Head to head
Nike Brasilia 9.5 Small 41L vs Under Armour Undeniable 5.0 Medium 58L (2026)
Nike Brasilia 9.5 Small 41L vs Under Armour Undeniable 5.0 Medium 58L compared: capacity, shoe compartment, weather resistance, and which duffel you should buy.
#1 in our rankings · Best overall
Nike Brasilia 9.5 Training Duffel Bag Small 41L
Best for: Most gym goers, and anyone who wants one duffel for training, swimming, and short trips.
#2 in our rankings · Best medium duffel
Under Armour Undeniable 5.0 Duffle Medium 58L
Best for: Longer sessions, two-a-day training, and anyone whose kit never quite fits in a 41 litre bag.
Our recommendation
Buy the Nike Brasilia 9.5 Small 41L if you want one duffel for the daily gym run: a ventilated shoe compartment, a 41 litre main space, and a low cost. Buy the Under Armour Undeniable 5.0 Medium 58L if your kit never fits in 41 litres, or you want a water-resistant finish and five compartments. Both ventilate their shoe pockets, so the choice is size and weather resistance against cost and compactness.
Capacity: 41 litres against 58 litres
The Nike holds a session: shoes, a change of clothes, a towel, and a bottle. The Under Armour holds a long session: the same kit plus a belt, a shaker, and a second set of clothes. The extra 17 litres is the whole difference for most buyers, and it should be matched to the real load, not the imagined one.
Weather resistance
The Nike shell is light polyester that wipes clean but is not rated against rain. The Under Armour UA Storm finish sheds rain and sweat, and the abrasion-resistant bottom takes rough floors. For a dry car park the difference is small, but for a rainy walk it is the reason to spend more.
What they share
Both are honest gym duffels with ventilated shoe compartments, both are black, and both come from brands with a long track record in gym kit. Neither has a laptop sleeve, and neither is a backpack, so both buyers should look at the Hustle 5.0 if they walk to the gym and want a laptop sleeve.
Choose Nike Brasilia 9.5 Training Duffel Bag Small 41L if…
- You want one duffel for the daily gym run
- You want the lowest cost
- You want a compact bag that fits a small locker
Choose Under Armour Undeniable 5.0 Duffle Medium 58L if…
- Your kit never fits in 41 litres
- You want a water-resistant finish
- You want five compartments for organisation
Spec-by-spec comparison
| Spec | Nike Brasilia 9.5 Training Duffel Bag Small 41L | Under Armour Undeniable 5.0 Duffle Medium 58L |
|---|---|---|
| Price tier | Budget | Mid-range |
| Capacity | 41 litres | 58 litres |
| Dimensions | 50 x 28 x 28 cm | 24.6 x 12.1 x 11.4 inches |
| Material | 100% polyester | 100% polyester |
| Shoe compartment | Ventilated, separate | - |
| Colour | Black/Black/White | - |
| Finish | - | UA Storm water-resistant |
| Compartments | - | 5, including ventilated shoe pocket |
| Best for | Most gym goers, and anyone who wants one duffel for training, swimming, and short trips. | Longer sessions, two-a-day training, and anyone whose kit never quite fits in a 41 litre bag. |
| Skip if | You carry a lot of bulky kit, or you want a backpack for cycling and walking to the gym. | You want a compact bag for a quick session, or you prefer backpack carry. |
Strengths and limitations
Nike Brasilia 9.5 Training Duffel Bag Small 41L
Strengths
- The ventilated shoe compartment keeps trainers away from clean clothes, which is the single most useful feature in a gym bag.
- At 41 litres it holds shoes, a change of clothes, a towel, and a water bottle without turning into a travel bag.
- The 100 percent polyester shell is light, wipes clean, and has survived years of daily use in gyms everywhere.
Limitations
- It has no padded laptop sleeve, so it is a gym bag first and a work bag second.
- The single shoulder strap carries the whole load on one side, which gets tiring on a long walk.
- The black colour shows chalk dust and lint, and it needs a wipe after heavy sessions.
Under Armour Undeniable 5.0 Duffle Medium 58L
Strengths
- The 58 litre main compartment swallows shoes, clothes, a towel, and a shaker without a fight, and the bag still fits in a standard locker row.
- The UA Storm finish sheds rain and sweat, and the abrasion-resistant bottom takes being dropped on rough floors.
- The ventilated shoe pocket and the five compartments keep kit organised instead of piled in one big space.
Limitations
- Fully packed it is a heavy one-shoulder carry, and the padded strap only helps so far.
- At 58 litres it is bigger than a quick session needs, and it looks oversized on a short gym run.
- The black fabric shows chalk and dust, and the bag needs a wipe after heavy use.
How they fit the wider field
- Nike Brasilia 9.5 Training Duffel Bag Small 41L: ranked #1 (Best overall) in The Best Gym Bags. Read the full Nike Brasilia 9.5 Training Duffel Bag Small 41L review.
- Under Armour Undeniable 5.0 Duffle Medium 58L: ranked #2 (Best medium duffel) in The Best Gym Bags. Read the full Under Armour Undeniable 5.0 Duffle Medium 58L review.
Neither one quite right? The full rankings cover 10 picks matched to different buyers.
Made your call?
Questions, answered
Which one is better for a home gym?
The Nike, for most home gyms, because it covers a session at the lowest cost and the compact size suits a home locker or a bench. The Under Armour is better only if the load is genuinely bigger, which usually means two-a-day training or a session plus a swim.
Do both have a shoe compartment?
Yes, and both ventilate it, which is the key point. The Nike compartment sits apart from the main space, and so does the Under Armour pocket. Either bag keeps trainers away from clean clothes, so the choice is size, not shoe separation.
Which one lasts longer?
The Under Armour, on balance, because the UA Storm finish and the abrasion-resistant bottom are built for rough use. The Nike lasts well for a daily session, but the lighter shell will show wear sooner under heavy use. Both last years when used for their intended job and stored dry.