Ref :
Key feature
FINA (International Swimming Federation) approved swimming competition jammers that combine compression, glide and hydrodynamics thanks to AQUARACE technology.
Users reviews
3.38 / 5 55 ratings

Products benefits

AQUARACE technology reduces body drag resistance in water.
Glide performance
Water repellent fabric absorbs virtually no water and guarantees a perfect glide
Muscle support
Excellent muscle compression at the quads and glutes.
The B-FAST JAMMER's component is ultra thin and lightweight 155 g/m2


From EU size 36 to 46
Main fabric : 53.0% Polyamide, Main fabric : 47.0% Elasthane Lining : 77.0% Polyamide, Lining : 23.0% Elasthane
Designed to
competitive swimmers. Developed with Fabien Gilot, Olympic Champion and NABAIJI technical partner.
2 years


Storage Tips
Store the swim shorts in a dry place.


JAMMER – length 44 cm The Jammer provides great muscle compression for the quads and glutes, resulting in the perfect fit.
AQUARACE material is ultra-thin and lightweight thanks to high percentage of elastane, whilst remaining highly tear resistant. Moreover its thinness and water repellency enable ultra quick drying after swimming. In fact the water repellent fabric absorbs virtually no water and actually blocks it on the outer surface, creating micro bubbles that assist with buoyancy
The B-FAST Jammer is FINA (International Swimming Federation) approved competition swimwear.
The swimsuits and jammers benefiting from AQUARACE technology are designed for competitive swimmers to enhance performance by incorporating superior hydrodynamics, increased buoyancy as well as fatigue reduction during physical exercise.
Component provides good compression with its high elastane content and very good springback. The position of the red reinforcement stripes provides more compression at belt and leg level. Thanks to a scientific cut and a muscle compressing material, the drag coefficient of the water is increased and the blood flow optimises energy expenditure, which helps regulate fatigue
Score to compare the environmental impact of products
The environmental impact of the product is calculated over its entire life cycle and with different indicators. An overall ABCDE rating is performed to help you easily identify the products with the best environmental performance by comparing the same type of products with each other (t-shirts, trousers, backpacks). Decathlon is a committed stakeholder in this environmental labelling approach. Website: sustainability.decathlon.com Explanatory video: https://youtu.be/8t63KkRwn_8

Users reviews

3.38 / 5 55 ratings
31 users recommended this product

At Decathlon, reviews are reliable.

  • Man
    20-29 years old
    03 September 2018
    Use since 2 to 8 weeks
    That review has been deposited on this product version
    Good item

    Little bit tighter and less stretchy than expected but great in the water

  • Man
    20-29 years old
    03 September 2019
    Use since 1 week or less
    That review has been deposited on this product version
    Too Tight

    I'm a size 33-34 for all my pants however bought a size UK36 and it was extremely tight in all the places.

    Will not recommend for slighly curvier men.

    Brand response :

    Hi Jubir Farhan,

    Thank you for leaving a review on our product, FINA 900 FAST MEN'S COMPETITION JAMMER SHORTS - BLACK ORANGE (8387993).

    I apologize if the product did not match up to your expectations. Just to share with you, this swim jammers for men is designed for body-fit, which should feel like a second skin while supporting your muscles. It is meant for competition use and not for training, which is the reason why it has a tighter fit as compared to the usual swim jammers.

    I would like to recommend you another pair of swimming jammers which would be better suited for your needs. This swim jammers has a body hugging design which is more comfortable as compared to the competition jammers. It is also able to withstand up to 200 hours in chlorine water while maintaining muscle support. This model also comes in plenty more sizes as compared to the competition jammers. For your reference, it can be found on our website here.

    If you need any further advice or assistance regarding our products, please feel free to drop by Joo Koon Store or reply to my email.

    Once again, thanks for your review and hope to see you again at Decathlon soon!


    Swimming Sports Leader
    Decathlon Singapore | Joo Koon Store

  • 24 July 2019
    That review has been deposited on this product version
    Material ist unelastisch, steif und unbrauchbar

    Ich habe die Hose in Gr. M +XS für die Schwimmwettkämpfe meiner Jungs (10+14 Jahre) bestellt. Beide sind sehr schlank.
    Das Material ist unelastisch und steif. Der 14-jährige hatte keine Chance in die Hose rein zukommen. Der 10-jährige hat dann die Hose, die für seinen Bruder bestimmt war, angezogen.
    Es war eine einzige Katastrophe. Wie soll ein Mann in diese Herrenhose passen?????.... wenn es einem Kind nicht gelingt???

    Brand response :

    Hallo Gerlind,

    vielen Dank, dass du dir die Zeit genommen hast, das Produkt FINA 900 Fast Men's Competition zu bewerten.
    Schade, dass die Passform nicht zu deiner Zufriedenheit ist.

    Es ist richtig, dass das Material sehr steif und unelastisch ist. Dies bringt eine hohe Muskelkompression in den Oberschenkeln und die Oberfläche verhilft zu mehr Hydrodynamik. Wir arbeiten bereits an der Anpassung der Größen, da wir das Feedback bereits öfter bekommen haben. Wir stehen im ständigen Austausch mit unseren Eigenmarken um unsere Produkte stetig zu verbessern.

    Mit deinem Kundenkonto kannst du deine Produkte innerhalb von 30 Tagen auch nach Benutzung in einer Filiale oder online umtauschen. Solltest du dazu Fragen haben, kannst du dich gern unter service[at]decathlon.de noch einmal melden.

    Ich hoffe ich konnte dir weiterhelfen.
    Mit sportlichen Grüßen

    Gerlind find this answer useful