This dumbbell ab workout builds core strength and burns fat in just 25 minutes

If you want to develop your abs, traditionally, the advice has always been to do endless crunches and sit-ups. These are practical exercises, but you can strengthen your core and build ab muscle in a more varied way with this 25-minute strength workout.

While you could use the best ab rollers to help develop strength in your mid-body, this short routine contains some top core strengthening exercises with dumbbell exercises designed to build lean muscle.

For when you're training at home, all you'll need is a set of the best adjustable dumbbells. These customizable weights combine several dumbbells in one for a space-saving way to build muscle without leaving the house.

As useful as they are, the weights can be expensive. There are dumbbells on sale throughout the year, but you can also save money on this muscle-building equipment right now with these two deals on today. 

Bpulse 27.5lb Adjustable Dumbbell | was $70.99, now $60.34 at Amazon

This customizable weight is adjustable from 5lbs to 27.5lbs and comes with a base for easy storage. It combines five fixed weight dumbbells and you can quickly change the load by turning the center of the non-slip handle. Save 15% before the deal ends. 

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NordicTrack Select-A-Weight 25lb Adjustable Dumbbell Set | was $199.99, now $139.99 at Best Buy

NordicTrack's weights are some of the highest quality around, and now you can pick up a set of the company's dumbbells for less than $150. They're adjustable in 5lb increments up to 25lbs and come with a free 30-day membership to the iFit virtual workout app. Don't miss out on this $60 saving right now. 

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For those training at the gym, you'll want to get a pair of dumbbells that challenge you but aren't so heavy that they affect your form. If you're not sure where to start, check out these beginner strength training tips before starting.

Once you have weights by your side, you can take on this ab-focused workout from fitness YouTubers Tiff x Dan. The routine is arranged in trisets (groups of three exercises performed without breaks), alternating between dumbbell and bodyweight sets.

Trisets are a great way to maximize the efficiency of your training. Not only does it mean your muscles have to work harder before they get a rest, but taking fewer breaks also means you get through the routine faster.

Watch Tiff x Dan's 25-minute ab workout

According to a study published in the International Journal of Exercise Science, triset training leads to more significant muscle swelling than traditional resistance training. The researchers note this increased swelling may lead to increased muscle growth too.

Tiff x Dan's routine blends this training style with cardio-focused and weight-based exercises. The dumbbell moves help build strength, while the cardio activities are designed to raise your heart rate.

Sustaining this elevated heart rate helps boost your metabolism—the amount of energy you burn at rest—which leads to all-day fat-burning. This is useful if you want to lose weight or if you're hoping to develop six-pack abs.

You need to strengthen your muscles and lower your body fat to achieve visible abs. You can't spot-target fat in specific areas, so you'd need a fat-burning routine like Tiff x Dan's or a HIIT workout for fat loss to see results.

If you're after another way to build muscle and burn fat with weights, pick up one of the best kettlebells and learn how to do kettlebell swings. This compound exercise develops strength all over, raises your heart rate, and works your core.