21-Day Arm Workout Challenge
Strengthen Your Arms and Shoulders With This 3-Week Dumbbell Challenge


Strengthen Your Arms and Shoulders With This 3-Week Dumbbell Challenge
After following this 21-day dumbbell arm challenge created by NASM-certified personal trainer Désirée Triolo, it's pretty much guaranteed you'll feel stronger. Don't worry if you've never lifted a dumbbell in your life; this arm plan was designed with everyone in mind, whether it's your first time working out or you exercise regularly.
This dumbbell arm challenge leverages a simple arm workout that consists of five basic dumbbell exercises. The moves target your biceps, triceps, back, and shoulders to build overall upper-body strength. Over the course of the challenge, you'll increase the number of reps you're doing of each exercise, eventually working up to three sets of 15 reps of each.
Ahead, you can find a detailed explanation of how to do each of the five arm exercises, followed by the three-week plan. The first step is choosing the appropriate weight — Triolo says you want a dumbbell that fatigues your muscles by the end of the last two reps. She suggests beginners start with five-pound dumbbells and more advanced lifters go heavier at 15 to 25 pounds. If the challenge ever feels too easy (because you're gaining strength!), that's your cue to increase the weight of the dumbbells. Likewise, if you find your muscles are fatiguing too early or your form becomes compromised, decrease the amount of weight you're lifting.
This arm challenge incorporates two rest days per week — because even though it's a challenge, recovery days are always important. "My professional opinion is to alternate upper-body and lower-body training days to improve your overall fitness level and to avoid creating muscle imbalances," Triolo says, which is why you'll see "lower body" listed on the plan. On these days, you can do lower-body exercises (like this dumbbell butt workout) or walk, run, bike, or hike.
3-Week Arm Workout Challenge
Equipment needed: Dumbbells
Directions: After warming up for a few minutes with some neck circles, Cat and Cow, and arm circles, perform all five of the dumbbell exercises listed below for the designated number of reps and sets. After each day's workout, run through these upper-body stretches.
- Hammer curl
- Bent-over row
- Overhead shoulder press
- Upright row
- Triceps kickback
Day | Reps |
---|---|
Day 1 | 3 sets of 8 reps of each exercise |
Day 2 | Lower body |
Day 3 | Rest |
Day 4 | 3 sets of 8 reps of each exercise |
Day 5 | Lower body |
Day 6 | Rest |
Day 7 | 3 sets of 10 reps of each exercise |
Day 8 | Lower body |
Day 9 | Rest |
Day 10 | 3 sets of 10 reps of each exercise |
Day 11 | Lower body |
Day 12 | Rest |
Day 13 | 3 sets of 12 reps of each exercise |
Day 14 | Lower body |
Day 15 | Rest |
Day 16 | 3 sets of 12 reps of each exercise |
Day 17 | Lower body |
Day 18 | Rest |
Day 19 | 3 sets of 14 reps of each exercise |
Day 20 | Rest |
Day 21 | 3 sets of 15 reps of each exercise |
Keep reading for instructions on how to do the five different arm exercises.