scholarly journals A Novel Method for Classification of Running Fatigue Using Change-Point Segmentation

Sensors ◽  
2019 ◽  
Vol 19 (21) ◽  
pp. 4729 ◽  
Author(s):  
Taha Khan ◽  
Lina E. Lundgren ◽  
Eric Järpe ◽  
M. Charlotte Olsson ◽  
Pelle Viberg
Keyword(s):  
Random Forest ◽  
Blood Lactate ◽  
Change Point ◽  
Vastus Lateralis ◽  
Lactate Concentration ◽  
Treadmill Running ◽  
Vastus Lateralis Muscle ◽  
Semg Signal ◽  
Novel Method

Blood lactate accumulation is a crucial fatigue indicator during sports training. Previous studies have predicted cycling fatigue using surface-electromyography (sEMG) to non-invasively estimate lactate concentration in blood. This study used sEMG to predict muscle fatigue while running and proposes a novel method for the automatic classification of running fatigue based on sEMG. Data were acquired from 12 runners during an incremental treadmill running-test using sEMG sensors placed on the vastus-lateralis, vastus-medialis, biceps-femoris, semitendinosus, and gastrocnemius muscles of the right and left legs. Blood lactate samples of each runner were collected every two minutes during the test. A change-point segmentation algorithm labeled each sample with a class of fatigue level as (1) aerobic, (2) anaerobic, or (3) recovery. Three separate random forest models were trained to classify fatigue using 36 frequency, 51 time-domain, and 36 time-event sEMG features. The models were optimized using a forward sequential feature elimination algorithm. Results showed that the random forest trained using distributive power frequency of the sEMG signal of the vastus-lateralis muscle alone could classify fatigue with high accuracy. Importantly for this feature, group-mean ranks were significantly different (p < 0.01) between fatigue classes. Findings support using this model for monitoring fatigue levels during running.

Determinants of endurance in well-trained cyclists

1988 ◽  
Vol 64 (6) ◽  
pp. 2622-2630 ◽  
Author(s):  
E. F. Coyle ◽  
A. R. Coggan ◽  
M. K. Hopper ◽  
T. J. Walters
Keyword(s):  
Blood Lactate ◽  
Vastus Lateralis ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Submaximal Exercise ◽  
Vastus Lateralis Muscle ◽  
Type I ◽  
Vo2 Max ◽  
Leg Extension ◽  
Competitive Cyclists

Fourteen competitive cyclists who possessed a similar maximum O2 consumption (VO2 max; range, 4.6–5.0 l/min) were compared regarding blood lactate responses, glycogen usage, and endurance during submaximal exercise. Seven subjects reached their blood lactate threshold (LT) during exercise of a relatively low intensity (group L) (i.e., 65.8 +/- 1.7% VO2 max), whereas exercise of a relatively high intensity was required to elicit LT in the other seven men (group H) (i.e., 81.5 +/- 1.8% VO2 max; P less than 0.001). Time to fatigue during exercise at 88% of VO2 max was more than twofold longer in group H compared with group L (60.8 +/- 3.1 vs. 29.1 +/- 5.0 min; P less than 0.001). Over 92% of the variance in performance was related to the % VO2 max at LT and muscle capillary density. The vastus lateralis muscle of group L was stressed more than that of group H during submaximal cycling (i.e., 79% VO2 max), as reflected by more than a twofold greater (P less than 0.001) rate of glycogen utilization and blood lactate concentration. The quality of the vastus lateralis in groups H and L was similar regarding mitochondrial enzyme activity, whereas group H possessed a greater percentage of type I muscle fibers (66.7 +/- 5.2 vs. 46.9 +/- 3.8; P less than 0.01). The differing metabolic responses to submaximal exercise observed between the two groups appeared to be specific to the leg extension phase of cycling, since the blood lactate responses of the two groups were comparable during uphill running. These data indicate that endurance can vary greatly among individuals with an equal VO2 max.

