HIIT stands for high-intensity interval training. “This refers to tough quick, intense bursts of exercise, followed by short recovery periods. This type of training gets and keeps your heart rate up,” explains Laferrara, while also (typically) decreasing the overall amount of time you spend training. This workout is great for burning fat because the intense intervals help kick-start the process known as excess post-exercise oxygen consumption (AKA the “afterburn effect”), which helps you burn more calories even after you stop working out as your body has to work harder and take in more oxygen to return to its resting state.
In her hilarious, naked, and explicitly honest anecdote, she described her aversion to most fitness regimens ("I can't run because I piss myself . . . and fart at the same time"), her DVD workout — "Charlotte's 3-Minute Belly Blitz" — and her complete surprise at the intensity of the routine ("THAT'S the f*cking WARMUP?"). To be honest, most of us have been there, so this is pretty damn relatable.
It’s not an exact science, but when you hear the term plyometric, you can go ahead and think jumping and breathlessness. Examples would include squat jumps, box jumps, broad jumps, and burpees. One of the main purposes of these explosive exercises is increasing power, says Laferrera. Having more power means you can recruit muscle fiber faster and more efficiently, which pays off when you’re moving heavy objects or working on sprinting drills in the gym, adds Lefkowith. Plus, because these moves get your heart rate up, they’re big calorie-burners. Here are seven plyometric moves you can do at home.
Thus, little is known about the effects of monitored vigorous exercise in elderly people. While significant benefits for basic motor tasks (such as balance and gait) can be achieved through different kinds of physical activity (i.e., stretching exercises, treadmill, Pilates, and strength and balance training), no conclusive relationship has been proven between its intensity and such improvements. Recently, Pau et al.  reported that spatiotemporal gait parameters and sit-to-stand performance significantly improve through vigorous (but not light) exercises, thus suggesting that higher levels of intensity might be more suitable in generally improving static and dynamic daily motor tasks.