On Cloud X 3 review: The biomechanics of a true hybrid training shoe

The Cloud X 3 functions as a true hybrid only for moderate lifting and short runs (about 1 to 4 miles) by pairing firmer, less-compressible CloudTec foam with a Speedboard to improve force transfer while still attenuating running impacts that can exceed 2.5 times body weight. This evidence-based review breaks down where that stability and cushioning compromise works, where it doesn’t, and what your joints are most likely to notice.

The relationship

Concurrent training combines lifting and running in the same program, and it creates competing footwear demands: a stable base for lifting and compliant cushioning for running. While this approach is highly effective for general fitness and metabolic health, it presents a unique challenge for the musculoskeletal system, especially the feet. The biomechanical requirements of lifting weights are diametrically opposed to those of running.

When an athlete performs a squat or a deadlift, the primary need is a stable surface area that minimizes center-of-pressure excursions (swaying) to reduce unnecessary joint torque. According to a 2012 study in the Journal of Strength and Conditioning Research, lifters showed measurable kinematic changes during the back squat when they wore weightlifting shoes, highlighting how footwear can alter squat mechanics and stability demands.^[1] Conversely, during the stance phase of running, the foot must absorb vertical ground reaction forces that can exceed 2.5 times body weight. Research published in Acta Physiologica Scandinavica in 1989 measured walking and running at different speeds and found that ground reaction forces increase as speed rises.^[2] Traditionally, this required two different pairs of shoes: a flat, hard sole for lifting and a soft, high-drop foam sole for running. The On Cloud X 3 enters the market as a “quiver killer,” designed to mediate these opposing forces.

Data suggests that using unstable, highly cushioned running shoes during heavy loading can increase instability at the ankle joint, potentially compromising force output and increasing injury risk. Alternatively, running in rigid lifting shoes lacks the necessary shock attenuation, increasing the transmission of impact shock to the tibial bone and knee joint. The relationship between the Cloud X 3 and the athlete is one of compromise: it provides a stable enough platform for moderate lifting (squats, box jumps) while retaining the mechanical characteristics needed for short-distance displacement (running 1 to 4 miles).

How it works

The biomechanical function of the Cloud X 3 relies on three specific engineering elements: the CloudTec sole, the Speedboard, and the upper construction. Understanding these helps explain why the shoe functions differently than a standard maximalist running shoe.

CloudTec and impact forces

The proprietary “CloudTec” cushioning system consists of hollow open tubes of rubber and foam on the outsole. Upon impact, these elements compress to absorb vertical shock and then firm up to provide a solid base for the push-off phase. In clinical terms, this variable density attempts to alter the rate of loading, which is how quickly force is applied to the foot.

For the runner, reducing rapid loading may matter because, as reported in biomechanical research, higher impact loading patterns have been associated with tibial stress injury risk in runners.^[3] However, because the Cloud X 3 is designed for versatility, the foam is denser than in distance-specific models. This density may help limit the “marshmallow effect” during lifting. Soft foam can feel unstable under heavier loads and may worsen knee tracking in some lifters.

The Speedboard and energy return

Embedded within the midsole is a semi-rigid plate known as the Speedboard. A 2000 study in Medicine & Science in Sports & Exercise reported that changing midsole bending stiffness influenced lower-limb joint energetics and performance measures such as jump height, which is part of why plated and stiffer shoes can feel more “snappy.”^[4]

In the context of the Cloud X 3, the Speedboard serves a dual purpose. During dynamic movements like box jumps or burpees, it loads with potential energy and releases it, aiding in explosive power. During static lifts, it provides torsional rigidity, helping prevent the foot from twisting mid-lift. This can reduce unwanted strain during lateral movements by limiting excessive midfoot motion.

Proprioception and stack height

Proprioception is the body’s ability to sense its position in space. High-stack shoes (thick soles) can blunt the sensory feedback from the mechanoreceptors on the sole of the foot. The Cloud X 3 maintains a relatively low profile compared to maximalist runners. According to research on men and athletic footwear, enhanced plantar sensation has been linked to better balance control and reduced risk of ankle inversion injuries.^[5]

For athletes performing functional fitness, this ground feel is essential. When you can feel the floor, you can better engage the intrinsic foot muscles to stabilize the arch. However, users should note the minimal arch support inherent in the design, which places greater demand on the posterior tibialis tendon to maintain arch height.

Conditions linked to it

Choosing the correct footwear is a preventive measure against several lower-extremity pathologies. The Cloud X 3 is positioned to mitigate specific risks associated with cross-training, though its design introduces limitations for certain populations.

Tibial Stress Syndrome (Shin Splints): This condition involves inflammation of the muscles, tendons, and bone tissue around the tibia. It is often caused by repetitive loading without adequate shock absorption. While the Cloud X 3 provides adequate cushioning for short runs (1 to 4 miles), runners with higher body mass or those running longer distances may require more cushioning, different geometry, or a different training progression to reduce tibial stress.

Plantar Fasciopathy: Plantar fasciopathy is an overuse injury of the plantar fascia that causes heel or arch pain and may involve tissue degeneration, with inflammation sometimes present early. The Cloud X 3 has been noted for its lack of aggressive arch support. For athletes with flexible flat feet (pes planus), the lack of structural support during heavy loading or high-repetition bounding can exacerbate plantar fascia strain. Conversely, for those with strong intrinsic foot muscles, the neutral bed allows natural foot function without artificial propping.

