Second wind

This article is about the exercise phenomenon. For other uses, see Second Wind (disambiguation).

Second wind is a phenomenon in endurance sports, such as marathons or road running (as well as other sports), whereby an athlete who is out of breath and too tired to continue (known as "hitting the wall"), finds the strength to press on at top performance with less exertion. The feeling may be similar to that of a "runner's high", the most obvious difference being that the runner's high occurs after the race is over.[1] In muscle glycogenoses (muscle GSDs), an inborn error of carbohydrate metabolism impairs either the formation or utilization of muscle glycogen. As such, those with muscle glycogenoses do not need to do prolonged exercise to experience "hitting the wall". Instead, signs of exercise intolerance, such as an inappropriate rapid heart rate response to exercise, are experienced from the beginning of an activity, and some muscle GSDs can achieve second wind within about 10 minutes from the beginning of the aerobic activity, such as walking. (See below in pathology).

In experienced athletes, "hitting the wall" is conventionally believed to be due to the body's glycogen stores being depleted, with "second wind" occurring when fatty acids become the predominant source of energy.[2][3][4][5][6] The delay between "hitting the wall" and "second wind" occurring, has to do with the slow speed at which fatty acids sufficiently produce ATP (energy); with fatty acids taking approximately 10 minutes, whereas muscle glycogen is considerably faster at about 30 seconds.[5][7] Some scientists believe the second wind to be a result of the body finding the proper balance of oxygen to counteract the buildup of lactic acid in the muscles.[8] Others claim second winds are due to endorphin production.

Heavy breathing during exercise also provides cooling for the body. After some time the veins and capillaries dilate and cooling takes place more through the skin, so less heavy breathing is needed. The increase in the temperature of the skin can be felt at the same time as the "second wind" takes place.

Documented experiences of the second wind go back at least 100 years, when it was taken to be a commonly held fact of exercise.[9] The phenomenon has come to be used as a metaphor for continuing on with renewed energy past the point thought to be one's prime, whether in other sports, careers, or life in general.[10][11][12]

  1. ^ "Runner Glossary". Road Runner Sports.
  2. ^ Smyth, Barry (2021-05-19). Piacentini, Maria Francesca (ed.). "How recreational marathon runners hit the wall: A large-scale data analysis of late-race pacing collapse in the marathon". PLOS ONE. 16 (5): e0251513. Bibcode:2021PLoSO..1651513S. doi:10.1371/journal.pone.0251513. ISSN 1932-6203. PMC 8133477. PMID 34010308.
  3. ^ Rapoport, Benjamin I. (2010-10-21). Bourne, Philip E. (ed.). "Metabolic Factors Limiting Performance in Marathon Runners". PLOS Computational Biology. 6 (10): e1000960. Bibcode:2010PLSCB...6E0960R. doi:10.1371/journal.pcbi.1000960. ISSN 1553-7358. PMC 2958805. PMID 20975938.
  4. ^ M.D, Paul G. Donohue. "'Second wind' indicates body has switched to fat for its fuel". New Bedford Standard-Times. Retrieved 2023-02-23.
  5. ^ a b "Hormonal Regulation of Energy Metabolism - Berne and Levy Physiology, 6th ed". doctorlib.info. Retrieved 2023-02-23.
  6. ^ Bhai, Salman. "Neuromuscular Notes: Diagnosing Metabolic Myopathies". Practical Neurology. Retrieved 2023-07-31.
  7. ^ "Article - CrossFit: Forging Elite Fitness". journal.crossfit.com. Retrieved 2023-02-23.
  8. ^ Cite error: The named reference Gontang was invoked but never defined (see the help page).
  9. ^ William James (1907). "The Energies of Men".
  10. ^ "A Second Wind". Time. March 29, 1971. Archived from the original on June 4, 2011.
  11. ^ Christopher Clarey (January 28, 2002). "Capriati Barely Outlasts Hingis in a Well-Heated Match". International Herald Tribune.
  12. ^ Jacques Steinberg (May 17, 2007). "Charles Gibson Enjoys a Second Wind on ABC". New York Times.