2 × 16–32 kg is primarily a grip, trunk and gait-stability challenge, and the limiting factor is almost always the forearms rather than the legs. Grip failure ends the carry long before the legs do. [3][4]
The technique points that matter most:
- Stand tall, shoulders packed down and back. Shrugging the load is fatiguing; letting the shoulders sag stretches the upper trapezius under load.
- Short, quick steps at 130–150 steps per minute. Long strides cause swing, swing causes lateral trunk work, lateral trunk work costs energy.
- Hook grip on the handles where possible, and grip at 70–80% rather than maximally. Consciously relaxing the grip by 20% adds 20–40 m of carry distance for most athletes.
- Plan your drops. If you cannot do 200 m unbroken, two planned 10-second drops at 70 m and 140 m are far faster than one panic drop at 90 m followed by three more.
- Set the implements down under control. Dropping from height risks equipment penalties in some events and always risks your own toes.
How to train lunges and carries
Two dedicated sessions per week, each containing 300–600 m of total lunge distance or 600–1,000 m of total carry distance, covers the specific demand for most athletes. Build the capacity in three layers. [5]
Layer 1 — strength. Heavy split squats, rear-foot-elevated split squats and heavy deadlifts at 3–5 sets of 4–6 repetitions build the force reserve that makes a 20 kg bag feel light. Heavy resistance training at high relative loads improves running economy and neuromuscular qualities in distance runners without adding mass when volume is controlled (Blagrove 2018), and the improvements track with strength and power gains rather than hypertrophy (Balsalobre-Fernández 2016).
Layer 2 — specific endurance. Weekly work at or near race load: 4 × 50 m sandbag lunge with 90 seconds rest, or 5 × 100 m farmers carry with 60 seconds rest. Record the load, distance and rest so you can progress one variable at a time.
Layer 3 — transitions. The session that changes race outcomes: 3–4 rounds of 50 m lunge + 400 m run, or 100 m carry + 400 m run, at race effort. Pair it with the sled work described in sled push technique, since both stations feed the same problem.
Progress load and distance conservatively. Weekly increases above roughly 30% in running volume have been associated with higher injury risk (Nielsen 2013), and keeping acute training load within approximately 0.8–1.3 times the chronic load is a reasonable heuristic for avoiding spikes (Bowen 2017). Lunges and carries are heavy, eccentric, and easy to overdo the week after a good session.
Finally, remember that the ability to hold pace late in a race depends on durability — the resistance of your physiological profile to deterioration after prolonged prior work — and that this quality is trained specifically, by doing hard work when already fatigued (Jones 2024; Zanini 2025).
Frequently asked questions
What weight should I train the sandbag lunge with?
Train at race load and slightly above. If your event uses 20 kg, do most specific work at 20 kg and a smaller amount at 25 kg over shorter distances. Training far above race load for long lanes tends to break technique and adds eccentric damage without improving race performance.
Back rack or front rack for sandbag lunges?
Back rack for almost everyone over 100 m: it restricts breathing least and fatigues the arms least. Use the front rack only if shoulder or thoracic mobility prevents a stable back rack, and accept that it will cost you more ventilatory freedom.
How do I stop my grip failing on the farmers carry?
Grip at 70–80% rather than maximally, use a hook grip if the handles allow it, keep the shoulders packed and take planned 10-second drops rather than emergency ones. Add two sets of 45–60 second heavy holds twice a week; grip endurance responds quickly, usually within 3–4 weeks.
Why do I run so badly after the lunges?
Because 45–65 loaded repetitions per leg produce substantial eccentric quadriceps fatigue and restricted breathing, so stride length shortens and cadence rises. Expect 20–60 seconds per kilometre slower for the first 300–500 m, and train the transition directly so you recover mechanics faster.
Putting it together
Sandbag lunges and loaded carries are not tests of toughness — they are technical stations with a large downstream cost. Rack the bag on your back, brace at two-thirds and hold it, shorten your steps, breathe on a fixed rhythm, grip at 80% and plan your drops. Then train the run that follows, not just the station.
If you want a 12-week concurrent plan that builds the strength layer, the specific endurance layer and the transition layer in the right order, the plan generator at hybridbeastbrain.com is completely free — build your plan here. The programming rationale is on the science page, and upcoming events are listed on the races page. If you are new to the format, start with what is a hybrid fitness race.
References
The claims above are sourced to the papers below, numbered in the order they appear in the text. Where a number sits at the end of a paragraph, it points to the work that claim rests on.
Dr. Pablo Lozano Lominchar, MD, PhD, EBPSM
Surgical Oncologist · Hospital General Universitario Gregorio Marañón, Madrid
Specialist in peritoneal malignancies, sarcomas, and complex pelvic surgery. Associate Professor of Surgery at Complutense University of Madrid. Hybrid athlete and creator of the HybridBeastBrain training engine.
ORCID: 0000-0002-5413-8449
How this article was made: it is a summary of the available scientific literature, not original research. The search and the summarising were done with AI assistance, and the accuracy was then checked by hand against the sources cited. If you spot an error, write to us and we will correct it.