Does High Intensity Interval Training Work Aug 21, 2017. So if I had an older person who came to me and said 'I want to do high-intensity interval training,' I would start them out and work them up to it.”. High-intensity. since 2012, does low-intensity training by walking a mile in the pool four days a week. Elvey also takes Active Choose two dumb-bells that you can hold comfortably -…