Aerobic exercise involves regular body part (e.g., arms or legs) movements that increase workload on the cardiovascular system. It is convenient and useful to think of the intensity of aerobic exercises in metabolic equivalents, or METs. One MET represents the amount of energy used at rest, and two METs is twice that much energy expenditure per unit of time, and so on. Aerobic exercise is widely recommended in contemporary guidelines. However, guidelines also indicate that exercise regimens are contraindicated in patients with unstable cardiovascular conditions, including but not limited to uncontrolled severe hypertension (BP ≥ 180/110 mm Hg). Conditions under which stress testing should be performed before initiation of an exercise regimen have been described.37
A good way to begin is to write down a weekly exercise plan, including when you will exercise each day, and continue to do so every week for three months if you are serious about sticking with exercise but concerned about your motivation. Write down what day(s) of the week, what time of day, minutes of activity, and the activity that you'll do when setting your plan. Be as specific and realistic as possible, and remember that it's not how much you do when you start that counts but that you simply do something. Getting started is usually the hardest part. You can always add more later on.
Improper digestion can lead to gastrointestinal discomfort, bloating, constipation, diarrhea, and even colon cancer. Therefore, it is very important that you keep your digestive system healthy. Apart from maintaining good food habits and drinking water, you should also walk to improve digestion. Walking after meals is great. It helps you reduce weight and also supports your digestive system (11) (12).

Dr. Tannenberg offers another tip for incorporating intervals into your workout: “Create a new playlist with upbeat songs followed by slower songs. Alternate the songs on your playlist. When you are walking and hear a faster song, you increase your pace. When the slower song comes on, you slow down the pace a bit. This is an easy way to make your normal morning walk an interval workout.”
Your body’s immune system should function properly at all times to prevent infections, diseases, and death. Walking is a great way to boost your immunity. Walking at least 30 minutes a day can help bolster the activities of the immune cells, namely, the B-cells, T-cells, and the natural killer cells (13). It helps release the WBCs at a faster rate, thereby allowing your body to heal quickly (14).
Aerobic exercise (also known as cardio) is physical exercise of low to high intensity that depends primarily on the aerobic energy-generating process.[1] "Aerobic" means "relating to, involving, or requiring free oxygen",[2] and refers to the use of oxygen to adequately meet energy demands during exercise via aerobic metabolism.[3] Generally, light-to-moderate intensity activities that are sufficiently supported by aerobic metabolism can be performed for extended periods of time.[1] What is generally called aerobic exercise might be better termed "solely aerobic", because it is designed to be low-intensity enough so that all carbohydrates are aerobically turned into energy.


To start losing weight, you need to burn about 600 calories a day more than you’re eating and drinking, and for that, you might have to up your speed. You can burn off twice as many calories by walking at 4 miles an hour (6.5 kilometres per hour) than you can at half that speed. Walking also increases muscle mass and tone. In short, the more muscle you have, the faster your metabolism, so the more calories you burn off.
Use the 1-to-10 scale of perceived rate of exertion to measure endurance. Think of 1 as watching TV; 10 is gasping for air (you can't go any further). Daily walks, for example, are 5 or even 6-6.5 sometimes. Twice a week, crank it up to 7, 8, or 9 on a steep hill for a few minutes. Now you're burning serious calories and building real aerobic fitness through interval training.
“Cardiovascular disease remains the number one cause of death in America,” says Dan G. Tripps, PhD, the chief operating officer and director of exercise science for Speck Health, a lifestyle medicine practice in Seattle. “Associated with physical inactivity, high cholesterol, high blood pressure, and smoking, cardiovascular disease accounts for approximately a quarter of all U.S. deaths. (3) 

So where do you start? “The right place to start with walking intervals will depend on your current fitness level, but here's a treadmill interval template to test out and see what adjustments you need to make,” says Spraul. “Start by walking for 5 minutes at a comfortable speed with no incline to get warmed up. Once you're done there, increase the incline to 5 percent for 3 minutes (no need to increase the speed when you're first starting out). After those 3 minutes are up, return to 0 incline for 1 minute of rest, while keeping the same speed. Repeat this for 3-5 rounds, depending on how you're feeling. Then you can adjust as needed: To add difficulty, you can increase the ‘work’ time that you spend on the incline, decrease the time you spend ‘resting’ at 0 incline or increase the pace of each phase. Find what works for you, and slowly increase your difficulty over time to keep making progress!”

