Choosing the Right Medicine Ball Size
Medicine balls are versatile training tools used for strength, power, and core development. Choosing the right medicine ball depends on your fitness level, the exercises you plan to perform, and whether you need a ball that bounces or absorbs impact. Medicine balls range from 2 to 50 pounds, with most people using balls between 6 and 20 pounds. Unlike dumbbells where you select weight based purely on strength, medicine ball weight must account for the dynamic, explosive nature of exercises like slams, throws, and wall balls.
Medicine ball diameter typically correlates with weight. A 6 pound ball measures approximately 9 inches in diameter, while a 20 pound ball measures 12 to 13 inches. This relationship between weight and size affects how the ball feels in your hands and how easy it is to grip during exercises. Smaller, lighter balls can be palmed with one hand, while heavier balls require two handed grips. The size also affects range of motion during exercises like overhead slams, where a larger ball creates more resistance at the top of the movement.
History and Standards in Medicine Ball Design
Medicine balls date back thousands of years, with ancient Greek physician Hippocrates using animal skin balls filled with sand for injury rehabilitation. The term medicine ball emerged in the late 1800s when American fitness pioneer William Muldoon popularized weighted ball exercises for health and conditioning. Early medicine balls were made of leather stuffed with rags, horsehair, or sand, weighing between 5 and 15 pounds. These balls did not bounce, making them ideal for core strengthening and partner passing drills.
Modern medicine balls evolved significantly in the 1990s with the rise of functional fitness and sports performance training. Manufacturers began producing specialized ball types for different purposes. Slam balls with thick rubber shells and sand filling were developed for high impact slamming without bouncing. Wall balls with soft vinyl covers became standard in CrossFit for wall ball shots. Bouncing medicine balls using rubber construction enabled plyometric exercises. Today, medicine balls are categorized by type, weight, and surface material rather than a single universal standard.
Common Medicine Ball Types Explained
Traditional medicine balls have leather or vinyl covers filled with sand, gel, or fiber. They have little to no bounce, making them suitable for core exercises, weighted sit ups, and controlled partner tosses. These balls typically range from 4 to 30 pounds and measure 9 to 14 inches in diameter. The soft outer surface provides a comfortable grip and can be caught safely during partner drills. Traditional medicine balls are the most versatile option for general fitness and strength training.
Wall balls are specifically designed for the CrossFit wall ball exercise, where you perform a squat and throw the ball upward against a wall at a target 9 or 10 feet high. Wall balls have soft, durable vinyl or fabric covers that absorb impact without damaging walls. They are slightly larger in diameter than traditional medicine balls of the same weight, making them easier to catch. Wall balls typically range from 6 to 30 pounds, with 14 and 20 pound balls being most common for CrossFit workouts. The soft construction makes wall balls comfortable but less suitable for slamming.
Slam balls are built for maximum durability during overhead slams. They have thick rubber shells filled with sand or iron pellets that prevent bouncing. The heavy duty construction allows you to slam the ball forcefully without fear of rupture or excessive bounce. Slam balls range from 10 to 50 pounds and are smaller in diameter than wall balls of equivalent weight due to their dense filling. The textured rubber surface provides excellent grip even when wet. Slam balls are ideal for power development but too heavy and firm for most core exercises.
Weight Selection Guidelines
Beginners should start with 6 to 10 pound medicine balls for most exercises. This weight allows proper form during dynamic movements without excessive fatigue. A 6 to 8 pound ball works well for core exercises like Russian twists and weighted sit ups, while an 8 to 10 pound ball suits wall balls and partner passes. Starting too heavy compromises form and increases injury risk, particularly during rotational exercises that stress the spine. As strength and conditioning improve, gradually increase weight by 2 to 4 pound increments.
Intermediate athletes typically use 10 to 16 pound medicine balls for most exercises. A 12 pound ball is versatile enough for core work, wall balls, and moderate intensity slams. Women often prefer 10 to 14 pound balls for wall balls, while men commonly use 14 to 20 pounds. For overhead slams and power exercises, intermediate users can handle 15 to 25 pounds depending on upper body strength. Having two balls at different weights allows you to match the load to the exercise intensity and volume.
Advanced athletes and strength trained individuals use 16 to 30 pound medicine balls for most exercises. CrossFit prescribes 20 pound wall balls for men and 14 pounds for women in competition workouts. Overhead slams may use 25 to 40 pounds to develop maximum power output. Extremely heavy slam balls up to 50 pounds are used by professional athletes and strongman competitors for explosive strength development. At advanced levels, medicine ball weight should challenge power output without reducing speed so much that the exercise becomes a slow grind.
