The Best Balance Boards for Core Training in 2026#

Key Takeaway

The Indo Board Original Training Package is our top pick for core training. Its classic roller-and-deck design has been trusted by surfers, snowboarders, and physical therapists for over 30 years, delivering exceptional proprioceptive challenge and genuine full-body core engagement at a mid-range price of $130–$160.

Balance boards have evolved from niche rehabilitation tools into mainstream fitness equipment, and for good reason. Research consistently demonstrates that balance training activates deep stabilizing muscles of the lumbar spine, hips, and ankles that traditional strength training largely ignores ^[1]. Whether you are a surfer looking to sharpen your proprioception, an office worker who wants passive core engagement at a standing desk, a physical therapy patient rebuilding ankle stability, or a senior focused on fall prevention, there is a purpose-built balance board for your needs. The challenge is cutting through the noise of dozens of products to find the one that actually delivers results.

For this guide, we evaluated five of the most highly regarded balance boards across multiple criteria: board type and mechanism, difficulty progression, weight capacity, deck dimensions, surface grip quality, and overall value. We cross-referenced clinical rehabilitation literature ^[2], long-form expert reviews ^[3], and ergonomics research ^[4] to provide recommendations you can trust. Each product below represents the best in its class. Use the comparison table to quickly identify which board suits your goals, then dive into our detailed reviews for the full picture.

Best Balance Boards for Core Training - Quick Comparison 2026

Product	Type	Best For	Weight Cap.	Difficulty	Price Range
Indo Board Original Training Package	Roller & Deck	Athletes & PT	250 lbs	Intermediate–Advanced	$130–$160
Revbalance 101 v2	360° Spring-Loaded	Progressive Training	300 lbs	Beginner–Advanced	$200–$260
StrongTek Professional Wooden Balance Board	Rocker/Wobble	Standing Desk Users	350 lbs	Beginner–Intermediate	$170–$200
Yes4All Wooden Wobble Balance Board	Wobble	Beginners & Rehab	300 lbs	Beginner	$25–$40
BOSU 26 Inch Pro Balance Trainer	Dual-Sided Dome	Versatile Training	300 lbs	Beginner–Advanced	$150–$175

Prices and availability last verified: April 3, 2026

Best Overall

Indo Board Original Training Package#

Best for: Athletes, surfers, snowboarders, skateboarders, and experienced gym-goers seeking maximum proprioceptive challenge and deep core muscle activation

🥇Editor's ChoiceAthletes, surfers, snowboarders, skateboarders, and experienced gym-goers seeking maximum proprioceptive challenge and deep core muscle activation

The Original Indo Board Training Package - Balance Board Trainer for Core Strength, Stability & Athletic Performance - Surfing, Skateboarding, Snowboarding, Yoga, Physical Therapy & More. Includes Board, Cushion and Roller. "Bamboo Beach" Design.

Price not available

BALANCE, STABILITY & FUN: The Indo Board Is designed to improve balance, stability, core strength, coordination, and the agility needed for both sports and everyday life. Engages the whole body to boost posture, awareness, and injury prevention - all while keeping training fun.
USED WORLDWIDE BY ELITE ATHLETES: Originally developed for surf training, the Indo Board has become the go-to balance trainer for functional performance across sports. Endorsed by more national, world, and Olympic champions than all other balance boards combined, It’s trusted by athletes to stay competition-ready.
THE BALANCE BOARD FOR EVERYONE: Designed for all ages and abilities, the Indo Board builds confidence for beginners and helps serious athletes refine their skills.

✓ In Stock

Strengths

+Exceptionally high core activation due to the free-rolling cylindrical urethane roller
+Industrial-grade maple deck withstands heavy daily use for years
+30-inch deck provides ample standing surface for various foot positions
+Time-tested design used in professional surf, skate, and snow training
+Multiple roller diameter options available for further difficulty scaling
+Non-slip grip tape surface prevents dangerous foot slippage during intense sessions

Limitations

−Steep learning curve - genuinely unsuitable for absolute beginners without wall support
−No built-in difficulty adjustment; progression requires purchasing additional rollers separately
−Free-rolling urethane cylinder can scuff hardwood floors without a protective mat underneath
−Higher price than beginner wobble boards at $130–$160
−Minimal lateral containment means the roller can travel off the deck mid-session

Bottom line: If you are serious about balance training and want a board that will challenge you for years, the Indo Board Original is the definitive choice. It is demanding, durable, and trusted by professionals worldwide.

The Indo Board Original Training Package has maintained its status as the benchmark roller-style balance board for a simple reason: it works. The 30-inch maple deck sits atop a cylindrical urethane roller, creating a fundamentally unstable platform that demands continuous neuromuscular corrections from the ankles, knees, hips, and core. Studies on roller-type balance boards confirm this multi-joint activation pattern is significantly more effective at stimulating the deep core stabilizers - particularly the transverse abdominis and multifidus - than static or limited-range wobble boards ^[1]. Indo Board's official product specifications confirm the deck supports up to 250 lbs., with the solid maple construction providing decades of reliable service ^[5].

In practical use, the Indo Board's learning curve is genuine and should not be underestimated. Most new users spend their first week simply learning to stay on the board without gripping a wall, which is itself a highly effective training stimulus for the proprioceptive nervous system. Once you develop baseline competency - typically two to four weeks of consistent 10–15-minute daily sessions - the variety of exercises expands dramatically: single-leg stands, bodyweight squats, shoulder presses, push-up negatives with hands on the deck, and even loaded plank holds. Physical therapists have incorporated Indo Board-style training into ankle rehabilitation protocols, citing improved proprioception scores compared to static balance exercises alone ^[2]. At $130–$160, the Indo Board is a meaningful investment that pays dividends in functional strength and injury resilience for years to come.

Best Premium Pick

Revbalance 101 v2#

Best for: Anyone wanting a single board that grows with their fitness level from total beginner to intermediate athlete; excellent for standing desk use due to its controlled, smooth movement profile

Strengths

+Patented 360° spring-loaded mechanism enables true multi-directional instability training
+Adjustable resistance settings allow genuine difficulty scaling from beginner to advanced
+300-lb weight capacity accommodates a wide range of users safely
+Smooth, controlled spring movement reduces injury risk compared to free-rolling roller boards
+Compact footprint fits easily under a standing desk or in a closet
+Solid construction with quality materials rated for sustained daily use

Limitations

−Premium price of $200–$260 is the highest in this roundup
−Spring mechanism can develop a faint squeak over time without occasional maintenance
−Less dynamic and unpredictable than a free roller for advanced sport-specific training
−Smaller deck surface limits foot placement variety compared to 30-inch boards
−Blue finish can show scuffs and surface wear more visibly than natural wood options

Bottom line: The Revbalance 101 v2 justifies its premium price with unmatched adjustability and a smooth training experience that keeps beginners and advanced users consistently challenged on the same platform.

The Revbalance 101 v2 addresses the most common frustration with balance boards: the chasm between 'too easy' and 'too hard.' Revolution Balance Boards' patented spring mechanism uses a central pivot point surrounded by variable-resistance springs to create smooth, progressive 360-degree instability. At the lowest resistance setting, the board tilts with gentle, predictable movement accessible to seniors and rehabilitation patients. At higher settings, the increased spring tension creates a demand that challenges intermediate athletes. This adjustability makes the Revbalance 101 v2 one of the few boards that can genuinely serve a single user for years without becoming obsolete ^[3].

From a core training perspective, the 360° tilt mechanism is particularly valuable because it prevents the body from establishing a preferred compensation pattern - the tendency to lean in a dominant direction that progressively reduces the training stimulus on weaker stabilizers. By requiring constant multi-directional corrections, the Revbalance 101 v2 ensures the obliques, hip abductors, and rotator muscles of the lumbar spine receive balanced activation every session ^[1]. The board's compact dimensions - approximately 16 inches in diameter - also make it practical for standing desk environments, where its controlled movement profile reduces lower-limb fatigue compared to free-rolling alternatives ^[4]. The $200–$260 price is the highest in our roundup, but for users who want a single progressive tool for long-term training, the investment is well justified.

Best for Standing Desk Users

StrongTek Professional Wooden Balance Board#

Best for: Standing desk workers wanting passive core engagement throughout the workday; beginners and rehab patients who need a stable platform with limited tilt; office environments where natural wood aesthetics matter

Strengths

+Exceptional 350-lb weight capacity - the highest in this entire roundup
+Crossed hardwood base provides stability without sacrificing meaningful core engagement
+Beautiful natural wood aesthetic integrates cleanly with home office environments
+Low profile and lightweight construction for easy placement under a standing desk
+Non-slip top surface and rubber feet protect both user safety and flooring
+Completely silent operation - no rolling or spring noise during work sessions

Limitations

−Limited challenge for experienced balance trainers - primarily a passive engagement tool
−Fixed tilt range cannot be adjusted for progressive difficulty as fitness improves
−Smaller deck size may feel cramped for users with shoe size 12 or above
−Not suitable for dynamic exercises such as jumps, explosive squats, or rapid lateral weight shifts
−Price of $170–$200 is relatively high for the training depth it provides in workout contexts

Bottom line: The StrongTek excels in its niche as a standing desk companion, delivering real ergonomic benefits with a refined design. It is not the right tool for intense workout sessions, but for all-day passive core activation, it is outstanding.

The StrongTek Professional Wooden Balance Board occupies a unique position in this roundup: it is specifically optimized for the standing desk context rather than traditional workout sessions. The crossed hardwood base creates a rocker-style platform with a controlled, limited tilt range that keeps users engaged without demanding the focused attention that a roller or spring-loaded board requires. This design philosophy is directly supported by ergonomics research showing that subtle postural variation - the kind provided by a low-challenge balance board - reduces the musculoskeletal fatigue associated with prolonged static standing ^[4]. StrongTek's 350-lb weight capacity is the highest in this group, making it the most inclusive option for users who require a particularly robust platform.

In terms of core activation, the StrongTek's passive engagement model delivers real cumulative benefits even if individual sessions don't feel intense. A standing desk worker who spends six hours per day on a balance board accumulates far more total core stabilization volume than someone who performs a dedicated 15-minute balance workout and then sits for the remainder of the day ^[4]. The board's natural hardwood construction and clean aesthetic are also genuine advantages in a home office setting where most exercise equipment looks out of place. For dedicated workout use, however, the StrongTek's fixed tilt range and stable base will quickly feel insufficient for anyone with existing fitness experience ^[3]. Think of it as a high-quality ergonomic accessory that moonlights as entry-level fitness equipment - not the other way around.

Best Budget Pick

Yes4All Wooden Wobble Balance Board#

Yes4All Wooden Wobble Balance Board – Exercise Balance Stability Trainer 15.75 inch Diameter - Blue - ²L6CJZ

Best Budget Pick

Price not available

300-POUND STURDY CONSTRUCTION: Solid wooden wobble balance board can support up to 300 pounds and offers a stable platform for your workouts; The 15 3/4 inch broad baps board accommodates both feet
UPGRADED BALANCE CHALLENGE: 15-degree tilt angle and 360-degree rotation of this small balance board allow you to move in any direction; Foot balance board Yes4All improves coordination and adds enjoyment to your fitness routine
STURDY GRIP ANKLE BOARD: Anti-skid pad on the ankle wobble board adult improves grip; Performs side to side, front to back, and circular movement without slipping; Comfortable for both bare feet and shoes

✓ In Stock

The Yes4All Wooden Wobble Balance Board is the gateway drug of balance training - affordable enough to be a low-risk first purchase and effective enough to deliver genuine fitness benefits for beginners and rehabilitation patients. The 15.75-inch circular deck with its hemispherical base creates 360-degree wobble in all directions, activating the ankle stabilizers, peroneal muscles, and lower-limb proprioceptors that form the foundation of all advanced balance work. This type of multi-planar wobble board training has strong clinical support for ankle sprain rehabilitation, with research from the Journal of Athletic Training demonstrating significant improvements in static and dynamic balance scores compared to standard rehabilitation protocols alone ^[2].

At $25–$40, the Yes4All board's price-to-value ratio is genuinely remarkable for a fitness product. The 300-lb weight capacity means it is accessible to most adults, and the non-slip surface coating addresses the safety concern most commonly raised about low-cost balance boards. The primary limitation is its ceiling: a motivated intermediate user will exhaust the training challenge this board provides within four to eight weeks of consistent daily practice ^[7]. At that point, stepping up to the Indo Board Original Training Package or Revbalance 101 v2 will deliver significantly greater returns. For seniors using balance training as fall prevention, however, the Yes4All's limited tilt range is actually an advantage - the controlled movement reduces fall risk during practice itself while still delivering meaningful proprioceptive training benefits ^[8].

Best Dual-Sided Trainer

BOSU 26 Inch Pro Balance Trainer#

Best for: Personal trainers, home gym owners wanting maximum exercise variety, physical therapy patients in supervised settings, athletes using balance training as sports conditioning, and anyone who wants one piece of equipment covering multiple training modalities

Strengths

+Two training surfaces: dome-side up for dynamic balance, flat-side up for advanced unstable platform work
+Commercial-grade construction rated for gym and professional physical therapy environments
+26-inch diameter offers the largest training surface area in this entire roundup
+Adjustable dome inflation allows direct difficulty tuning without accessory purchases
+Enormous ecosystem of BOSU-specific training programs, certifications, and exercise libraries
+Compatible with squats, push-ups, planks, HIIT, and plyometric training - unmatched versatility

Limitations

−Large and heavy at approximately 15 lbs. - by far the least portable option in this comparison
−Dome-up training primarily challenges dynamic balance rather than the deep static core engagement of a roller board
−Flat-side-up training is extremely demanding and completely inappropriate for beginners or rehab patients
−Not suitable for standing desk use due to size, dome height, and instability profile
−Requires dedicated floor space for storage - cannot be easily tucked into a closet

Bottom line: The BOSU Pro is the most complete balance training tool available. If space and budget allow for only one piece of balance equipment in your home gym, the BOSU's unmatched versatility makes it the most defensible long-term choice.

The BOSU 26 Inch Pro Balance Trainer stands apart from every other option in this guide by offering two fundamentally different training experiences in a single product. Used dome-side up - the configuration most users start with - the BOSU creates a soft, yielding surface that challenges dynamic balance during exercises ranging from simple two-legged stands to lateral bounds, single-leg squat holds, and loaded shoulder presses. The inflatable dome can be adjusted by adding or releasing air to modify challenge level directly, making it accessible to beginners while still providing a meaningful stimulus to advanced athletes. BOSU's fitness testing and product data confirm that dome-side squats activate the gluteus medius and hip abductors at significantly higher rates than floor-based squats, contributing to comprehensive lower-body and core conditioning ^[6].

The flat-side-up configuration transforms the BOSU 26 Inch Pro Balance Trainer into an entirely different challenge: a small, elevated, unstable platform requiring exceptional ankle stability, core bracing, and neuromuscular control to stand or perform exercises on. This mode is reserved for advanced users and is popular in sports conditioning programs for basketball, soccer, and skiing athletes who need to replicate the unpredictable contact forces of competition ^[3]. From a pure core training perspective, plank variations performed with hands on the flat side of an inverted BOSU produce among the highest recorded levels of transverse abdominis and oblique activation of any balance board exercise modality ^[1]. The primary trade-off is bulk: at 26 inches in diameter and approximately 15 lbs., the BOSU requires dedicated storage space and cannot double as a standing desk accessory. For home gyms and professional training environments, no single piece of balance equipment delivers more training variety ^[6].

Balance Board Buying Guide

How to Choose the Right Board for Your Goals#

Selecting the right balance board comes down to matching the board's mechanism, difficulty level, and intended use context to your specific goals and current fitness level. The market offers four primary board types - wobble boards, rocker boards, roller boards, and 360-degree spring-loaded boards - each with distinct training characteristics and optimal use cases. Overlaying this is the question of context: are you training in dedicated workout sessions, using the board passively at a standing desk, performing sport-specific conditioning, or recovering from a lower-limb injury ^[7]? The following criteria will help you make a confident and well-informed decision.