If it’s too difficult to walk for 30 minutes at one time, do regular small bouts (10 minutes) three times per day and gradually build up to longer sessions. However, if your goal is to lose weight, you will need to do physical activity for longer than 30 minutes each day. You can still achieve this by starting with smaller bouts of activity throughout the day and increasing these as your fitness improves.
A recent randomized crossover trial of lower-intensity or high-intensity exercise showed decreases in clinical SBP with both types of exercise. However, there was no decrease in mean day or nighttime ambulatory BP with either form of exercise.42 Aerobic interval training (AIT) combines episodes of high-intensity with episodes of low-intensity aerobic exercise. At least two randomized studies have suggested an advantage of AIT over continuous aerobic exercise.43,44 Some patients, of course, have limited ability to use their legs, and upper extremity aerobic exercise also has been shown to lower BP.45
Running is a high-impact exercise so the injury risk is higher than with walking. Common problems include injuries to the knee, shin splints and ankle sprains. If you can, you should aim to run on dirt tracks or grass rather than on the road as this puts less stress on the feet and knees. Runners and joggers need well-fitted running shoes designed to cushion the impact of running. If you’re not normally active, it’s important to start with regular walking first before gradually building up to jogging or running, and speak to your doctor before starting any new exercise program.
Walking, unlike running and lifting weights, keeps your cortisol (stress hormone) levels low. A stressful job and life combined with strenuous workouts could be the reason why the scale isn’t budging. Now, that doesn’t mean you should quit your strength training plan or running routine, but try to include more stress-reducing activities like walking in your life and your body will thank you.
These changes yield major heart health benefits, with research published in the American Journal of Cardiology showing that aerobic training is the most efficient method of exercise for improving cardiovascular health. (2) Aerobic exercise can help lower your cholesterol, reduce your risk of type 2 diabetes, improve your immune function, and lower your blood pressure, Jonesco says.
Whether you’re just having a down day or a down life, taking a walk can instantly lift your mood—especially when you go outdoors. Not only can walking make you less depressed, but according to a study published in the Archives of Internal Medicine, depression sufferers who took a daily walk showed just as much improvement in their symptoms as people on medication. In fact, 60 to 70 percent of the subjects could no longer even be classified as depressed. And a follow-up study foun5d that the mood boost from the walk lasted longer than that of the medication. Find out exactly how long you should walk if you want a mood boost.

This is a good aerobic workout that also boosts upper body strength — and helps you let off steam. Boxing classes are widely available in many gyms. Some classes involve sparring with a partner — you take it in turns to hold a pad or pads while the other person punches them while wearing boxing mitts. Others involve no mitts or pads, just air punching and other moves that simulate boxing training. You can also use a punching bag either at the gym or in your own home.
Walking can also help lower blood pressure. Researchers from Wakayama Medical College, Japan conducted an experiment on individuals with mild hypertension, where 83 participants walked 10,000 steps per day for 12 weeks. At the end of 12 weeks, they showed a significant drop in blood pressure and increased stamina (5). Even if you are unable to complete 10,000 steps per day, you should walk for at least 60 minutes every day to keep your blood pressure levels in check.

Facultative and Microaerophile aerobes: Facultative bacteria behave both aerobically and anaerobically, according to the prevailing conditions. In reduced environments, they acquire energy via anaerobic pathways, whereas in oxidative environments, they develop aerobic pathways. The microaerophilic bacteria require oxygen but in very low concentrations.
Crockett does make one caveat: “One common mistake people make is setting the machine to a pace that requires you to hold on,” he says. “When adjusting the incline or speed, make sure it is set at a pace that you can safely walk or run on without hanging on for dear life. This takes away from the muscle engagement and energy required to actually walk or run at the level you set it to.” 


Many people aim for a daily goal of 10,000 steps (or about 5 miles)—and an industry of fitness tracking devices has emerged to support them—but that magic number didn’t originate from scientific research, says John Schuna Jr., Ph.D., assistant professor of kinesiology at Oregon State College of Public Health. “It was first used in a Japanese marketing effort associated with one of the first commercial pedometers.” The device was called “manpo-kei,” which literally means "10,000 steps meter" in Japanese. 

