Speedo Junior Fastskin Endurance+ Max Kneesuit Size Guide

Our World Aquatics-approved Fastskin Junior Endurance®+ Max Openback Kneeskin emulates the style lines of our popular LZR Valor suit, so young swimmers can look and feel like their swim heroes as they step up to the blocks. Designed specifically for young swimmers, the suit features high-energy colours. Its open-back style and 4-way stretch fabric ensure comfort and freedom of movement, allowing junior athletes to focus on their race. Built to last, it’s chlorine resistant, quick-drying, and designed to withstand everything their race day swim sessions throw at it.

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Body Measurement Points
Girls body measurement guide showing chest, waist and hip measurement points
How to Measure

To find the correct size, use a soft measuring tape and take all measurements directly against your child’s skin. Always use body measurements — age is shown as a guide only, as children develop at different rates.

  • A
    Chest Measure around the fullest part of the chest, keeping the tape parallel to the floor. This is the primary sizing measurement for girls.
  • B
    Waist Measure around the natural waistline at the narrowest point of the torso.
  • C
    Hips Measure around the fullest part of the hips and seat, keeping the tape parallel to the floor.

Note: Ages shown in the sizing table are a guide only. Always measure and use body measurements to select the correct size.

Sizing Table — Speedo Girls’ Fastskin Junior Endurance®+ Max Kneeskin
Size 24 Size 26 Size 28 Size 30 Size 32 Size 34
Age (guide only) 5–6 yrs 7–8 yrs 9–10 yrs 11–12 yrs 13–14 yrs 15–16 yrs
Body Measurements
Chest cm 61 66.5 72 77.5 84 90.5
Waist cm 56 59 62 65 69 73
Hips cm 64 70 76 84 90 96

All measurements are body measurements, not garment measurements. Speedo racing suits are designed to fit snugly — if between sizes, we recommend sizing up. Contact Allens if you need guidance.

Fit Notes — Speedo Girls’ Fastskin Junior Endurance®+ Max Kneeskin
  • Size based on chest measurement as the primary guide, with waist and hip measurements used to confirm fit. For girls, the chest is the most reliable starting point for kneeskin sizing.
  • Fastskin racing suits are designed to fit tighter than a training suit. Some initial resistance when putting on is normal and is not a sign that the suit is too small.
  • The open back should sit flat across the shoulders with the straps lying flush against the skin. There should be no gaping or twisting at the back panel.
  • Constructed from Endurance+ Max chlorine-resistant fabric — rinse in cold fresh water after every session and allow to dry naturally away from direct sunlight.
  • Unsure? Contact our team or call +44 1827 330600.
Frequently Asked Questions — Speedo Girls’ Fastskin Junior Endurance®+ Max Kneeskin

Measure the chest, waist, and hips in centimetres and match to the size table above. Use chest as the primary measurement. Speedo racing suits are designed to fit snugly, so some compression is expected. If measurements fall between sizes, size up for comfort, particularly for younger swimmers still growing.

Yes. The Fastskin Junior Endurance®+ Max Openback Kneeskin is World Aquatics approved and legal for use in sanctioned competitions. Always check with your club or event organisers to confirm the specific approval requirements for your level of competition.

The Fastskin Junior Endurance®+ is a racing kneeskin, not a training suit. It is designed for competition with a closer, more compressive fit, low-profile flat lock seams to minimise drag, and an open-back cut that mirrors the adult LZR Valor style. It is made from chlorine-resistant Endurance+ Max fabric so it can handle regular training sessions, but its primary purpose is race performance.

The size range covers UK ages 5–6 years (size 24) through to 15–16 years (size 34). Always size based on measurements rather than age alone, as fit can vary considerably between swimmers of the same age.

Yes. Racing kneeskins are designed to fit considerably tighter than training suits. Some resistance when pulling the suit on is entirely normal and does not mean the suit is too small. Once on, the suit should feel compressive but should not restrict breathing or circulation. If the swimmer is uncomfortable in the water, consider sizing up.

Roll the suit from the legs upward, working it gradually up the body rather than pulling from the top. Take care around the seams and fabric panels — do not pull sharply or use fingernails, as this can damage the material. Wetting the suit or the skin slightly can help ease it on. Allow at least 10–15 minutes to put the suit on before racing.

Rinse in cold fresh water immediately after use to remove chlorine and salt. Do not wring, tumble dry, or expose to direct sunlight for extended periods. Lay flat or hang to dry naturally. Avoid sitting on rough pool surrounds while wearing the suit, as this can cause abrasion to the fabric panels.