People with knee injuries or tendinitis should not do plyometric box exercises. It's great. . . . You see people talking and working out together whom you normally wouldn't see with one another. Seasoned lifters will not add extra bulk, but the class can help maintain tone. If a weight feels too heavy, switch to a lighter one and increase only when you're ready.
Some beginners just use a bar.
This is martial arts aerobicized. Kwando aficionados perform combinations of kicks and punches at varying speeds to loud, rhythmic tunes. Repeated high kicks make for impressive abdominal and upper leg definition. Kwando could aggravate existing lower back problems. This class uses minitrampolines and music to get hearts racing.