Neuromuscular and circulatory adaptation during combined arm and leg exercise with different maximal work loads.

Full Abstract

Cardiopulmonary kinetics and electromyographic activity (EMG) during exhausting exercise were measured in 8 males performing three maximal combined arm+leg exercises (cA+L). These exercises were performed at different rates of work (mean+/-SD; 373+/-48, 429+/-55 and 521+/-102 W) leading to different average exercise work times in all tests and subjects. VO2 reached a plateau versus work rate in every maximal cA+L exercise (range 6 min 33 s to 3 min 13 s). The three different exercise protocols gave a maximal oxygen consumption (VO2MAX) of 4.67+/-0.57, 4.58+/-0.52 and 4.66+/-0.53 l min(-1) (P=0.081), and a maximal heart rate (HRmax) of 190+/-6, 189+/-4 and 189+/-6 beats min(-1) (P=0.673), respectively. Root mean square EMG (EMGRMS) of the vastus lateralis and the triceps brachii muscles increased with increasing rate of work and time in all three cA+L protocols. The study demonstrates that despite different maximal rates of work, leading to different times to exhaustion, the circulatory adaptation to maximal exercise was almost identical in all three protocols that led to a VO2 plateau. The EMG(RMS) data showed increased muscle recruitment with increasing work rate, even though the HRmax and VO2MAX was the same in all three cA+L protocols. In conclusion, these findings do not support the theory of the existence of a central governor (CG) that regulates circulation and neuronal output of skeletal muscles during maximal exercise.

Author information

Author/s: Brink-Elfegoun, Thibault (T); Holmberg, Hans-Christer (HC); Ekblom, Maria Nordlund (MN); Ekblom, Björn (B);

Affiliation: Department of Physiology and Pharmacology, Karolinska Institute, Stockholm, Sweden. thibault.elfegoun(-atsign-)gih.se

Journal and publication information

Publication Type: Journal Article

Journal: European journal of applied physiology (Eur J Appl Physiol), published in Germany. (Language: eng)

Reference: 2007-Nov; vol 101 (issue 5) : pp 603-11

Dates: Created 2007/10/02; Completed 2008/02/20; Revised 2008/12/18;

PMID: 17690901, status: MEDLINE (last retrieval date: 2/18/2009, IMS Date: )

Sourced from the National Library of Medicine. Abstract text and other information may be subject to copyright.

Comments and Corrections

CommentIn: Eur J Appl Physiol. 2008 Nov;104(4):757-9. (PMID: 18618134)

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