Board Type: Wobble boards (like Yes4All) use a hemispherical base for 360° tilt - ideal for beginners and rehab. Rocker boards tilt on a single axis. Roller boards (like Indo Board) place a deck atop a free-rolling cylinder for high-challenge dynamic instability. Spring-loaded boards (like Revbalance 101) combine controlled 360° movement with adjustable resistance for progressive difficulty.
Difficulty and Adjustability: Beginners and rehab patients should start with a wobble or rocker board offering a tilt range of 10–15°. Intermediate users benefit from roller boards or mid-resistance spring platforms. Advanced users can challenge themselves with the Indo Board's free roller or the flat-side-up BOSU. Adjustable boards (Revbalance 101, BOSU) grow with you over years.
Weight Capacity: Always choose a board rated at least 50 lbs. above your body weight to ensure structural safety and long-term durability. StrongTek leads the field at 350 lbs.; Revbalance 101 and Yes4All both support 300 lbs.; Indo Board is rated for 250 lbs.
Surface Grip and Non-Slip Coating: Essential for safety during dynamic use. Look for grip tape (Indo Board), textured non-slip surfaces (Yes4All, StrongTek), or textured dome material (BOSU). Bare feet generally provide the best board feel; socks significantly increase slip risk on most surfaces.
Intended Use Context: Standing desk users need a quiet, low-profile board with controlled movement - the StrongTek or Revbalance 101 are the optimal choices. Workout-focused users need a board that challenges them within dedicated sessions - Indo Board, BOSU, or Revbalance 101 are best. Rehab patients should begin with a wobble board under clinical guidance before progressing.
Portability and Storage: Wobble boards and roller boards are the most portable options at under 5 lbs. with a flat storage profile. The BOSU is the largest and heaviest at approximately 15 lbs. and 26 inches diameter. Consider whether you need to store the board between sessions or can leave it in a permanent position.
Durability of Materials: Solid maple (Indo Board) and crossed hardwood (StrongTek) offer superior multi-year longevity. MDF construction (budget wobble boards) is adequate for light use. Commercial-grade BOSU construction is engineered for high-volume multi-user gym environments.
Price-to-Value Ratio: Budget tier: $25–$40 (Yes4All). Mid-range: $130–$175 (Indo Board, BOSU). Premium: $170–$260 (StrongTek, Revbalance 101). Higher price generally correlates with better build quality and progressive difficulty range rather than absolute core activation intensity at any single setting.
Included Training Resources: BOSU and Indo Board benefit from large communities and extensive online training libraries. Revbalance 101 includes structured progression guides with purchase. Yes4All provides minimal guidance, requiring independent research into exercise progressions and beginner protocols.
Stability for Seniors and Rehabilitation: For fall prevention and post-injury rehab, prioritize limited tilt range (10–15°), a stable base design, and a high weight capacity. The Yes4All, StrongTek, and dome-side BOSU are the most appropriate options for these populations. Always train near a wall for additional safety during the first several weeks.

Editor’s Note

Pro Tip: Start With 10 Minutes Per Day, Not 30

Regardless of which balance board you choose, consistency matters far more than session length when starting out. Begin with 10-minute daily sessions focused solely on maintaining your balance - no additional exercises layered on top. Research shows this focused proprioceptive practice produces measurable improvements in postural sway within two to four weeks of consistent daily practice. Once standing is effortless, layer in bodyweight squats, shoulder presses, and other compound movements to progressively increase training demand. Always use a wall or sturdy furniture for support during your first several sessions, especially with roller-style boards. Wearing athletic shoes rather than socks significantly reduces slipping risk on any board type during early training.

Editor’s Note

Important Safety Note for Rehabilitation Users

If you are using a balance board as part of recovery from an ankle sprain, ACL reconstruction, or other lower-limb injury, always consult your physical therapist or physician before beginning unsupervised balance board training. Clinical rehabilitation protocols typically introduce balance boards in supervised settings with carefully incremented difficulty progression. Starting with a roller-style board or advanced spring-loaded platform during early recovery significantly increases re-injury risk. The Yes4All wobble board or dome-side BOSU are generally the appropriate entry points for post-injury rehab, but professional guidance is essential before progressing to any dynamic board type.

Key Takeaway

The Yes4All Wooden Wobble Balance Board is the best choice for absolute beginners. Its 15° tilt range and hemispherical base provide meaningful balance training without the steep learning curve of roller or spring-loaded boards, and its $25–$40 price makes it a risk-free first step into balance training.

Frequently Asked Questions

What is the best balance board for core training in 2026?

The Indo Board Original Training Package is our top overall pick for core training in 2026. Its roller-and-deck mechanism creates the most demanding instability challenge of any board in our roundup, forcing continuous activation of the deep core stabilizers including the transverse abdominis, multifidus, and obliques. For users who want adjustable difficulty from beginner to advanced on a single board, the Revbalance 101 v2 is an excellent alternative. The BOSU Pro earns consideration for anyone who wants the most exercise variety in a single piece of equipment.