Muscle blood flow during exercise in sedentary and trained hypothyroid rats

1995 ◽  
Vol 269 (6) ◽  
pp. H1949-H1954 ◽  
Author(s):  
R. M. McAllister ◽  
M. D. Delp ◽  
K. A. Thayer ◽  
M. H. Laughlin
Keyword(s):  
Skeletal Muscle ◽  
Blood Flow ◽  
Citrate Synthase ◽  
Vastus Lateralis ◽  
Muscle Blood Flow ◽  
Treadmill Running ◽  
Exercise Intolerance ◽  
Vastus Lateralis Muscle ◽  
Blood Flows ◽  
Vastus Intermedius

Hypothyroidism is characterized by exercise intolerance. We hypothesized that active muscle blood flow during in vivo exercise is inadequate in the hypothyroid state. Additionally, we hypothesized that endurance exercise training would restore normal blood flow during acute exercise. To test these hypotheses, rats were made hypothyroid (Hypo) over 3-4 mo with propylthiouracil. A subset of Hypo rats was trained (THypo) on a treadmill at 30 m/min (15% grade) for 60 min/day 5 days/wk over 10-15 wk. Hypothyroidism was evidenced by approximately 80% reductions in plasma triiodothyronine levels in Hypo and THypo and by 40-50% reductions in citrate synthase activities in high oxidative muscles in Hypo compared with euthyroid (Eut) rats. Training efficacy was indicated by increased (25-100%) citrate synthase activities in muscles of THypo vs. Hypo. Regional blood flows were determined by the radiolabeled microsphere method before exercise and at 1-2 min of treadmill running at 15 m/min (0% grade). Preexercise muscle blood flows were generally similar among groups. During exercise, however, flows were lower in Hypo than in Eut for high oxidative muscles such as the red section of vastus lateralis [277 +/- 24 and 153 +/- 13 (SE) ml.min-1.100 g-1 for Eut and Hypo, respectively; P < 0.01] and vastus intermedius (317 +/- 32 and 187 +/- 20 ml.min-1.100 g-1 for Eut and Hypo, respectively; P < 0.01) muscles. Training (THypo) did not normalize these flows (168 +/- 24 and 181 +/- 24 ml.min-1.100 g-1 for red section of vastus lateralis and vastus intermedius muscles, respectively). Blood flows to low oxidative muscle, such as the white section of vastus lateralis muscle, were similar among groups (21 +/- 5, 25 +/- 4, and 34 +/- 7 ml.min-1.100 g-1 for Eut, Hypo, and THypo, respectively; P = NS). These findings indicate that hypothyroidism is associated with reduced blood flow to skeletal muscle during exercise, suggesting that impaired delivery of nutrients to and/or removal of metabolites from skeletal muscle contributes to the poor exercise tolerance characteristic of hypothyroidism.

Effect of estradiol on the temporal pattern of exercise-induced tissue glycogen depletion in male rats

1993 ◽  
Vol 75 (4) ◽  
pp. 1502-1506 ◽  
Author(s):  
T. P. Rooney ◽  
Z. V. Kendrick ◽  
J. Carlson ◽  
G. S. Ellis ◽  
B. Matakevich ◽  
...  
Keyword(s):  
Temporal Pattern ◽  
Vastus Lateralis ◽  
Treadmill Running ◽  
Male Rats ◽  
Vastus Lateralis Muscle ◽  
Glycogen Depletion ◽  
Muscle Tissues ◽  
Triacylglycerol Content ◽  
Exercise Induced ◽  
Glycogen Sparing

The effect of 17 beta-estradiol 3-benzoate (10 micrograms.01 ml of sunflower oil-1 x 100 g body wt-1) on the temporal pattern of exercise-induced tissue glycogen depletion and tissue lipid availability during submaximal treadmill running was determined in male rats. Animal were administered estradiol or oil for 5 days and were then time matched for motorized treadmill running for 30, 60, 90, or 120 min. Significant depletion of liver, soleus muscle, and red and white vastus lateralis muscle tissue glycogen occurred in oil-administered animals run between 30 and 120 min. The greatest extent of tissue glycogen depletion occurred during the first 30 min of exercise with the rate of glycogen depletion slowing between 30 and 120 min of exercise. Administration of estradiol attenuated the temporal pattern of glycogen depletion in both liver and muscle tissues. Significant depletion of red and white vastus glycogen of estradiol-administered animals did not occur until 90 and 120 min of exercise, respectively. Administration of estradiol significantly increased resting plasma free fatty acids and red and white vastus triacylglycerol content. These data indicate that estradiol administration for 5 days resulted in significant glycogen sparing of liver and muscle tissues during submaximal treadmill running for up to 120 min by altering the temporal pattern of glycogen depletion of male rats secondary to an estradiol-mediated increase in availability of lipid substrate during exercise.