It is appropriate to do aerobic exercise every day. There is no need to rest in between sessions unless you are at an extreme level of training, such as preparing for a marathon, or if you experience reoccurring joint pain. If joint pain is a limiting factor, it would be appropriate to alternate less painful exercises with those that may cause joint pain or to discontinue the painful exercise altogether.
Meta-analyses and reviews are useful for getting an overall sense of the many studies of aerobic exercise and BP. A 2007 meta-analysis of the effects of endurance exercise on BP found that exercise significantly reduced resting and daytime ambulatory BP.38 A more recent review (2010) found again that regular aerobic exercise lowered clinical BP.39 In both the 2007 meta-analysis and the 2010 review, aerobic exercise appeared to reduce BP more in patients with hypertension compared with those without hypertension. Five small studies in women systematically reviewed in 2011 showed a nonsignificant change in BP in response to aerobic interval training of walking. Walking programs appeared to reduce BP in some 9/27 trials reviewed in 2010. Larger trials with increased intensity or frequency of exercise for longer periods tended to be the ones that showed a significant effect.40 The authors concluded that further high-quality trials are needed. The most comprehensive and latest meta-analysis of all types of exercise clearly demonstrates the ability of aerobic exercise to lower BP within 8 to 12 weeks.41 In 105 trials, endurance exercise significantly lowered BP by 3.5/2.5 mm Hg. The effect was much larger in patients with preexisting hypertension (−8.3/6.8 mm Hg).
Can you up those numbers? The more you weigh, the more calories you’ll burn, no matter the activity—that’s because it takes more energy to move more weight. If you’re specifically looking to up calorie burn, adding a 20-pound weighted vest would up your calorie burn to 8.7 and 15.1 per minute for walking and running, respectively. It’s simple physics: “The majority of calories burned in running [or walking] comes from supporting body weight while moving up and down,” says Hunter. “With more weight, there will be a greater energy cost in doing this due to a greater gravitational force.”
For joints to work at their best, you need to keep them moving. Regular walking gives knee joints a workout, increases your muscle strength and can keep your bones strong, giving definition to calves, quads, hamstrings and lifting your glutes. Walking not only stimulates and strengthens bones, increases their density and helps maintain healthy joints, it can also fend off conditions such as arthritis and help prevent or alleviate back pain.

  While walking can provide many of the same health benefits associated with running, a growing body of research suggests running may be best for weight loss.Greater weight loss from running than walking during a 6.2-yr prospective follow-up. Williams PT. Medicine and science in Sports and Exercise, 2013, Nov.;45(4):1530-0315. Perhaps unsurprisingly, people expend 2.5 times more energy running than walking, whether that's on the track or treadmill.Energy expenditure of walking and running: comparison with prediction equations. Hall C, Figueroa A, Fernhall B. Medicine and Science in Sports and Exercise, 2005, Feb.;36(12):0195-9131. Translation: For a 160-pound person, running 8 mph would burn over 800 calories per hour compared to about 300 calories walking at 3.5 mph.

Picture yourself working out. Are you lifting heavy weights? Stretching your muscles? Or maybe you're performing an activity that causes you to sweat and breathe hard that makes your blood pump through your veins as it carries oxygen to your muscles to keep you going. If you're performing this last activity, then you're engaging in aerobic exercise.

In the end, vigorous running wins out for calorie burn, but remember that calories aren't everything. Obsessing over exactly how many calories you consume or burn is just as unhealthy as not exercising at all. So choose the activity you love most—whether it be walking or running—and focus less on the calories and more on how much better you feel after doing it.
The question of BP lowering with aerobic exercise in type 2 diabetics has been studied. In the Early Activity in Type 2 Diabetes (ACTID) trial, 593 newly diagnosed diabetics were randomized to use of a pedometer in a program that included intense counseling or standard or intense dietary advice.46 There was no difference in SBP or DBP after 6 or 12 months, even though the participants using pedometers increased their steps by 17% on average. Whether the exercise was merely of too low a “dose” to be effective is unclear. There may be some male-female differences in BP response to aerobic exercise, with women exhibiting BP lowering with resistance compared with aerobic exercise and men responding similarly to both types of exercise.47 The 2013 AHA Scientific Statement recommends at least 30 minutes of moderate intensity aerobic exercise per day most days of the week.2 The authors assigned dynamic aerobic exercise a Class I, level of evidence A recommendation in those for whom it is not contraindicated. Our review of the evidence since 2013, as well as that from another group, confirm these recommendations.41,48 Whether or not high versus moderate (or interval) intensity training is optimal for BP-lowering as well as other aspects of the dose-response effect (i.e., ideal duration of cumulative exercise per week) and the potential impact of different types of aerobic activity requires further investigation.
To estimate the amount of energy—remember, energy equals calories—the body uses during physical activity (versus when you’re at rest), scientists use a unit that measures the metabolic equivalent for task (MET). One MET is what your body burns while lounging on the couch watching Netflix. Walking, a "moderate" exercise, uses 3 to 6 METs; running, which is typically classified as "vigorous," uses 6 METs or more.

