Guide
Water-Filled Weights: How They Work, Cost and Compare
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Water-filled weights are hollow, refillable weights that you fill with tap water to the load you want and empty to store. A pound of water loads your muscles like a pound of iron, and the moving water adds a stability challenge. AguaForce makes one with three handles that adjusts from 1 to 11 lb, at $39 for a set of 2.
What are water-filled weights and how do they work?
Water-filled weights are plastic shells you fill with water to set the load. Water weighs 1 kg per liter (2.2 lb), so the more you add, the heavier the weight gets, and pouring it out makes it light enough to store or carry. An AguaForce weight has three handles, a leak-proof plug-seal cap and fill lines molded into its translucent body.
Do water-filled weights work as well as metal weights?
Yes, within their weight range. A pound of water loads your muscles exactly like a pound of iron. The difference is that water moves, so your core and stabilizing muscles work on every rep to keep the weight steady, and slow, controlled movements work best. AguaForce tops out at 11 lb per weight, so it suits toning, strength building, mobility and everyday fitness, not heavy lifting.
How do you fill a water weight to an exact weight?
Fill it to the molded line for the weight you want. AguaForce's fill lines, in lb and kg, show the total weight including the 0.8 lb jug, and you can see the water level through the translucent body. Without the lines, subtract 0.8 lb from your target and measure that much water: a liter weighs 2.2 lb and a US cup about 0.52 lb.
| Total weight | Water to add | Liters | US cups |
|---|---|---|---|
| 1 lb | 0.2 lb | 0.09 L | 0.4 |
| 2 lb | 1.2 lb | 0.54 L | 2.3 |
| 3 lb | 2.2 lb | 1.00 L | 4.2 |
| 5 lb | 4.2 lb | 1.91 L | 8.1 |
| 8 lb | 7.2 lb | 3.27 L | 13.8 |
| 10 lb | 9.2 lb | 4.17 L | 17.6 |
| 11 lb | 10.2 lb | 4.63 L | 19.6 |
You can raise the load in steps as small as half a cup of water, about 0.26 lb, instead of jumping between fixed sizes such as 5 and 8 lb.
What exercises can you do with water-filled weights?
You can train your whole body: arms, chest, back, abs, glutes and legs. Hold one by its top handle like a kettlebell for swings and goblet squats, use two like dumbbells for curls, presses and lateral raises, or grip both side handles for crunches, squats and Pilates.
- Lower body: Front squat, Sumo squat, Forward lunges, Romanian deadlift, Glute bridge, Swing
- Core: Russian twist, Overhead crunch, Side bend, Halo
- Upper body: Bent over row, Armpit row, Lateral raise, Shoulder press, Alternate biceps curl, Triceps kickback
Every set comes with exercise cards, and the free AguaForce exercise library shows how to do all 36 exercises and which muscles each one works.
Water-filled weights vs dumbbells, kettlebells and foam aquatic dumbbells: which is better?
It depends on how heavy you need to go and where you train. Fixed dumbbells and kettlebells suit heavy lifting but need one piece for every weight. Foam aquatic dumbbells only work in a pool. Water-filled weights cover a light-to-moderate range with one adjustable pair, work on land and in the pool, and weigh under 1 lb empty.
| AguaForce water-filled weight | Fixed dumbbells | Kettlebell | Foam aquatic dumbbells | |
|---|---|---|---|---|
| Weight range | 1–11 lb each, set with water | One fixed weight per pair | One fixed weight | Nearly weightless; resistance comes from buoyancy |
| Changing the weight | Add or pour out water | Buy another pair | Buy another kettlebell | Buy another pair |
| Weight when stored | 0.8 lb empty | Full weight | Full weight | Nearly weightless |
| Where it works | On land and in the pool | On land | On land | In the pool |
| Grip | Three handles: one on top, two on the sides | One handle each | One handle | One bar each |
| Floors | Plastic, with no metal edges | Metal can dent or scratch floors | Metal can dent or scratch floors | Soft foam |
| Price | $39 for a set of 2 | Paid per weight | Paid per weight | Paid per resistance level |
How much do water-filled weights cost?
AguaForce costs $39 USD for a set of 2, with free shipping to the US and Canada and free returns within 30 days. Sales tax is calculated at checkout. Because each weight covers every weight from 1 to 11 lb, one pair replaces several pairs of fixed dumbbells, which are bought one weight at a time.
Are water-filled weights good for seniors, beginners and small spaces?
Yes. They start very light and go up in steps as small as half a cup of water, which suits beginners and older adults. They have no hard metal edges to dent floors or bruise toes, and empty they weigh under 1 lb and fit on a closet shelf, which suits apartments, dorms and other small spaces.
- Seniors: arthritis-friendly handles, seated exercises and a drop-safe design.
- Beginners: light starting weights, small steps up and easy-to-read fill lines.
- Small spaces: quiet workouts that won't scratch floors, and storage in a drawer.
- Group fitness: one weight that each participant fills to their own level.
Are water-filled weights good for travel?
Yes. Empty, an AguaForce weight weighs 0.8 lb and measures 12.3 × 4.7 × 13.7 in (31.2 × 12 × 34.7 cm), so it fits in a backpack or suitcase. Fill it with tap water wherever you land and empty it before you pack up. Customers take theirs to second homes, RVs and the beach.
Do water-filled weights leak, how durable are they, and does the sloshing get in the way?
AguaForce's plug-seal cap locks watertight, and reviewers consistently report zero leaks. The body is thick, impact-resistant HDPE plastic that won't rust and isn't affected by pool chlorine or salt water; just empty it before leaving it anywhere below freezing. The water does move, which works your core, and slow, controlled movements keep it steady. A 30-day money-back guarantee covers breakage.
Can you use water-filled weights in the pool?
Yes, in shallow and deep water. When the weight stays mostly underwater, use it empty: it floats, so buoyancy and drag provide the resistance. When it comes mostly out of the water, as in lateral raises, fill it. Chlorine and salt water don't affect it, and it won't damage a pool floor if dropped.
Aquatic instructors can see AguaForce for pool classes and request a free demo set for their pool.
How often should you strength-train with water-filled weights?
At least 2 days a week, working all the major muscle groups (legs, hips, back, abdomen, chest, shoulders and arms), according to the CDC's physical activity guidelines for adults. Adults 65 and older should also do balance activities. Most beginners do well with two or three sessions a week and a rest day between strength workouts.
See the CDC's recommendations for adults and for adults 65 and older. Check with a doctor or physiotherapist before starting a new exercise program.
Where can you buy water-filled weights in the US?
AguaForce sells online at aguaforce.com, with free shipping to the US and Canada, and on Amazon. Studios, gyms, pools and retailers can buy any quantity through the wholesale program, and pools and aquatic facilities can request a free demo set.
- Buy the AguaForce 2-pack for $39
- AguaForce on Amazon
- Wholesale pricing for studios, gyms, pools and retailers
Sources
- CDC, Adult Activity: An Overview
- CDC, Older Adult Activity: An Overview
- U.S. Geological Survey, Water Density
- AguaForce product specifications, in the 2-pack details