Skeletal muscle metabolic and ionic adaptations during intense exercise following sprint training in humans

Abstract

The effects of sprint training on muscle metabolism and ion regulation during intense exercise remain controversial. We employed a rigorous methodological approach, contrasting these responses during exercise to exhaustion and during identical work before and after training. Seven untrained men undertook 7 wk of sprint training. Subjects cycled to exhaustion at 130% pretraining peak oxygen uptake before (PreExh) and after training (PostExh), as well as performing another posttraining test identical to PreExh (PostMatch). Biopsies were taken at rest and immediately postexercise. After training in PostMatch, muscle and plasma lactate (Lac(-)) and H(+) concentrations, anaerobic ATP production rate, glycogen and ATP degradation, IMP accumulation, and peak plasma K(+) and norepinephrine concentrations were reduced (P<0.05). In PostExh, time to exhaustion was 21% greater than PreExh (P<0.001); however, muscle Lac(-) accumulation was unchanged; muscle H(+) concentration, ATP degradation, IMP accumulation, and anaerobic ATP production rate were reduced; and plasma Lac(-), norepinephrine, and H(+) concentrations were higher (P<0.05). Sprint training resulted in reduced anaerobic ATP generation during intense exercise, suggesting that aerobic metabolism was enhanced, which may allow increased time to fatigue.

Effects of high-intensity interval training on pulmonary function

“…Other researchers have also found an increased time to exhaustion after HIT Harmer et al, 2000;. Additionally, HR has been found to be lower at a given work rate during exercise tests to exhaustion after HIT Harmer et al, 2000).…”

“…While studies using a two week six session HIT protocol did not see an increase in maximal oxygen uptake, protocols lasting four to eight weeks did find an increase in maximal oxygen uptake with HIT Harmer et al, 2000;Krustrup et al, 2004;MacDougall et al, 1998;. All of the studies mentioned above trained with cycling exercise but one study using running HIT found no change in maximal oxygen uptake over the course of six weeks of training (Marles et al, 2007).…”

“…In a recent study investigating muscle metabolism, the most likely sources of ATP appear to be derived from a higher glycolytic rate via greater pyruvate and/or intramuscular triglyceride oxidation and a larger recruitment of both type I and II muscle fibers (Harmer et al, 2000). Certain markers of ATP production, including creatine phosphate, creatine kinase, resting glycogen content, lactate dehydrogenase, and lactate have been investigated to determine whether an increase in ATP production occurs with training .…”

“…In addition, most studies had subjects exercise three days a week for two weeks, but some studies lasted as long as seven weeks (Burgomaster et al, 2005;Burgomaster et al, 2006;Burgomaster et al, 2008;Gibala et al, 2006;Souissi et al, 2007). Some researchers increased the number of bouts per session as the weeks progressed (Burgomaster et al, 2005;Burgomaster et al, 2006;Burgomaster et al, 2007;Burgomaster et al, 2008;Gibala et al, 2006;Harmer et al, 2000;Juel et al, 2004;MacDougall et al, 1998;Rakobowchuk et al, 2008) and some kept it at a consistent number . Exercise duration and frequency may lead to variability in training adaptations.…”

The Influence of Different Types of Rest on Football Players’ Ability to Repeat Phosphagen Exercise

“…It should be noted that in our study the ratio of exercise time to pause time was 1 to 12 ±1. Implementation of more work during the first test may be related to an increased volume of blood flowing through the muscles, providing them with significant amounts of oxygen, which can improve lactate transport from the muscles by MCT transporters (Brookes, 1986;Harmer et al, 2000;McKenna et al, 1997). Chmura, Zatoń (2011) suggest that repetition of 90-second efforts might lead to energy from glycolytic processes being used.…”