a district court invoke it at screening under § 1915A, see Walker v. Thompson, 288 F.3d 1005, 1010 (7th Cir. 2002). On the merits we also agree with James that he states claims under both the Eighth and Fourteenth Amendments. Our decisions are clear that preventing inmates from exercising for prolonged periods may violate the Eighth Amendment. See, e.g., Turley, 729 F.3d at 652 (explaining that persistent lockdowns resulting in inability to exercise may violate Eighth Amendment if imposed without proportional justification); Delaney v. DeTella, 256 F.3d 679, 683-85 (7th Cir. 2001) (concluding that Stateville officials accused of denying plaintiff all out-of-cell exercise for six months could not rely on defense of qualified immunity); Pearson v. Ramos, 237 F.3d 881, 884 (7th Cir. 2001) (<HOLDING>); Antonelli v. Sheahan, 81 F.3d 1422, 1432 (7th
holding that what constitutes cruel and unusual punishment is a question of law holding that a cruel and unusual punishment claim is not jurisdictional and therefore may not be raised for the first time on appeal holding cruel and unusual punishment complaint not preserved recognizing that denying outofeell exercise for extended periods may constitute cruel and unusual punishment holding the constitutional right to be free from cruel and unusual punishment may be waived