Underarm Flab Frustration: The Gym Mistake That’s Keeping You From Sexy Arms

If I’ve heard it once, I’ve heard it a thousand times—women want sexy, sleek, toned arms and are willing to do just about anything to get them. But what if I told you doing that 10th set of tricep extensions was NOT, in fact, going to reduce the amount of flab under your arms… but instead would just develop the muscle and potentially grow the area? It’s actually true!


One of the biggest mistakes I see most women making with their arm workouts is trying to reduce their underarm flab by doing excessive tricep extensions. Ahhh…when I see this, I want nothing more than to scream from the mountaintops: No amount of weight lifted or number of reps completed will get rid of flabby arms! In fact, the heavier the weight, the more muscle you will build…making the tricep region appear even larger than it did before! Seriously, by doing this, you are just expanding the muscle—you are NOT burning the fat in that region—so that same pesky layer will be there no matter what tricep-focused lifts you do.

Unfortunately, you can’t spot reduce fat. Trust me, I wish I was lying about this one. But don’t lose hope—there are plenty of ways to get those sexy sculpted arms of your dreams… AND it’s surprisingly simple. The key to decreasing that underarm flab….(you ready for this?)…. is all about what you eat and about building the muscles around the underarm flab to create the illusion of slimmer triceps.

We often get so fixated with the old-school body building mentality that we need to do bicep curls and tricep extensions to sculpt those limbs, all the while, we are neglecting the most important muscle groups that actually help create the appearance of a slim and sculpted arm: The shoulders and the back. By focusing more on compound movements that fire your back and shoulder muscles first, you will automatically (and secondarily) work the appropriate bicep and tricep muscles without risking overdeveloping your arms.

Think about it like this: The nicer the shoulder boulder, the slimmer the arm appears. I’ll bet you’ve never seen a woman with nice shoulders who didn’t have amazing arms as well—they go hand-in-hand! Same goes for your back. The more sculpted your back, the nicer your arms AND the slimmer your waistline will appear. Who knew it was all about the optical illusion?? (wink, wink)

Time to graduate from old-school to new-school, and start sculpting that upper body look you’re dreaming of…toned underarms and all.

Here are a few of my fave compound shoulder and back exercises:

Upright Row
Lateral Pulldown (or Pull Ups)
Push Ups (or Bench Press)
T-Bar Row
Shoulder Press

Aim for 3 sets of 12 of each exercise on your upper body days, and don’t work out these muscle groups two days in a row. That day or two of rest in between will help those muscles become even stronger AND more shapely.



Related reading:

Carb Cycling 101
5-Minute Workout for Sculpting Sexy Arms
Sexy Summer Shoulders
Commercial Break Workout: Total Body Blaster
Powell Pack Workout of the Day


  1. Eruca - February 13, 2018

    Hello! I have broad shoulders and large arms (I’m an inverted triangle body type) I was wondering if these exercises were going to make my shoulders bigger.
    Thank you!

    • Team Powell - February 14, 2018

      Hi Eruca: No, they definitely shouldn’t! Go for lighter weight and more reps if you aren’t seeing the results you’d like to see. 🙂

  2. Lisa Sandbo - October 12, 2017

    This is my favorite go-to arm/shoulder workout of all time. I even like to do it on my “rest” days because it makes me feel so good. After reading this blog I started focusing on my shoulders and back and wouldn’t you know I started getting compliments on my nice looking tones arms! Not bad for a 51 year old. 😉

  3. Daniela - October 2, 2017

    I loved this workout!!
    I’ve been doing it for one and a half months now, and the results are amazing!! 💪🏽💪🏽

    • Team Powell - October 3, 2017

      Hi Daniela: Yay! We’re so excited it’s working for you! 🙂

  4. Bev - February 11, 2017

    What can be done if one has gastric bypass?

    Is there anything we can do to help the skin before surgery makes the weight come off too fast? I understand the process of a regular diet followed by these exercises., slow is better. I get the feeling there is nothing I can do if the weight comes off and the skin can’t slowly tighten up. But if I can do anything, to minimize the fallout.

    Do you have any advice on skin creams for tightening skin?


    • Team Powell - February 13, 2017

      Hi Bev: Here’s a post that can offer some ideas: https://heidipowell.net/3485. And there are some skin creams that can help also. Since each person’s skin can react in a different way to weight loss, it’s hard to tell exactly how your skin will react to losing pounds. I’d definitely discuss this with your healthcare team also, and then follow their recommendations. 🙂

  5. Kendal - October 29, 2016

    Definitely gonna bookmark this and give it a try… maybe by spring/summer results will be noticeable!

