What counts as vigorous exercise?

Vigorous intensity activities, the kind that makes you breathless and red in the face, are defined as activities that burn more than 6 METs.

MET is the ratio of a person's working metabolic rate relative to their resting metabolic rate. One MET is the energy it takes to sit quietly. One MET is equivalent to a caloric consumption of 1kcal/kg/hour.

Here's a list of vigorous activities (more than 6 METS):

• Running
• Hiking / walking briskly up a hill
• Jogging at 6 mph (10km/h)
• Bicycling fast (14–16 mph)
• Swimming fast (butterfly, freestyle)
• Shoveling
• Carrying heavy loads (> 20kg)
• Competitive sports (eg Basketball, Soccer, Hockey games)
• Tennis—singles

How can I change up Moderate intensity activities into Vigorous exercise?
Vigorous exercise linked to living longer

Why is this important?

Because research showed that vigorous activities are not the same as moderate activities and people who do vigorous activities live longer.

What are the recommendations?
The Australian Government's "Physical Activity Guidelines" are much like the CDC's:

• Doing any physical activity is better than doing none. If you currently do no physical activity, start by doing some, and gradually build up to the recommended amount.
• Be active on most, preferably all, days every week.
• Accumulate 150 to 300 minutes (2 ½ to 5 hours) of moderate intensity physical activity or 75 to 150 minutes (1 ¼ to 2 ½ hours) of vigorous intensity physical activity, or an equivalent combination of both moderate and vigorous activities, each week.
• Do muscle strengthening activities on at least 2 days each week.

(from: http://www.health.gov.au/internet/main/publishing.nsf/Content/health-pubhlth-strateg-phys-act-guidelines, last accessed 7 June 2015)

Read more: 

Vigorous exercise linked to living longer

Harvard's guidelines on activity for the prevention of obesity

WHO's guidelines on physical activity