Very loose. Thin fabric. Looks and feels cheaper than the pictures suggest. If you want a premium workout shirt, spring for the&nbsp;<a data-hook="product-link-linked" class="a-link-normal" href="/prAna-Men-s-Neo/dp/B004QQ5ICO/ref=cm_cr_arp_d_rvw_txt?ie=UTF8">prAna Men's Neo</a>.