The best training tool you're not using: a jump rope. “It may seem a little juvenile until you think of all the hot-bodied boxing pros who jump rope every single day,” says Landon LaRue, a CrossFit level-one trainer at Reebok CrossFit LAB in L.A. Not only is it inexpensive, portable, and easy to use almost anywhere, you’ll burn about 200 calories in 20 minutes and boost your cardiovascular health while toning, he adds.
^ Jump up to: a b c Aldridge, Robert W.; Story, Alistair; Hwang, Stephen W.; Nordentoft, Merete; Luchenski, Serena A.; Hartwell, Greg; Tweed, Emily J.; Lewer, Dan; Vittal Katikireddi, Srinivasa (2017-11-10). "Morbidity and mortality in homeless individuals, prisoners, sex workers, and individuals with substance use disorders in high-income countries: a systematic review and meta-analysis". Lancet. 391 (10117): 241–250. doi:10.1016/S0140-6736(17)31869-X. ISSN 1474-547X. PMC 5803132. PMID 29137869. All-cause standardised mortality ratios were significantly increased in 91 (99%) of 92 extracted datapoints and were 11·86 (95% CI 10·42–13·30; I2=94·1%) in female individuals