First off, it is impossible to “spot reduce”, that is to lose fat from a specific area. When you do exercises that target a specific area, you’re actually targeting the muscles (not fat!) in that area. That means you’re doing step 2, which is increasing the shape and firmness of your arms by toning your arm muscles. That will get you some results, but fighting jiggly arms requires more than just spot exercises!  
What we eat can also play a part in the extent of the jiggle so eating a good, healthy balanced diet as well as keeping well hydrated can put you on the right track. Resistance exercises are the most effective way to blast that underarm fat as well as strengthen, shape and tone your muscles. You can always go down to the gym and work up a sweat but who has time for that? If you want a convenient and quick alternative then you can easily manage an effective routine in the comfort of your own home. All you need is a set of dumbbells and you can start toning up those bingo wings with these 10 easy workouts.

Think you can’t get a good workout while you’re sitting? Think again. In fact, the seated lat pulldown is one of the best exercises for toning those arms in a hurry. Using a pulldown machine, grip the bar and pull to chest level, and then raise again. This exercise makes it easy to build your biceps quickly and helps strengthen and tone your shoulders, which can make your arms look leaner, as well.
In case you’re curious, I’ll take a quick minute to share a little bit about who I am, my experience with struggling with my weight, what I did about it, and my purpose for helping folks all over the world do the same... I've found that what brings me the most happiness are the real people with real lives I've helped, as they email me about the success they've had using my techniques... read more

The workout includes a dynamic warm-up to get your blood flowing and prep your body for the rest of the work ahead, and a cool-down to help you slow back down and wrap it all up. If you want to make the workout more challenging—maybe you've done it a handful of times and are ready to turn things up a notch—add weights to the lunge and squat movements. You can also, like Sims said, add another round of the main strength circuit.
Do the standing "V" raise. The standing "V" raise can help you burn fat while working your shoulder muscles. Pick up a dumbbell with each hand and stand with your feet shoulder-width apart. Start with your arms at your sides and slowly raise them upwards in a diagonal "V" shape. Keep your arms straight and bring them up until they are parallel to the floor. Hold this pose for one second, then lower your arms. Do 2-3 sets of 12-15 reps.[3]

Essentially, circuit weight training, or circuit bodyweight training, burns more calories than interval training, and that in turn burns WAY more calories than steady cardio. When you strength train, you burn calories. Then, your body needs to spend hours and hours afterwards rebuilding your muscles, which in turns burns even more calories (they call this the ‘afterburn effect).

In addition to the direct beneficial effects of exercise on the heart, regular exercise also improves several important cardiac risk factors. Exercise lowers blood pressure, helps prevent obesity, reduces triglyceride levels, increases HDL cholesterol levels, and improves insulin resistance (and thus helps to prevent or even reverse metabolic syndrome ). An exercise routine has even been shown to be helpful in achieving smoking cessation.
Get down on all fours with your knees placed directly below your hips and palms placed directly below your shoulders. Now, raise your right arm forward and stretch your left leg backward at the same time. Create a tension in your back by flexing your foot. Hold the position for a few seconds and then come back to the starting position. Repeat the same using your left arm and right leg. Repeat 15 to 20 times on both sides.
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