Many studies show that the faster you walk, the longer you live. Picking up the pace is more healthful than just walking slowly, even if you go longer than the recommended 30 minutes per day.  Paul T. Williams, a statistician at Lawrence Berkeley National Laboratory, followed almost 40,000 men and women who walked for exercise and found that those who walked at a very slow pace (24 minutes per mile) were 44 percent more likely to die within the 10-year study period than those who walked at a faster pace (PLoS One, December 2013).  Other studies showing similar results include:

• A study of 412,596 British citizens, of average age 68, found that compared to slow walkers, people who walked fast had half the chance of developing severe COVID-19 disease and half the chance of dying from that disease. (International Journal of Obesity, Feb 26, 2021;45:1155–1159).
• A review of more than 200,000 cancer survivors, ages 50 to 71, found that those who walked fast had half the death rate when compared to those who walked slowly (Canc Epid, Biomar & Prevent, April, 2021).
• An analysis of 50,225 walkers found that the faster people walk, the lower their risk of dying from a heart attack and from all causes (Br J of Sprts Med, May 31, 2018;52(12):761-768).
• Among older runners, the faster runners had lower blood pressure, lower cholesterol and lower blood sugar levels (Med Sci Sprt Exer, October 2008).
• A review of 14 studies on walking and seven studies on cycling showed that the faster people walked or cycled, the less likely they were to suffer a heart attack (Int J Behav Nutr Phys Act, 2014;11:132).
• A review of 13 studies found that fast walkers had a 31 percent reduction in risk of death from a heart attack when compared to very slow walkers (Br J Sports Med, 2008;42:238–43).
• A review of 250,000 adults in the UK found walking to work was associated with a 36 percent greater reduction in risk of death from a heart attack, compared to those who did not walk to work (BMJ, 2017;357:j1456).
• The Copenhagen City Heart Study found that risk for heart failure was associated far more with how fast a person walked than with how much and how far he walked (PLoS One 2014;9:e89909).
• A study of 73,743 postmenopausal women aged 50–79 years found that the faster a woman walked, the less likely she was to suffer a heart attack (N Engl J Med 2002;347:716–25).
• The Whitehall study, a 40-year follow-up of 6981 British civil servants, found that faster walkers were less likely to die from heart attacks or cancer (Ann Epidemiol, 2010;20:661–9).
• An analysis of 420,000 UK individuals found that walking fast was associated with reduced risk for death from all causes and heart attacks (Eur Heart J, 2017;38:3232–40).

How to Walk Faster
Walking is one of the safest and most effective sports for fitness, but to become fit, you have to move fairly fast. Healthy people should exercise vigorously enough to increase their heart rates at least 20 beats a minute more than when they rest. Walking at a leisurely pace will not raise your heart rate very much. There are two ways to walk faster: take longer steps or move your feet at a faster rate. To lengthen your stride, twist your hips from side to side and reach forward with your feet. Pointing your feet forward after your heel strikes the ground helps you gain a few inches.

It is easier for most people to move their legs faster, rather than to try to lengthen their stride. If you move your arms faster, your feet will move faster also. Every time one leg moves forward, the arm on the same side moves back and the arm on the other side moves forward. For every step forward, there is an equal number of arm movements forward. To move your arms faster, you have to keep your elbows bent. The fulcrum of your arm swing is at your shoulder. The straighter your elbows, the longer your arms swing as a pendulum from your shoulder, reducing the frequency of arm swings. Bending your elbows shortens the swing and allows you to move faster. You may find that it helps to count out a cadence to yourself as you walk, 1-2-3-4, 1-2-3-4 — as if you were marching — or hum a tune, or play some peppy music. (Don’t use earphones if you are walking in traffic). See How to Do Interval Training 

CAUTION: People with blocked arteries leading to their hearts can suffer heart attacks with intense exercise. Check with your doctor before starting a new program of intense exercise or increasing the intensity of your current program.