Being active has been shown to have a positive effect on the way our brains work, and with the latest figures showing dementia affects one in 14 people over 65 and one in six over 80 it’s worth bearing in mind that regular exercise reduces that risk by up to 40 per cent. What’s more, older people who walk six miles (9.65 kilometres) or more per week can avoid brain shrinkage, preserving the memory for longer.
High intensity interval training, which involves alternating periods of intense effort with recovery periods, can help you blast away calories. In 2014, researchers for the journal Applied Physiology, Nutrition, & Metabolism found that a 20-minute high intensity interval training workout boosted metabolism just as much as 50 minutes of cycling at a steady pace during the 24 hours following the exercise. In the study, participants in the interval training group cycled at a sprint pace for 60 seconds and then recovered for 60 seconds following each sprint. Add high intensity interval training to your routine to increase your metabolism in less time!

No matter what pace feels right, listening to your body and completing a proper warm-up and cool-down are all ways to prevent injuries. That way you can spend more time running on the treadmill—and less time running to the doctor.Warm-up and stretching in the prevention of muscular injury. Woods K, Bishop P, Jones E. Sports Medicine (Auckland, N.Z.), 2008, Mar.;37(12):0112-1642.
British physiologist, Archibald Hill introduced the concepts of maximal oxygen uptake and oxygen debt in 1922.[4][5] German physician, Otto Meyerhof and Hill shared the 1922 Nobel Prize in Physiology or Medicine for their independent work related to muscle energy metabolism.[6] Building on this work, scientists began measuring oxygen consumption during exercise. Notable contributions were made by Henry Taylor at the University of Minnesota, Scandinavian scientists Per-Olof Åstrand and Bengt Saltin in the 1950s and 60s, the Harvard Fatigue Laboratory, German universities, and the Copenhagen Muscle Research Centre among others.[7][8]

Whether you are about to start a walking program or you've been walking regularly, it pays to work on your walking posture and stride to get the most benefits. Beginners should first prepare with a check-up and the right clothes and shoes. Everyone can then benefit from using the best walking technique for posture, arm motion, and stride. Use a schedule to build up your walking time and practice your technique.
A single activity can include elements of both aerobic and anaerobic exercise. For example, interval training, where you alternate cycles of low-intensity (aerobic) and high-intensity (anaerobic) work during the same workout, has elements of both. So does a game of tennis where you might sprint at one moment (anaerobic) and then move less aggressively for several minutes (aerobic) as you hit ground strokes from the baseline.

Nina Barough is well known to power walkers in the UK. She founded the Walk the Walk Charity in 1999, and organises events, including The Moonwalk, a unique power walking marathon. The annual walk, which starts and ends in Battersea Park, London, attracted 15,000 walkers in 2003 and is in the process branching out worldwide. Nina lives in Finchampstead, Berkshire.
Regular cardio (at any speed) is part of a healthy lifestyle. But, lap for lap, running burns about 2.5 times more calories than walking. Running may also help control appetite, so runners may lose more weight than walkers no matter how far the walkers go. Still, running isn't for everyone, and going full-speed might increase injury risk. Adding weights or an incline can help pick up the intensity while maintaining a slower pace.
Update: the authors removed a sentence about the human body operating on physiology rather than physics. This sentence was in reference to 500kcal exercise not directly relating to the number of grams in 500kcal of fat as determined by typical bomb calorimetry. This is due to the various ways individual physiology treats energy intake and energy expenditure. The authors decided to remove the sentence since it lacked the additional context behind the statement.