What is the difference between a wobble board and a rocker balance board?

A wobble board uses a hemispherical base - essentially a rounded dome - that allows the board to tilt in all 360 directions simultaneously. This is the design used by the Yes4All board. A rocker board uses a curved base that allows movement on a single axis only, either front-to-back or side-to-side. Wobble boards are generally considered more comprehensive for beginner proprioceptive training because they force multi-planar corrections, while rocker boards can be easier to control by limiting movement to one axis. Both types activate core and ankle stabilizers effectively, but wobble boards typically provide more complete multi-directional training stimulus.

Are balance boards good for back pain and lumbar strengthening?

Yes, with important caveats. Balance board training has been shown to activate the deep lumbar stabilizers - particularly the multifidus and transverse abdominis - that play a critical role in spinal health and injury prevention. Research published in the Journal of Strength and Conditioning Research demonstrates significant core muscle activation improvements following structured balance board training programs. However, individuals with acute back pain, herniated discs, or spinal stenosis should consult a healthcare provider before using any balance board, as the postural demands can aggravate certain conditions. For general lumbar strengthening and injury prevention in healthy adults, balance boards are an excellent adjunct to a core exercise routine.

Can I use a balance board at a standing desk all day?

You can, but a thoughtful rotation approach produces the best outcomes. Research on balance board ergonomics indicates that prolonged continuous use beyond 30–45 minutes can increase lower-limb fatigue and reduce work performance, so alternating between standing on the balance board, standing flat on the floor, and sitting is the most sustainable strategy. The StrongTek Professional Wooden Balance Board and Revbalance 101 v2 are the best choices for standing desk use because their controlled movement profiles do not demand focused conscious attention during cognitively demanding work. Roller-style boards like the Indo Board require too much active balance management for productive work. Start with 15–20 minute intervals and extend duration gradually as lower-limb endurance improves.

What is the best balance board for beginners with no fitness experience?

The Yes4All Wooden Wobble Balance Board is the ideal starting point for complete beginners. Its 15° tilt range is challenging enough to provide genuine training stimulus without creating injury risk or discouragement from excessive difficulty. The $25–$40 price means beginners can try balance board training without a significant financial commitment. Once you can comfortably stand and perform basic squats on the Yes4All for 15 minutes without holding a wall, you are ready to progress to a more demanding board such as the Revbalance 101 v2 or the Indo Board Original.

Do balance boards actually help with surfing and skateboarding?

Yes - this is one of the most evidence-supported applications of balance board training. Roller-style balance boards like the Indo Board were originally developed specifically for off-season surf training and have been used by professional surfers for over three decades. The lateral weight-shifting, edge-to-edge control, and hip counterbalancing patterns practiced on a roller board directly translate to wave riding and skateboard carving mechanics. Off-season balance board training helps maintain and develop the sport-specific proprioceptive skills that erode during periods away from the water or skatepark. The Indo Board remains the gold standard for this application, though the Revbalance 101 v2 is also effective for developing the rotational balance demands of both sports.

What is the best balance board for seniors to prevent falls?

For seniors focused on fall prevention, the BOSU Pro Balance Trainer (dome-side up) or the Yes4All Wooden Wobble Balance Board are the most appropriate choices. Research published in the Physical Therapy Journal confirms that structured balance board training significantly reduces fall incidence in older adults by improving proprioception, reaction time, and hip abductor strength over 6–8 week programs. The key principles are choosing a board with a limited, predictable movement range and always training adjacent to a wall or stable surface. The BOSU's soft inflatable dome provides a forgiving surface that reduces the severity of balance errors during practice itself. The Yes4All's low cost also makes it accessible to seniors on fixed incomes who want to begin a fall prevention program.

How long should I practice on a balance board each day to see results?

Most peer-reviewed research protocols showing significant improvements in balance performance and core strength use 15–30 minutes of balance board training per day over 4–8 weeks. However, you do not need marathon sessions to see results: three sets of 5-minute balance holds with 60-second rest periods delivers most of the adaptation benefit of a single longer session. Consistency is more important than duration - daily 10-minute sessions will outperform three 30-minute sessions per week for proprioceptive nervous system adaptation. As your skill level plateaus, increase the challenge by adding upper-body movements, closing your eyes, or transitioning to a more demanding board type rather than simply extending session duration, which yields diminishing returns.