Patellofemoral Pain Syndrome (Runner’s Knee): Instability at the foot often translates up the kinetic chain to the knee. A more stable platform may feel better for some men with knee symptoms, but direct evidence that the Cloud X 3 reduces tibial rotation or patellofemoral pain is lacking. Case-control research on patellofemoral pain syndrome does suggest that foot and ankle characteristics can differ in people with this condition.^[6]

Symptoms and signals

Determining if a hybrid shoe like the Cloud X 3 is working for your specific biomechanics requires monitoring for subtle physiological signals. Pain is a lagging indicator. Pay attention to these early warning signs during or after training.

• Medial shin pain: Tenderness along the inner shin bone after a run suggests the cushioning, training load, or mechanics may not be a match for your running volume.
• Heel slippage: If the heel slides up and down during lunges or sled pushes, the heel counter may not be locking the calcaneus (heel bone) effectively, reducing power transfer.
• Lateral foot cramping: Cramping on the outside of the foot often indicates the shoe is too narrow, compressing the metatarsals.
• Knee wobble (Valgus): If your knees cave inward during squats, the shoe’s foam may be compressing under your load or the lateral support may be insufficient for your anatomy and technique.
• Hot spots: Localized redness or blistering on the toes or ball of the foot indicates friction, possibly due to the upper mesh not containing the foot securely during lateral cuts.

What to do about it

If you are considering the Cloud X 3 as your primary training shoe, follow this evidence-based protocol to ensure it matches your physiological needs and training intensity.

1. Perform the “Wet Test” or Single-Leg Stance Test
   
   Use these only as rough observations, not as a diagnosis or a direct guide to insoles. Wet your foot and step on a piece of cardboard, or stand on one leg barefoot, to get a general sense of your arch shape and balance control. Then trial the Cloud X 3 during walking, easy gym work, or other light loads first. If pain, recurrent shin symptoms, or instability develops, seek evaluation from a podiatrist, physical therapist, or sports medicine clinician.
2. Implement a graded transition protocol
   
   Do not immediately run your maximum distance in these shoes if you are coming from a maximalist (highly cushioned) shoe. The lower drop and firmer ride can increase the load on the Achilles tendon and calf musculature. According to a 2018 Scientific Reports study, highly cushioned shoes were associated with increased leg stiffness and higher impact loading in tested runners, which may offset some cushioning benefits for certain people.^[7] Start with walking and gym sessions, then introduce running in 0.5-mile increments to allow your tissues to adapt.
3. Limit usage by activity type
   
   Restrict the Cloud X 3 to its intended “sweet spot”: mixed-modal workouts (HIIT), lifting sessions involving moderate loads, and runs under 4 miles. Use it for weights where the foam does not noticeably compress or destabilize you. If the shoe compresses, your foot wobbles, or knee tracking degrades, switch to a dedicated lifting shoe. For marathon training or maximal lifting (1 to 3 rep max effort), choose specialist footwear to better match the task.

Myth vs fact

Myth: More cushioning is always better for your joints.

Fact: It depends. In some runners and conditions, very soft or highly cushioned shoes can be associated with higher leg stiffness and higher impact loading, as reported in a 2018 Scientific Reports study. That pattern may reduce the expected benefit of extra cushioning for certain people, especially if the shoe feels unstable to them.^[7]

Myth: You can use running shoes for heavy deadlifts.

Fact: Compressible running soles can absorb the force you generate and reduce stability, which can degrade technique and increase unwanted motion at the ankle, knee, or low back under heavier loads.

Myth: The Cloud X 3 prevents all impact injuries.

Fact: No shoe prevents injury on its own. Load management (how much you train) and biomechanics (how you move) are primary drivers of injury risk. Shoes are tools that can help or hinder depending on the task and the person.

Bottom line

Yes, the Cloud X 3 can be a true hybrid shoe for men who lift moderate loads and run short distances (about 1 to 4 miles) in the same training week. It is not ideal for long-distance run training or maximal strength work because the cushioning can still compress under heavy loads and the platform is not as rigid as a dedicated lifting shoe. If you want one pair for mixed-modal workouts, short runs, and general gym training, it fits the job.

References

1. Sato K, Fortenbaugh D, Hydock DS. Kinematic changes using weightlifting shoes on barbell back squat. Journal of Strength and Conditioning Research. 2012;26:28-33. PMID: 22201687
2. Nilsson J, Thorstensson A. Ground reaction forces at different speeds of human walking and running. Acta Physiologica Scandinavica. 1989;136:217-27. PMID: 2782094
3. Milner CE, Ferber R, Pollard CD, et al. Biomechanical factors associated with tibial stress fracture in runners. Medicine and Science in Sports and Exercise. 2006;38:323-8. PMID: 16531902
4. Stefanyshyn DJ, Nigg BM. Influence of midsole bending stiffness on joint energy and jump height performance. Medicine and Science in Sports and Exercise. 2000;32:471-6. PMID: 10694134
5. Robbins S, Waked E, Gouw GJ, et al. Athletic footwear affects balance in men. British Journal of Sports Medicine. 1994;28:117-22. PMID: 7921911
6. Barton CJ, Bonanno D, Levinger P, et al. Foot and ankle characteristics in patellofemoral pain syndrome: a case control and reliability study. The Journal of Orthopaedic and Sports Physical Therapy. 2010;40:286-96. PMID: 20436240
7. Kulmala JP, Kosonen J, Nurminen J, et al. Running in highly cushioned shoes increases leg stiffness and amplifies impact loading. Scientific Reports. 2018;8:17496. PMID: 30504822