Monitoring high-intensity endurance training using neuromuscular excitability to recognize overtraining

1997 ◽  
Vol 76 (2) ◽  
pp. 187-191 ◽  
Author(s):  
M. Lehmann ◽  
S. Baur ◽  
N. Netzer ◽  
U. Gastmann
2007 ◽  
Vol 293 (1) ◽  
pp. R392-R401 ◽  
Author(s):  
Andrew M. Jones ◽  
Daryl P. Wilkerson ◽  
Nicolas J. Berger ◽  
Jonathan Fulford

We hypothesized that a period of endurance training would result in a speeding of muscle phosphocreatine concentration ([PCr]) kinetics over the fundamental phase of the response and a reduction in the amplitude of the [PCr] slow component during high-intensity exercise. Six male subjects (age 26 ± 5 yr) completed 5 wk of single-legged knee-extension exercise training with the alternate leg serving as a control. Before and after the intervention period, the subjects completed incremental and high-intensity step exercise tests of 6-min duration with both legs separately inside the bore of a whole-body magnetic resonance spectrometer. The time-to-exhaustion during incremental exercise was not changed in the control leg [preintervention group (PRE): 19.4 ± 2.3 min vs. postintervention group (POST): 19.4 ± 1.9 min] but was significantly increased in the trained leg (PRE: 19.6 ± 1.6 min vs. POST: 22.0 ± 2.2 min; P < 0.05). During step exercise, there were no significant changes in the control leg, but end-exercise pH and [PCr] were higher after vs. before training. The time constant for the [PCr] kinetics over the fundamental exponential region of the response was not significantly altered in either the control leg (PRE: 40 ± 13 s vs. POST: 43 ± 10 s) or the trained leg (PRE: 38 ± 8 s vs. POST: 40 ± 12 s). However, the amplitude of the [PCr] slow component was significantly reduced in the trained leg (PRE: 15 ± 7 vs. POST: 7 ± 7% change in [PCr]; P < 0.05) with there being no change in the control leg (PRE: 13 ± 8 vs. POST: 12 ± 10% change in [PCr]). The attenuation of the [PCr] slow component might be mechanistically linked with enhanced exercise tolerance following endurance training.


1996 ◽  
Vol 81 (2) ◽  
pp. 619-626 ◽  
Author(s):  
D. Gute ◽  
C. Fraga ◽  
M. H. Laughlin ◽  
J. F. Amann

The objective of this study was to test the hypothesis that an endurance training program designed to produce recruitment of all extensor muscle fiber types during each exercise bout would stimulate capillary angiogenesis throughout rat gastrocnemius and soleus muscles. Male Sprague-Dawley rats were exercise trained 5 days/wk for 12–14 wk with exercise bouts consisting of a combination of high intensity (32 m/min on a 15% incline) and long duration (90 min/day). On completion of high-intensity endurance training (HIET) or cage activity [sedentary (Sed)], rat hindquarters were vascularly isolated and perfusion fixed with a modified Karnovsky's fixative. Capillary supply was measured in soleus and gastrocnemius muscles by using Olympus Cue 2 image-analyzer software. Capillary supply was reflected in measurements of capillary-to-fiber ratio, capillary numerical density, capillary surface area density, and capillary volume density on transversely cut tissue sections. HIET increased citrate synthase activity by 20 and 42% in the medial and long heads of the triceps brachii, respectively. Sarcomere lengths were similar in gastrocnemius and soleus muscles of Sed and HIET rats after fixation. All four indexes of capillary supply were significantly greater throughout the gastrocnemius muscle of HIET rats compared with Sed values. The relative increase in capillarity was greater in white than in red gastrocnemius muscle of HIET rats. HIET also increased capillary supply of soleus muscle. However, only capillary numerical density was statistically greater (19%) in HIET soleus compared with Sed. These results support the hypothesis that this training program would produce an increase in capillary supply in all extensor muscles.