Exercise Specific Considerations
Wall ball shots require a ball heavy enough to build strength but light enough to maintain speed through high repetition sets. The standard CrossFit wall ball weights of 14 pounds for women and 20 pounds for men represent a good balance. The ball must travel at least 9 feet vertically, so excessive weight prevents hitting the target consistently. Wall balls should have soft covers and be slightly oversized to cushion catches after rebounding off the wall. Using a slam ball for wall balls damages walls and hurts your hands.
Overhead slams prioritize power development, requiring heavier balls than most other exercises. The goal is to generate maximum force by explosively slamming the ball into the ground. Slam balls between 20 and 40 pounds work best, as they provide enough resistance to require full body engagement while allowing explosive speed. Lighter balls feel too easy and do not build power effectively. Heavier balls slow the movement too much, turning slams into a strength grind rather than power exercise. Always use a true slam ball, not a traditional medicine ball or wall ball, as these may rupture.
Core exercises like Russian twists, woodchoppers, and weighted sit ups use lighter medicine balls than slams or wall balls. A 6 to 12 pound ball suffices for most people, as core exercises involve sustained tension and higher repetitions. Going too heavy compromises form and shifts stress from the core to the arms and shoulders. The ball should be small enough to hold comfortably at arm's length during rotational movements. Traditional medicine balls work best for core training due to their comfortable grip and moderate size.
Size and Diameter Considerations
Medicine ball diameter affects grip and handling during exercises. Small balls under 9 inches in diameter can be gripped with one hand, allowing single arm exercises like single arm slams or rotational throws. Medium balls from 9 to 12 inches require two hands for most exercises but remain easy to control. Large balls over 12 inches become unwieldy and difficult to grip securely, limiting exercise variety. The diameter should match your hand size and the intended exercises.
Circumference is another useful measurement, as it indicates how far your hands must reach around the ball. A 10 inch diameter ball has a 31 inch circumference. If you cannot reach at least halfway around the ball comfortably, it may be too large for secure gripping. People with smaller hands should choose balls on the smaller end of the diameter range for a given weight. Manufacturers sometimes offer compact versions of heavier balls, using denser filling to achieve more weight in a smaller package.
Material and Construction Differences
Leather medicine balls are traditional and durable, with a comfortable natural feel. They develop a worn patina over time that some users prefer. Leather balls typically cost more than vinyl and require occasional conditioning to prevent drying and cracking. They are best for indoor use, as moisture and extreme temperatures damage leather. Leather balls are less common today but remain popular among purists who appreciate the classic aesthetic and feel.
Vinyl covered medicine balls are the most popular modern option. Vinyl is durable, easy to clean, and affordable. It resists moisture and can be used outdoors without damage. Vinyl balls come in various colors, making it easy to organize sets by weight. The smooth vinyl surface provides adequate grip when dry but can become slippery when wet. Textured vinyl improves grip in sweaty conditions. Vinyl balls are suitable for all general medicine ball exercises except heavy slamming, which may rupture seams over time.
Rubber medicine balls have textured surfaces for superior grip and are built for durability. Solid rubber slam balls withstand years of heavy use without splitting or losing shape. Rubber construction adds weight, so rubber balls tend to be denser and smaller than vinyl balls of the same weight. The firm rubber surface is less comfortable for catching but excels in grip security. Rubber balls are ideal for outdoor training and high intensity programs where equipment takes heavy abuse.
Practical Tips for Medicine Ball Selection
If you can only buy one medicine ball, choose a weight in the middle of your capability range. For most people, a 10 to 12 pound traditional medicine ball or wall ball covers the widest variety of exercises. This weight challenges core work without being overwhelming and works for moderate intensity slams and throws. As your budget allows, add a lighter ball for high repetition core work and a heavier slam ball for power training. A three ball set of 8, 12, and 20 pounds provides excellent versatility.
Test the ball's grip and size before buying if possible. Hold the ball at arm's length and perform a few twisting motions to ensure you can control it comfortably. Check that the seams are reinforced and the surface has no defects. Inflate balls properly if they have air valves, as under inflated balls feel mushy and over inflated balls become too firm. Store medicine balls away from direct sunlight and extreme temperatures to prolong their lifespan. Clean vinyl and rubber balls regularly with mild soap to prevent odor buildup from sweat.