  6. Nicola - October 28, 2016

    Sigm me up, god love ya

  7. Samantha Thrush - October 28, 2016

    I’m so excited to get back to the gym and give these a try! I’ve been recovering from a back injury for the last 3 months, so exercise has been slow going. I’m ready to get back at it, and these are at the top of my list! Thank you!

  8. Brianna Velasco - October 28, 2016

    I am a mother to three. My oldest just turned 3. My second is 18 months, and my baby girl is 3 months. I am very active – I try to exercise with my kids however I can. The stroller I have is not for jogging, but I do it anyhow. On special occasions my husband is off and I get to enjoy a jog with my daughter the city select I have holds all 3 but it isn’t for jogging and I have fallen, tripped, and face planted over so many rocks that I am afraid to go jogging with my daughter. I love to run. This stroller will allow me to share my story of getting my body back after 3 back to back kids and I would be sure to give it to someone once we outgrow it too. This would be a dream come true and I could enjoy these special moments with my daughter and kids without the fear of someone getting hurt. Here in AZ, the mountains get rocky and the roads where I live off Carefree hwy are dirt. This would change my life! Thank you Heidi for being so kind and giving.

  9. Jaime Preston - October 28, 2016

    I often wonder if my arms will ever tighten up thanks for the advice I hope I can be successful at some point with getting everything tightened and toned!

  10. Kelli Atwood - October 28, 2016

    This is my problem area. So I appreciated this post.
    ( Also, it’s my entry to help win your orbit for my friend Heidi ?…as a mom I’d 5 myself, I know how much I appreciated my Orbit…sadly my babies are growing up too quickly, so I live to see a mommy pay-it-forward)

  11. Andrea Bindewald - October 28, 2016

    Awesome! I will have to start this! #nomoreflabbyarms

  12. Kaitlyn Black - October 28, 2016

    Yes! Okay so yes I am commenting because of the stroller giveaway but I read this blog entry a couple of weeks ago and I was screaming with you! Because I did this lol! But I started focusing on my shoulders (and by biceps) a little more, and did more cardio and…I HAD NEVER HAD NICER/SEXIER ARMS IN MY LIFE. And of course putting the right foods into your body ;).

  13. Holly Steinke - October 28, 2016

    This blog really helped me with the issue of arm flab! You’re totally right. We are way too hard on ourselves, and approach the issue with the wrong idea (ie. no spot fat reduction!)

  14. Whitney Ungaro - October 28, 2016

    This was such a helpful post

  15. Melissa Herzog - October 28, 2016

    Thank you for posting this! I have been focusing so much on legs lately that I’ve totally neglected my arms! After doing these exercises for a couple weeks my arms already look so much better! What a difference strong shoulders can make in your physique!

  16. Kristin St. Laurent - October 8, 2016

    Hi, Heidi. You mentioned what you eat, as well. Any pointers, please? Thank you!

  17. Renea - October 5, 2016

    Please advise! I have been going to the gym for a year now. I am 48 years old and every time I work my upper body I suffer for a week with trap and rhomboid trigger points. How can I fix this. It’s horrible and I dread doing upper body because of this. Thank you in advance.

    • Team Powell - October 5, 2016

      Hi Renea: Have you talked with your healthcare team about this? If not, I’d see what they think is the problem and go from there. I hope it gets better! 🙂

  18. Krystal - October 4, 2016

    What advice do you have as far as working out with auto immune diseases? My whole life has turned upside down and I have celiac disease and hypothyroidism. I have no energy and feel bad all the time. I was told not to do cardio and to lift weights. I’m at a loss because I can’t lose weight. I feel stuck. Any advice please. Thank you and God bless

    • Team Powell - October 5, 2016

      Hi Krystal: It’s always best to follow your healthcare team’s recommendations as far as working out, but a huge part of weight loss is nutrition, and you can check out the nutrition part of Chris and Heidi’s carb cycling program here: https://heidipowell.net/2713. It’s awesome, and it works! 🙂

  19. Brandi - October 4, 2016

    My husband read this and just said sorry to me for all those heavy arm days!! ? I hate my arms and work them out so much, and they just get bigger and fatter! Where have you been all my life!