2019 ◽  
Vol 21 (4) ◽  
pp. 194-199
Author(s):  
Mahdi Ghafari ◽  
Ebrahim Banitalebi ◽  
Mohamad Faramarzi

Background and aims: Intermuscular lipolysis disorder plays an important role in insulin resistance and diabetes mellitus and perilipin PLIN5 and PLIN3 are the key proteins in regulating muscle cellular lipolysis. Therefore, the purpose of this study was to examine the relationship between the expression of PLIN3 and PLIN5 protein following endurance training in streptozotocin (STZ) rats. Methods: A number of 24 male Wistar rats were randomly divided into low endurance training group (n = 8), high-intensity training group (n = 8), and control group (n = 8). Diabetes was induced in every rat by STZ injection. Three days after injection, the blood samples were taken from the cut tip of the tails of the mice and animals with blood glucose greater than 300 mg/dL were considered diabetic. The training program included eight weeks of aerobic training at different intensities. Training in high- and low-intensity groups included 22-25 and 5-8 m/min of training. Finally, one-way analysis of variance (ANOVA) and correlation was used to determine the significance of the differences between variables, followed by utilizing Tukey’s post-hoc test for significance. Results: The comparison between the groups by ANOVA showed significant differences in PLIN3 (P=0.0006) and PLIN5 (P=0.012). The results of Tukey post hoc test also demonstrated a statistical difference between the mean values of diabetic control group and high-intensity endurance group regarding PLIN3 (P=0.01) and PLIN5 (P=0.009), but no significant increase was observed in the lowintensity exercise group as compared to the control group (PLIN3, P=0.067 & PLIN5, P=0.44). As regards insulin resistance, there was a significant difference among the three groups (P=0.0001). Eventually, the result of the correlation between PLIN3 and PLIN5 showed similar enhancement by increasing the intensity (P=0.0026). Conclusion: According to research results, high-intensity endurance training increased the expression of PLIN3 and PLIN5 in diabetic specimens and PLIN3 and PLIN5 followed a similar increase pattern in high-intensity training


2019 ◽  
Vol 14 (1) ◽  
pp. 105-112 ◽  
Author(s):  
Andrew J. Carnes ◽  
Sara E. Mahoney

Purpose: This study longitudinally compared changes in running performance (5-km time trial) and fitness (maximal oxygen uptake [VO2max] and body composition [BC]) between polarized training and CrossFit Endurance (CFE) in recreational runners. Methods: Participants (N = 21) completed 12 wk of CFE or polarized endurance training (POL). Both groups trained 5 d·wk−1. POL ran 5 d·wk−1, whereas CFE ran 3 d·wk−1 and performed CrossFit 3 d·wk−1 (run + CrossFit 1 d·wk−1). Intensity was classified as low, moderate, or high (zone 1, 2, or 3) according to ventilatory thresholds. POL was prescribed greater volume (295 [67] min·wk−1), distributed as 85%/5%/10% in Z1/Z2/Z3. CFE emphasized a lower volume (110 [18] min·wk−1) distribution of 48%/8%/44%. Results: POL ran 283 (75.9) min·wk−1 and 47.3 (11.6) km·wk−1, both exceeding the 117 (32.2) min·wk−1 and 19.3 (7.17) km·wk−1 in CFE (P < .001). The POL distribution (74%/11%/15%) had greater total and percentage Z1 (P < .001) than CFE (46%/15%/39%), which featured higher percentage Z3 (P < .001). Time trial improved −93.8 (40.4) s (−6.21% [2.16%]) in POL (P < .001) and −84.2 (65.7) s (−5.49% [3.56%]) in CFE (P = .001). BC improved by −2.45% (2.59%) fat in POL (P = .02) and −2.62% (2.53%) in CFE (P = .04). The magnitude of improvement was not different between groups for time trial (P = .79) or BC (P = .88). Both groups increased VO2max (P ≤ .01), but with larger magnitude (P = .04, d = 0.85) in POL (4.3 [3.6] mL·kg·min−1) than CFE (1.78 [1.9] mL·kg·min−1). Conclusions: Recreational runners achieved similar improvement in 5-km performance and BC through polarized training or CFE, but POL yielded a greater increase in VO2max. Extrapolation to longer distances requires additional research.


2018 ◽  
Vol 32 (7) ◽  
pp. 1852-1860 ◽  
Author(s):  
Mohsen Sheykhlouvand ◽  
Mohammadali Gharaat ◽  
Erfan Khalili ◽  
Hamid Agha-Alinejad ◽  
Farhad Rahmaninia ◽  
...  

2008 ◽  
Vol 40 (Supplement) ◽  
pp. S177
Author(s):  
Jennifer L. Graef ◽  
Kristina L. Kendall ◽  
Abbie E. Smith ◽  
Ashley A. Walter ◽  
Travis W. Beck ◽  
...  

2004 ◽  
Vol 91 (2-3) ◽  
pp. 330-335 ◽  
Author(s):  
Yuefei Liu ◽  
Werner Lormes ◽  
Liangli Wang ◽  
Susanne Reissnecker ◽  
J�rgen M. Steinacker

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