HOME >> BIOLOGY >> NEWS
Deciphering the limits to human maximal exercise performance

It has remained unknown during centuries what is the main factor limiting maximal exercise capacity in humans. During the past century evidence has accumulated suggesting that maximal exercise capacity in humans is limited by the maximal amount of O2 that can be delivered to the active muscles.

A rather important step in this direction was the finding that blood flow may reach maximal values around 2-4 l kg-1 min-1 in the quadriceps muscle during maximal knee extension exercise. Since the mean muscle mass of the quadriceps muscle is about 2.5 kg, it was suggested that this magnitude of perfusion would overwhelm the pumping capacity of the heart (which lies close to 25 l.min-1 in normal young humans) if a similar level of hyperaemia could be elicited during whole body exercise in the majority of active muscles.

By studying elite athletic humans with highly trained arm and legs muscles (cross-country skiers), Dr Jose A. Calbet and a team of Scandinavian colleagues led by Professor Bengt Saltin present, in the forthcoming issue of The Journal of Physiology, conclusive evidence showing that during maximal exercise in the upright position the combined maximal arm and leg blood flows surpass the maximal pumping capacity of the heart.

The latter means that to avoid hypotension during maximal exercise in the upright position, humans must restrain the voracity for blood flow of active muscles. This finding may facilitate the comprehension of several pathologic conditions characterised by reduced exercise tolerance and may guide some new therapeutic approaches.


'"/>

Contact: Kate Stinchcombe
kate.stinchcombe@oxon.blackwellpublishing.com
Blackwell Publishing Ltd.
10-Jun-2004


Page: 1

Related biology news :

1. Deciphering how arteries contribute to hypertension
2. Deciphering the genetic basis of the mosquitos senses
3. Discovery of tiny microbes in ancient Greenland glacier may define limits for life on Earth
4. New approach limits damage after heart attack and improves survival, say Scripps Research scientists
5. Inherent mistrust of research institutions limits minority representation
6. Pleasure boat speed limits can stir up trouble in shallow lakes
7. Vaccination following spinal cord injury: Innovative Weizmann Institute approach limits paralysis
8. Scientists decipher "fail-safe" system that limits gene copying in cells
9. Soil fertility limits forests capacity to absorb excess CO2.
10. Climate change plus human pressure caused large mammal extinctions in late Pleistocene
11. Lycopene slows human prostate tumour growth in mice and combined with vitamin E is even better

Post Your Comments:
*Name:
*Comment:
*Email:


(Date:4/13/2017)... 13, 2017 UBM,s Advanced Design and Manufacturing ... feature emerging and evolving technology through its 3D Printing ... run alongside the expo portion of the event and ... demonstrations focused on trending topics within 3D printing and ... manufacturing event will take place June 13-15, 2017 at the ...
(Date:4/11/2017)... Fla. , April 11, 2017 ... and secure authentication solutions, today announced that it ... Intelligence Advanced Research Projects Activity (IARPA) to develop ... Thor program. "Innovation has been a ... IARPA,s Thor program will allow us to innovate ...
(Date:4/11/2017)... BROOKLYN, N.Y. , April 11, 2017 /PRNewswire-USNewswire/ ... identical fingerprints, but researchers at the New York ... University College of Engineering have found that partial ... fingerprint-based security systems used in mobile phones and ... previously thought. The vulnerability lies in ...
Breaking Biology News(10 mins):
(Date:10/11/2017)... ... October 11, 2017 , ... Disappearing forests and increased emissions are the ... million people each year. Especially those living in larger cities are affected by air ... one of the most pollution-affected countries globally - decided to take action. , “I ...
(Date:10/10/2017)... ... October 10, 2017 , ... For the second time ... US2020 STEM Mentoring Award. Representatives of the FirstHand program travelled to Washington, D.C. ... US2020. , US2020’s mission is to change the trajectory of STEM education in ...
(Date:10/10/2017)... ... October 10, 2017 , ... The Pittcon Program ... honoring scientists who have made outstanding contributions to analytical chemistry and ... 2018, the world’s leading conference and exposition for laboratory science, which will be ...
(Date:10/9/2017)... Texas (PRWEB) , ... October ... ... study published on October 5, 2017, in the medical journal, Epilepsia, Brain ... with the gold standard, video EEG, in detecting generalized tonic-clonic seizures (GTCS) ...
Breaking Biology Technology:
Cached News: