Choosing a Medicine Ball

A Formula for Calculating the Right Medicine Ball Weight

If there was one piece of fitness gear I couldn’t have done without during this last year of re-imagined exercise plans, then a simple medicine ball would definitely be the daily spoonful that I couldn’t have survived without.

Medicine balls are a highly effective, compact and cost efficient addition to any home gym. You can easily grab one to make a range of bodyweight exercises more challenging and they are especially great sport specific training aids as they can be used in all planes of motion to replicate stresses that are common in most sports: rotating under load, thrusting from the shoulders or hips, throwing and catching, for example. 

Because medicine balls can be released at the end of a repetition and thrown, they are great for building explosive power that emphasise a full range of movement. As such, they can also be used to factor in a cardio element to resistance based workouts. Heavier balls and fewer repetitions can be used to build strength, while lighter weights are better for endurance based workouts, where the reps are higher and speed is key.

Choosing a medicine ball can be tough – there’s a lot of choice out there. Despite the obvious disparities in weight – which I will get to in a minute – they come in different sizes and materials, including some with handles and even ropes attached. Do you want a ball that bounces, or one that definitely doesn’t? (a ‘slam’ ball), one that’s easy to catch, or one that’s easy to hold without dropping? One that looks like a giant dog toy? Too much choice is no choice at all!

Medicine balls come in three types of material:

1. Traditional leather bound

Good, general purpose balls that should provide controllable rebound against a wall, for example. These aren’t designed with high bounce in mind, as this would be difficult to control. The leather and stitching can potentially wear quicker than a rubber ball with welded seams, but that will depend on build quality, too. I favour leather balls as they are one less piece of plastic in the world, though whether the entire production and supply chain is more eco-friendly is another question.

2. Rubberised

Can be a fairly neutral bouncing ball as per the old school standard leather model, or specifically designed to bounce or, alternatively – not to bounce at all. This is basically a slam ball and is designed to be released with maximum force in close proximity, without fear of rebound and the potential for broken noses, windows, and dreams 😊

3. Hard shell plastic

These are generally the types with handles, that aren’t meant to be thrown – and definitely not against a hard surface. They are obviously much easier to keep hold of with sweaty hands, but score low on versatility and are often a bit cheaper.

The physical dimensions of any medicine ball will be determined by the weight of the material it is made with and its specific design. Generally, balls with larger surface areas are favoured for throwing and catching.

Selecting the right medicine ball weight is key

The most important thing is to choose a weight that allows good form through a full range of motion. For example, if you are rotating, throwing and receiving the ball as it rebounds off a wall, then you should be able to control the chosen weight with good rotation of the torso, without fear of injury, for the full range of repetitions. For endurance and speed, that may be 15-20 reps. For strength or power, then a heavier weight for 8-10 reps would be the target. The thing to get right here is: don’t go too heavy. If you want a big lump, grab a kettlebell instead (but definitely don’t throw it without fair warning 😊)

Formula for selecting the right medicine ball weight:

(Body weight / 2) x 0.1 = Medicine ball weight

So for a 70kg person, that would be:

(70 / 2) x 0.1 = 3.5kg

(You can use kg or lb)

This is an approximate guide and will depend on your current strength level and training history. When you are catching a ball at velocity (in an overhead catch, for example) even a lower weight ball can place large stresses on small muscle groups.

If you can, try a few different weights out. Like any exercise, start light and increase weight slowly over time as you get stronger. Remember, the beauty of medicine balls is that speed and a full range of movement are the main advantages of using them in the first place. 

About the author
Dean is a full-time fitness enthusiast and a qualified personal trainer in Godalming, UK