Fly-By 3'' Running Shorts
Product code: T128983S
About this style
Experience next-level comfort with these Fly-By 3'' running shorts from Under Armour. They're cut in a regular fit with split sides for unrestricted movement during your workout, whether you're hitting the gym, track, trail running, or going for a jog. The elasticated waistband features an internal drawcord for a secure, adjustable fit. Made from lightweight, breathable fabric, they wick away moisture and dry quickly to keep you feeling fresh during athletic training sessions, even when things get sweaty. Practical details include an invisible zip pocket for your valuables and mesh panels for enhanced ventilation, making them ideal performance activewear and sport apparel for any active pursuit. These comfortable athletic bottoms are perfect fitness gear for the dedicated athlete seeking new levels of comfort and functionality.
Curated By
Details & care
Fit and style
•
Regular fit
•
Elasticated waist
•
Mid rise
Composition
Body - 100% polyester
Care
Machine wash according to instructions on care label
Delivery, collection & returns
Delivery
Standard
UK Standard Delivery is available for £3.99 or free on orders over £75 (excluding furniture).
Returns
UK returns
Free. Returns can only be arranged via postal options. Exclusions apply Full delivery and collection information Our returns policy
Exclusions apply
Full delivery and collection informationOur returns policyAbout Under Armour
Train at your best, no matter the weather, with Under Armour's innovative clothing, footwear and accessory designs.
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Reviews (144)
Bring back the pockets!
Originally posted on Under Armour
Yes, I recommend this
Love these shorts. They have consistently been my go to for running. However, I have to be able to stash a phone in a pocket. They no longer have the pockets that are big enough to carry a phone. Have had to move on to another brand.
Helpful?
Replied
26 May 2026
Hey there! Your go-to running short for years and we go and take away the pockets. We hear you and we're sorry about that. The Fly-By redesign went in a more minimal direction but we know that doesn't work for everyone who needs to carry a phone on a run. The UA Launch shorts might be worth a look as they offer a larger side pocket built for your phone. Keep an eye out for an email from us!
10/10 purchase
Originally posted on Under Armour
Yes, I recommend this
This is my 3rd pair of these shorts and they're super reliable and comfortable for everyday wear. Love the array of colors and they fit true to size. Great for being inside lounging and outdoor yard work or walking around
Helpful?
Great for summer
Originally posted on Under Armour
Yes, I recommend this
Great for lounging around the house or for cardio. True to size and very comfortable
Helpful?
Love these shorts
Originally posted on Under Armour
Yes, I recommend this
I ran a 5k in these shorts, and they were very comfortable and light weight. They also dry verify quickly. I am a huge fan and plan on purchasing more when the time comes.
Helpful?
Great workout shorts
Originally posted on Under Armour
Yes, I recommend this
My high school daughter uses these shorts for all her workouts and loves them. I had to order more because she doesnt want any other shorts now. Great product.
Helpful?
This product has a good fit
Originally posted on Under Armour
Yes, I recommend this
This product has a good fit and lightweight. Perfect for track and field events.
Helpful?
Perfect fit
Originally posted on Under Armour
Yes, I recommend this
True to size great for running.
Helpful?
Comfy
Originally posted on Under Armour
Yes, I recommend this
I love the neon look. And how it flows.
Helpful?
Shorts
Originally posted on Under Armour
Yes, I recommend this
Fit great true to size great for all activities
Helpful?
Comfortable
Originally posted on Under Armour
Yes, I recommend this
Comfortable fit and easy to run in.
Helpful?
To small
Originally posted on Under Armour
Yes, I recommend this
I ordered the same size as the other 2 pairs I got but these ones fit different they are smaller. I love the color tho.
Helpful?
Replied
21 March 2026
Hi! We're so glad to hear that you love the color of this style. But we're bummed that the sizing wasn't consistent, that's definitely frustrating! I'll be reaching out via email shortly to get some additional details and help you with this.
I used to love these shorts
Originally posted on Under Armour
No, I don't recommend this
This style used to be my favorite shorts, but the fit was different. Now, they fit weird and are not flattering at all. They're very loose fitting and frumpy.
Helpful?
Replied
20 March 2026
Hi, Jamie! Not loose and frumpy! That's definitely not how we want our shorts to make you look and we're sorry that's the vibe. We want our gear to make you feel next-level and we'd love another shot at finding you something that does. Please look for an email from me with more details.
Excellent track shorts
Originally posted on Under Armour
Yes, I recommend this
Granddaughter loves running in these shorts. (I wish they were a little longer)
Helpful?
Best workout shorts
Originally posted on Under Armour
Yes, I recommend this
My go to shorts for the last 5 years. Love the brief coverage and it's comfortable and light perfect for any workout. No other brands or model compares
Helpful?
This product is excellent!
Originally posted on Under Armour
Yes, I recommend this
The product is very comfortable, it fits me very well. I can wear this when I play tennis or I am using the treadmill in the gym, because it can dry out very quickly so that I will not feel uncomfortable or wet all the time. I like this product very much. Also, the color is great. I think y'all should buy it.
Helpful?
Super Cute and Comfortable!
Originally posted on Under Armour
These shorts are perfect! I bought them becuaseI have another pair of underarmour shorts that have lasted me YEARS. They are super cute and incredibly comfortable. They did feel a little small even though I got a Large but they still fit comfortably and I'm also 5'9 and they aren't too short.
Helpful?
So comfortable
Originally posted on Under Armour
Yes, I recommend this
Great fit, light fabric. Bought in several colors.
Helpful?
Best shorts
Originally posted on Under Armour
Yes, I recommend this
From training to everyday errands these are a win
Helpful?
Ride up a little bit!
Originally posted on Under Armour
Yes, I recommend this
I may have ordered a size too big. Not sure if that's the issue. Overall a good pair of shorts.
Helpful?
This product was a gift, but my sister loves it!
Originally posted on Under Armour
Yes, I recommend this
These shorts were a Christmas gift for my sister. I think I brought every Jasper Blue item available. She loved the color!
Helpful?
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