"Bursitis and tendinitis are both common conditions that cause swelling around muscles and bones. They occur most often in the shoulder, elbow, wrist, hip, knee, or ankle.
A bursa is a small, fluid-filled sac that acts as a cushion between a bone and other moving body parts such as muscles, tendons, or skin. Bursae are found throughout the body. Bursitis occurs when a bursa becomes swollen.
A tendon is a flexible band of tissue that connects muscles to bones. Tendons can be small, like those found in the hand or ankle, or large, like the Achilles tendon in the heel. Tendons help create movement by making the muscles push or pull the bones in different ways. Tendinitis is the severe swelling of a tendon." as retrieved from:
The National Institute Arthritis and Musculoskeletal and Skin Diseases
High Intensity Interval Training (HIIT) is an exercise modality where exercise is performed at a high intensity or all out effort for a period of time (normally 10-30seconds) followed by a period of lesser intensity training. These periods are referred to as intervals.
An example of HIIT Training is Tabata.
Other intensity based exercise modalities commonly used are:
An exercise modality is simply an exercise style/approach. For example if you hear the term high intensity interval training (HIIT), it is referring to an exercise modality where you have periods of high intensity followed by periods of lower intensity.
When you hear the term cardio it is usually describing an activity where you're sweating and exercising at a moderate intensity for a prolonged period of time. Activities normally referred to as cardio bouts of exercise performed on an elliptical machine, stair stepper, climber, treadmill, or rowing machine.
Cardio comes from the word cardiovascular meaning heart and vascular (veins) system.