  20. lish - October 4, 2016

    would like to know your thoughts on breast implant disease – it;s a topic most women know nothing about.

  21. Cindy - October 4, 2016

    I cant afford a gym membership, what exercise can i do at home that will help get rid of these bat wings….

    • Team Powell - October 4, 2016

      Hi Cindy: If you have minimal equipment, all of these exercises can be done at home! And here’s another arm workout that can be done at home too: https://heidipowell.net/6054. 🙂

    • Helen - October 4, 2016

      Order the Body Gym system with resistance band from QVC. You will ❤️It for what you’re looking to do . Cost me $39 last year. Read the reviews. It comes with a great instructional video, but you can always You Tube a segment of Marie Osmond on the show giving great instructional video as well.

  22. Cece - October 4, 2016

    I’d also like to know- should I now sub these moves for days I would’ve done triceps, essentially no longer have tri days?

    • Team Powell - October 4, 2016

      Hi Cece: These exercises work your arms, shoulders, and back, so they can replace any tri moves you may have been doing, plus you get the bonus of working other muscles in addition to your tris. 🙂

  23. Misty - October 4, 2016

    So happy to see this!! I already do these so I’m glad to know I’m on the right track, or will be. After months of being out due to medical issues I will happily walk back into the gym TODAY!

  24. Marie - October 4, 2016

    Great advice! Now I need to know what shoes those are! I love them! Can you please tell me what brand?

    • Team Powell - October 4, 2016

      Hi Marie: They’re the Reebok FuryLites: http://shrsl.com/?~bv68 🙂

    • Bev Stultz - October 4, 2016

      I also love the shoes. Went to the site, but can’t find them. Could you please tell the name of the shoe? I realize Reebok FuryLites, but they are not there, other FuryLites are, but not these.
      Thank You,

    • Team Powell - October 4, 2016

      Hi Bev: This particular color combo might’ve been discontinued. 🙁

  25. Veronica - October 4, 2016

    Hi Heidi!
    What’s the best way hint to eat or drink before a work out? Recently I started an int nose workout called Orangetheory and I’ve been burning around 600 calories but when I leave I’m starving! What should I eat or drink to get ready?
    Ps thanks for the arm advice!!

  26. Patricia - October 4, 2016

    Don’t know how to do them.

    • Donna - October 4, 2016

      Click on the exercise names in the article and it will take you to a video demo of each exercise

  27. Angie - October 4, 2016

    So will this help people who actually have excess skin from previously losing a lot of weight?

    • Team Powell - October 4, 2016

      Hi Angie: How each person’s skin reacts to weight loss can be very different, but working and building those muscles underneath the skin can definitely help! 🙂

  28. Jeanice - October 3, 2016

    Awesome! Love you, Heidi!

  29. Megan - October 3, 2016

    Oh thank God for you Heidi! I dislike strongly tricep extensions! ? cant wait to focus more on back and shoulders. Struggle a lot with my back, so ill try these moves more than the lamo biceps and tricep curls! Yay!

  30. Sheila - October 3, 2016

    I don’t have a gym membership. Is it possible to do these upper body exercises at home? If so, how?
    Thanks for your time.

    • Team Powell - October 4, 2016

      Yes! If you have this equipment (which is minimal), you can totally do these at home!

  31. Patty - October 3, 2016

    So are you saying that we should never do bicep curls and tricep extensions? Because I love doing tricep extensions.

    • Shannon - October 3, 2016

      I’m wondering the same. Although I hate triceps extensions so I’d be happy to never do them again haha.

  32. Tracie Radawec - October 3, 2016

    You are so awesome! My daughter is 13 and I got her wkg out we go together! She also swims so I am getting her ready to swim for high school next year at Corona Del sol and I love that you are from AZ! I was wondering when you are free sometime if we could meet up and you can show me some stuff at the gym I am still learning and I want to teach my daughter the right way of training! We live in Tempe and I work for the Kyrene school dist in the preschool at Kyrene De Las Manitas school! I love it! Thank you for being so awesome and I hope to hear from you soon! And I am on Facebook to I am one of your friends Tracie Conway Radawec! Thank you, Tracie 🙂

  33. Marie Hire - October 3, 2016

    Do you have an alternative for the T-bar row? I can do all these at home except that one!

    • Team Powell - October 4, 2016

      Hi Marie: You can substitute a different type of row – using dumbbells – that mimics the same movement without the T-Bar. 🙂

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