The benefits of interval training / high intensity exercise
Exercise intensity matters
Surge training
Chaotic exercise training
Interval training
Lactic acid threshold
Metabolic Equivalents (METs)
References
Exercise intensity matters
Exercise intensity is the key to improving your health, resilience and longevity. There is nothing magical about running compared to other forms of exercise; it is just that running happens to be the most convenient way for most people to exercise really intensely.
A study published in 2017 found that running for as little as five minutes a day can significantly lower your risk of dying. Runners enjoy a 25 to 40% reduced risk of premature mortality and live approximately 3 years longer than non-runners. However, this study suggests that the benefits of even small amounts of vigorous exercise may be much greater than experts had previously assumed. (6)
Warning. Before doing any intense physical activity, please confirm with your doctor that it is safe for you to do this. Not everyone's health allows for intense physical activity, particularly when doing it for the first time.
Surge training
Varying your exercise level makes it significantly more effective. Although sustained, moderate exercise has enormous benefits for health, longevity and fat-burning, research suggests interval and surge training may be even better. How vigorously can you work out? Your answer may predict how long you will live. Varying your exercise level (interval training) is also much more effective for those trying to lose weight.
Researchers have discovered that people who are able to add short bursts of intense activity to their exercise routine live longer than similar aged subjects who were unable to reach that same intensity level. So whenever you exercise - walk, run, bike or whatever - just throw in a few short spurts of high-intensity effort. It can also boost your fat-burn rate by 36 percent in a couple of weeks! (1)
Surge-training has many other benefits, particularly a high antioxidant effect that reduces the effects of aging and improves health. (7)
Chaotic exercise training
This involves large muscle groups working synergistically in a rapidly changing, unstable environment. This produces far greater benefits in a fraction of the time of any other form of exercise. It better mirrors the natural exercise in the everyday life of our early ancestors, uses more metabolic requirements, increases oxygen consumption and stimulates larger amounts of anti-aging, fat-burning, and hormones such as growth hormone and testosterone.
In another study when moderately active women did a 60-minute cycling workout. Instead of pedalling at the same speed for the whole time, they did 4-minute bursts of high-speed pedalling followed by 2-minute rests. In just two weeks they significantly increased their fat-burning power. (2)
Interval training
An example of interval training would be jogging for a few minutes several times during a long walk. When riding an exercise bike, temporarily increase the resistance level and pedal faster for a few minutes once or twice during your workout.
Physiologist Martin Gibala examined the effects of doing three-minute intervals on a stationary bike. The subjects did 30 seconds of intense pedalling followed by a two or three minute rest, and repeated this five or six times. In 15 to 18 minutes they gained the same muscle-cell adaptations as from an hour and a half to two hour bike ride. (5)
A study found that getting your heart rate up is important in losing weight. Overweight people who cycled or jogged for at least three hours a week had the best outcomes - provided they exercised at a pace that raised their heart and breathing rates. If you are not ready to do anything too strenuous yet, try walking briskly for a couple of hours each week. That's enough to prevent further fat on your belly. (3)
A small study of a group of men found that those who added short and intense bursts of activity to their workouts were able to metabolise more sugars. Each man did a workout on a stationary bike three times a week - for a minimum of 17 minutes. Their sugar metabolism was measured. In the next part of the study they added a couple of 30-second bursts of high-intensity cycling to their workouts. After the bursts, they rested by cycling slowly for 4 minutes. The result? When the men ate the equivalent of a meal's worth of glucose, they metabolised it better after the high-intensity training. (4)
Lactic acid threshold
A study of a group of people in their 50s found that after two years they had hearts that were 20 years younger using a variety of measures. These fifty something year olds had the hearts of thirty year olds after two years of training! These people did six hours per week of moderate aerobic exercise, and one high intensity training session per week. (8)
The study found that the lactate threshold is particularly valuable for improving a wide variety of health and aging measures. The lactate threshold occurs in high intensity exercise when one's oxygen intake is less than one's energy demand. This is the unpleasant lactic acid sensation that occurs during the seconds that you are able to sustain a sprint while going for the absolute max.
This lactic threshold causes mitochondrial biogenesis, the creation of new and observably younger mitochondria in the cells. It increases the mitochondrial production of ATP, the energy molecule. Numerous other benefits also occur, such as:
- Improved insulin sensitivity, combatting metabolic syndrome and diabetes.
- Muscle growth.
- Cardiovascular elasticity and improved circulation.
Metabolic Equivalents (METs)
Interval training should gradually increase your fitness. How vigorously you're able to work out is expressed in metabolic equivalents (METs). One MET is the amount of energy your body uses at rest. METs can be measured by the amount of oxygen your body requires to perform an activity. For example, yoga, walking a dog, and golf expend about 3 METs. Swimming laps, jogging or bicycling more than 15 kph (10 mph) expend around 6 METs. If you can reach at least 85 percent of the MET value predicted for your age group when you work out, then you're in good shape. If not, increase the intensity slowly to improve your exercise capacity.
References
1. Gulati M, Black H R, Shaw L J, Arnsdorf M F, Merz C N, Lauer M S, Marwick T H, Pandey D K, Wicklund R H, Thisted R A.
The prognostic value of a nomogram for exercise capacity in women.
The New England Journal of Medicine 2005 Aug 4;353(5):468-475
2. Talanian J L, et al.
Two weeks of high-intensity aerobic interval training increases the capacity for fat oxidation during exercise in women.
Journal of Applied Physiology 2007 Apr;102(4):1439-1447
3. Slentz C A, Aiken L B, Houmard J A, Bales C W, Johnson J L, Tanner C J, Duscha B D, Kraus W E.
Inactivity, exercise, and visceral fat. STRRIDE: a randomized, controlled study of exercise intensity and amount.
Journal of Applied Physiology 2005 Oct;99(4):1613-1618
4. Babraj J A et al.
Extremely short duration high intensity interval training substantially improves insulin action in young healthy males.
BMC Endocrine Disorders 2009 Jan 28;9:3.
5. Martin J Gibala, Jonathan P Little, Martin van Essen, Geoffrey P Wilkin, Kirsten A Burgomaster, Adeel Safdar, Sandeep Raha, Mark A Tarnopolsky.
Effect of short-term sprint interval training on human skeletal muscle carbohydrate metabolism during exercise and time-trial performance.
Journal of Applied Physiology, 2006 Sep 15; 575(Pt 3): 901-911. Published online 2006 Jul 6. doi: 10.1113/jphysiol.2006.112094.
6. Lee DC, Brellenthin AG, Thompson PD, Sui X, Lee IM, Lavie CJ.
Running as a Key Lifestyle Medicine for Longevity.
Prog Cardiovasc Dis. 29 March 2017. pii: S0033-0620(17)30048-8. doi: 10.1016/j.pcad.2017.03.005.
7. Nocella C, Cammisotto V, Pigozzi F, Borrione P, Fossati C, D'Amico A, Cangemi R, Peruzzi M, Gobbi G, Ettorre E, et al.
Impairment between Oxidant and Antioxidant Systems: Short- and Long-term Implications for Athletes' Health.
Nutrients. 2019; 11(6):1353.
8. Howden EJ, Sarma S, Lawley JS, Opondo M, Cornwell W, Stoller D, Urey MA, Adams-Huet B, Levine BD.
Reversing the Cardiac Effects of Sedentary Aging in Middle Age-A Randomized Controlled Trial: Implications For Heart Failure Prevention.
Circulation. 2018 Apr 10;137(15):1549-1560. doi: 10.1161/CIRCULATIONAHA.117.030617. Epub 2018 Jan 8. PMID: 29311053; PMCID: PMC5893372.