Effects of cocaine on plasma catecholamine and muscle glycogen concentrations during exercise in the rat

1991 ◽  
Vol 70 (3) ◽  
pp. 1323-1327 ◽  
Author(s):  
R. K. Conlee ◽  
D. W. Barnett ◽  
K. P. Kelly ◽  
D. H. Han
Keyword(s):  
Blood Lactate ◽  
Muscle Glycogen ◽  
Glycogen Content ◽  
Vastus Lateralis ◽  
Male Rats ◽  
Vastus Lateralis Muscle ◽  
Plasma Catecholamine ◽  
Plasma Epinephrine ◽  
Exercise Endurance ◽  
Insight Into

This study was designed to test the hypothesis that cocaine (C) alters the normal physiological responses to exercise. Male rats were injected with saline (S) or C (12.5 mg/kg) either intravenously (iv) or intraperitoneally (ip). After injection the animals were allowed to rest for 30 min or were run on the treadmill (26 m/min, 10% grade). At rest plasma epinephrine values were 245 +/- 24 pg/ml in the S group and 411 +/- 43 (ip) and 612 +/- 41 (iv) pg/ml in the C groups (P less than 0.05 between S and C). During exercise plasma epinephrine levels were 615 +/- 32 pg/ml in S and 1,316 +/- 58 (ip) and 1,208 +/- 37 (iv) pg/ml in the C groups (P less than 0.05 between S and C). Similar results were obtained for norepinephrine. Glycogen content in the white vastus lateralis muscle was reduced to 31 +/- 2 mumol/g in S after exercise, but after C and exercise the values were 12 +/- 4 (ip) and 16 +/- 3 (iv) mumol/g (P less than 0.05 between S and C). There was no effect of the drug on this parameter at rest. Blood lactate rose to 4.8 +/- 1.0 (ip) and 5.8 +/- 1.3 (iv) mM in the C groups but to only 3.0 +/- 0.2 in the S group after exercise (P less than 0.05 between S and C). These results show that C and exercise combined exert a more dramatic effect on plasma catecholamine, muscle glycogen, and blood lactate concentrations than do C and exercise alone. They provide further insight into explaining the adverse effects of C on exercise endurance observed previously (Bracken et al., J. Appl. Physiol. 66: 377-383, 1989).

Progressive metabolite changes in individual human muscle fibers with increasing work rates

1987 ◽  
Vol 252 (6) ◽  
pp. C630-C639 ◽  
Author(s):  
J. L. Ivy ◽  
M. M. Chi ◽  
C. S. Hintz ◽  
W. M. Sherman ◽  
R. P. Hellendall ◽  
...  
Keyword(s):  
Blood Lactate ◽  
Vastus Lateralis ◽  
Muscle Fibers ◽  
Lactate Concentration ◽  
Work Load ◽  
Bicycle Ergometer ◽  
Almost All ◽  
Fast Twitch

Muscle biopsies were obtained from vastus lateralis muscles of four volunteers exercising at increasing work rates on a bicycle ergometer. Samples were taken at rest (t1), after a work load 23% below the blood lactate threshold (t2), 23% above this threshold (t3), and at exhaustion (t4). Individual muscle fibers were typed by their lactate dehydrogenase and adenylokinase levels and assayed for lactate, glucose-6-phosphate, and malate, (which preliminary data indicated to be the most responsive to increased activity) as well as ATP and phosphocreatine. The results in three of the four cases indicated that by the time of the t2 sample, almost all fibers, regardless of type, had been recruited. Additionally, there were no major differences in lactate concentration between type 1 and 2 fibers from muscle samples taken at t1, t2, and t3. It is concluded that in a muscle with fast-twitch glycolytic and slow-twitch oxidative fibers, all fibers share in the contraction to a substantial degree, even at moderate work loads, and that both the type 1 and 2 fibers contribute significantly to the initial rise in blood lactate during a graded exercise task. Metabolite responses in type 2 fibers differed in certain respects among the four participants. This is attributed to differences in their training backgrounds and consequent differences in type 2 fiber oxidative enzyme levels.

Adaptation of actomyosin ATPase in different types of muscle to endurance exercise

1975 ◽  
Vol 229 (2) ◽  
pp. 422-426 ◽  
Author(s):  
KM Baldwin ◽  
WW Winder ◽  
JO Holloszy
Keyword(s):  
Atpase Activity ◽  
Specific Activity ◽  
Vastus Lateralis ◽  
Close Correlation ◽  
Treadmill Running ◽  
Vastus Lateralis Muscle ◽  
Actomyosin Atpase ◽  
Different Types ◽  
Phosphofructokinase Activity ◽  
Fast Twitch

Higher concentrations of actomyosin were found in the red portion of the vastus lateralis and in the white portion of the vastus lateralis muscle than in the soleus or heart in rats. A strenuous program of treadmill running lasting 18 wk or longer did not significantly affect the amount of actomyosin recovered from the different types of muscle. No changes in actomyosin ATPase occurred in fast-twitch white (white vastus) or heart muscles in response to the exercise training. In contrast, a decrease of approximately 20% occurred in the specific activity of actomyosin ATPase of fast-twitch red (red vastus) muscle (0.635 +/- 0.029 mumol Pi/min per milligram for sedentary vs. 0.529 +/- 0.021 mumol Pi/min per milligram for trained), while the actomyosin ATPase activity of slow-twitch red (soleus) muscle increased about 20% (0.209 +/- 0.033 vs. 0.257 +/- 0.031 mumol Pi/min per milligram). There was a close correlation (r = 0.99, P less than 0.001) between actomyosin ATPase activity and phosphofructokinase activity in the three types of skeletal muscles and in heart muscle of exercise-trained and untrained animals, providing further evidence in support of the concept that the glycogenolytic capacity of a muscle and its actomyosin ATPase activity are regulated in parallel.

scholarly journals Relationships between maximal muscle oxidative capacity and blood lactate removal after supramaximal exercise and fatigue indexes in humans

2004 ◽  
Vol 97 (6) ◽  
pp. 2132-2138 ◽  
Author(s):  
C. Thomas ◽  
P. Sirvent ◽  
S. Perrey ◽  
E. Raynaud ◽  
J. Mercier
Keyword(s):  
Blood Lactate ◽  
Citrate Synthase ◽  
Vastus Lateralis ◽  
Oxidative Capacity ◽  
Slow Phase ◽  
Vastus Lateralis Muscle ◽  
Supramaximal Exercise ◽  
Muscle Oxidative Capacity ◽  
S Cycling ◽  
Lactate Removal

The present study investigated whether blood lactate removal after supramaximal exercise and fatigue indexes measured during continuous and intermittent supramaximal exercises are related to the maximal muscle oxidative capacity in humans with different training status. Lactate recovery curves were obtained after a 1-min all-out exercise. A biexponential time function was then used to determine the velocity constant of the slow phase (γ2), which denoted the blood lactate removal ability. Fatigue indexes were calculated during all-out (FIAO) and repeated 10-s cycling sprints (FISprint). Biopsies were taken from the vastus lateralis muscle, and maximal ADP-stimulated mitochondrial respiration ( Vmax) was evaluated in an oxygraph cell on saponin-permeabilized muscle fibers with pyruvate + malate and glutamate + malate as substrates. Significant relationships were found between γ2 and pyruvate + malate Vmax ( r = 0.60, P < 0.05), γ2 and glutamate + malate Vmax ( r = 0.66, P < 0.01), and γ2 and citrate synthase activity ( r = 0.76, P < 0.01). In addition, γ2, glutamate + malate Vmax, and pyruvate + malate Vmax were related to FIAO (γ2 − FIAO: r = 0.85; P < 0.01; glutamate + malate Vmax − FIAO: r = 0.70, P < 0.01; and pyruvate + malate Vmax − FIAO: r = 0.63, P < 0.01) and FISprint (γ2 − FISprint: r = 0.74, P < 0.01; glutamate + malate Vmax − FISprint: r = 0.64, P < 0.01; and pyruvate + malate Vmax − FISprint: r = 0.46, P < 0.01). In conclusion, these results suggested that the maximal muscle oxidative capacity was related to blood lactate removal ability after a 1-min all-out test. Moreover, maximal muscle oxidative capacity and blood lactate removal ability were associated with the delay in the fatigue observed during continuous and intermittent supramaximal exercises in well-trained subjects.

