This singlet can be worn for athletics & cross country.
There is a newer option but this is still acceptable as uniform for cross country and athletics.
1/2 chest measurements:
K8-37cm, K12-42cm, K14-45cm
W10-40cm, W14-44cm, W18-51cm
S-45cm, M-50cm, L-52cm, XL-58cm, 2XL-60cm, 3XL-66cm, 4XL-70cm