Fatigue and exhaustion in chronic hypobaric hypoxia: influence of exercising muscle mass

1994 ◽  
Vol 76 (2) ◽  
pp. 634-640 ◽  
Author(s):  
B. Kayser ◽  
M. Narici ◽  
T. Binzoni ◽  
B. Grassi ◽  
P. Cerretelli
Keyword(s):  
Hypobaric Hypoxia ◽  
Vastus Lateralis ◽  
Lactate Concentration ◽  
Exercise Bout ◽  
Vastus Lateralis Muscle ◽  
O2 Uptake ◽  
Before And After ◽  
Leg Exercise ◽  
Muscle Groups ◽  
Forearm Exercise

Exhaustive dynamic exercise with large muscle groups in chronic hypobaric hypoxia may be limited by central (nervous) rather than peripheral (metabolic) fatigue. Six males [32 +/- 4 (SD) yr] at sea level (SL) and after 1-mo acclimatization at 5,050 m (HA) performed exhaustive dynamic forearm exercise at a constant absolute load, requiring regional maximum aerobic power at SL, and exhaustive cycle exercise at prevailing maximal O2 uptake (HA approximately equal to 80% SL). Exhaustion time (t(ex)), blood O2 saturation (SaO2), and heart rate (HR) were measured during each exercise bout. Before and after both arm and leg exercise, lactate concentration ([La]), PO2, PCO2, and pH were measured in arterialized blood samples. Integrated electromyogram activity (IEMG) and mean (MPF) and centroid (CPF) power frequencies of the EMG power spectrum during exercise were calculated for forearm flexors and vastus lateralis muscle. t(ex) for forearm exercise at the same absolute load was the same at SL and HA. Similar increases of IEMG (+214% at SL vs. +172% at HA) and decreases of CPF (-13% at SL vs. -16% at HA) and MPF (-22% at SL vs. -21% at HA) were observed. By contrast, at HA, for similar t(ex), leg exercise had to be performed at the same relative (i.e., prevailing maximal O2 uptake) but lower absolute load (approximately equal to 80% of SL).(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of previous exercise with arms or legs on metabolism and performance in exhaustive exercise

1975 ◽  
Vol 38 (5) ◽  
pp. 763-767 ◽  
Author(s):  
J. Karlsson ◽  
F. Bonde-Petersen ◽  
J. Henriksson ◽  
H. G. Knuttgen
Keyword(s):  
Blood Lactate ◽  
Vastus Lateralis ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Exercise Bout ◽  
Creatine Phosphate ◽  
The Body ◽  
Exhaustive Exercise ◽  
Leg Exercise ◽  
Muscle Groups

The ability of additional muscles to perform after certain other muscles of the body had been exercised to exhaustion was studied in three male subjects. Exhaustive exercise was performed in two series: series L-A, a bout of leg exercise preceded a bout of arm exercise; series A-L, arm preceded leg (6-min recovery between bouts). Biopsies were taken during the course of each experiment from both the deltoideus and vastus lateralis muscles for determination of ATP, creatine phosphate, lactate, and pyruvate. Exhaustive exercise led to marked elevations in lactate and decreases in ATP and CP in exercised muscle and marked increases in blood lactate concentration. Similar changes, especially in lactate, were observed during and after the first exercise bout in nonexercised muscle. When arm or leg exercise was performed as the second bout, decreases in performance time were observed as compared to performance as the initial bout. It is suggested that the performance potential of muscle is decreased because of internal changes elicited by elevated blood lactate and/or blood H+ concentrations brought about by other muscle groups previously exercised to exhaustion.

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