Biomedical subjects

H Rusko

Publications and source records attributed to H Rusko.

At least 19 recordsLinked to original sources

PubMed2006

The profile and distribution of myosin heavy chain isoforms in middle-aged sedentary persons.

AIM: Human lifestyle has drastically changed during the past century as the share of physical work in daily life has decreased. The purpose of the present study was to examine the distribution of myosin heavy chain (MHC) isoforms in middle-aged sedentary persons, to compare the proportion of MHC isoforms of middle-aged and young sedentary persons and to demonstrate the effect of physical activity of MHC isoforms in middle-aged sedentary persons. METHODS: Eighty-nine middle-aged sedentary and 13 young sedentary persons volunteered for the study. Thirty middle-aged sedentary subjects participated in strength-conditional exercise program during 9 months. Vertical jumping height and maximal anaerobic work capacity were measured. Muscle samples were taken from vastus lateralis muscle. MHC isoform composition was determined by SDS-PAGE. RESULTS: Variation of MHC I and MHC IIa isoforms in middle-age sedentary persons demonstrated normal distribution. Significant differences of MHC isoform proportions between middle-aged and young sedentary participants were not observed. The proportion of MHC IIx decreased significantly after the exercise period that significantly improved the maximal anaerobic power and jumping height of participants. CONCLUSIONS: Normal distribution illustrated the proportion of MHC I and MHC IIa isoforms in 89 middle-aged sedentary persons while significant differences of MHC isoforms proportion between young and middle-aged sedentary persons were not observed. Even small increase of physical activity improved physical performance and decrease the MHC IIx proportion of middle-aged sedentary persons. Physically active lifestyle in middle age, when age-related changes have not started yet, may delay age-related changes in skeletal muscle.

Adult↗

PubMed2005

Role of skeletal muscle-fibre type in regulation of glucose metabolism in middle-aged subjects with impaired glucose tolerance during a long-term exercise and dietary intervention.

AIM: The aim of this study was to investigate the role of skeletal muscle fibre type in the regulation of glucose metabolism in middle-aged obese subjects with impaired glucose tolerance (IGT) during a 2-year exercise and dietary intervention. METHODS: Muscle biopsies (musculus vastus lateralis) were taken from 22 subjects belonging to the intervention group of the Finnish Diabetes Prevention Study [1]. According to their myosin heavy chain (MHC) profile at the baseline, the subjects were divided into two groups: IGT(slow) (n=10) with a high proportion of MHC I isoforms and IGT(fast) (n=12) with a high proportion of MHC II isoforms in the vastus lateralis muscle. The intervention consisted of dietary counselling, strength and power training and/or aerobic exercise. The amount of exercise was the same in both groups; the exercise frequency was 5.1+/-2.7 h/week in the IGT(slow) and 5.1+/-2.8 h/week in the IGT(fast) group. RESULTS: Fasting glucose (p<0.05), 2-h glucose (p<0.05), fasting insulin (p<0.05), haemoglobin A1c (HbA(1c)) (p<0.01) and insulin resistance (p<0.05) [homeostasis model assessment for insulin resistance (HOMA-IR)] decreased in the IGT(fast) group, whereas only the 2-h glucose and HbA(1c) concentrations decreased in the IGT(slow) group. The amount of the glycogen synthase kinase-3-alphabeta (GSK-3-alphabeta) decreased in the IGT(fast) group (p<0.05). Exercise training increased the lactate dehydrogenase (LDH) (p<0.01), LDH-1 (p<0.05) and citrate synthase (CS) (p<0.05) activities in the vastus lateralis muscle in the IGT(slow) group, but only the CS activity (p<0.05) in the IGT(fast) group. CONCLUSIONS: The glucose metabolism improved both in the IGT(slow) and IGT(fast) group during the 2-year exercise and dietary intervention. The change was more prominent in the IGT(fast) group than in the IGT(slow) group, associated with the decrease of the GSK-alphabeta protein expression in skeletal muscle. The exercise training improved both glycolytic and oxidative capacity in the vastus lateralis muscle. The glycolytic capacity improved in the IGT(slow) group and the oxidative capacity in both groups.

Adult↗

PubMed2003

Leucine supplementation does not enhance acute strength or running performance but affects serum amino acid concentration.

This study described the effect of leucine supplementation on serum amino acid concentration during two different exercise sessions in competitive male power athletes. The subjects performed a strength exercise session (SES; n = 16; 26 +/- 4 years) or a maximal anaerobic running exercise session (MARE; n = 12; 27 +/- 5 years) until exhaustion twice at a 7-day interval. The randomized subjects consumed drinks containing leucine (100 mg x kg/body weight before and during SES or 200 mg x kg/body weight before MARE) or placebo. Blood specimens taken 10 min before (B) and after (A) the sessions were analyzed for serum amino acids. In SES the concentration of leucine was distinctly higher in the leucine supplemented group than in the placebo group in both B (p < 0.001) and A (p < 0.001) samples. The leucine concentration decreased in placebo but not in the leucine supplemented group following the exercise session. Isoleucine (p = 0.017) and valine (p = 0.006) concentration decreased more in the leucine supplemented group than in placebo in A samples. In MARE the concentration of leucine was higher in the leucine supplemented group than in placebo in both B (p < 0.001) and A (p < 0.001) samples and increased (p < 0.001) in the supplemented group following the session. Isoleucine (p = 0.020) and valine (p = 0.006) concentration decreased in the supplemented group in A samples. There were no differences in a counter movement jump after SES or in the running performance in MARE between the leucine supplemented group and placebo. These findings indicate that consuming leucine before or before and during exercise sessions results in changes in blood amino acid concentration. However, the supplementation does not affect an acute physical performance.

Adult↗

PubMed2002

Neuromuscular adaptations during concurrent strength and endurance training versus strength training.

The purpose of this study was to investigate effects of concurrent strength and endurance training (SE) (2 plus 2 days a week) versus strength training only (S) (2 days a week) in men [SE: n=11; 38 (5) years, S: n=16; 37 (5) years] over a training period of 21 weeks. The resistance training program addressed both maximal and explosive strength components. EMG, maximal isometric force, 1 RM strength, and rate of force development (RFD) of the leg extensors, muscle cross-sectional area (CSA) of the quadriceps femoris (QF) throughout the lengths of 4/15-12/15 (L(f)) of the femur, muscle fibre proportion and areas of types I, IIa, and IIb of the vastus lateralis (VL), and maximal oxygen uptake (VO(2max)) were evaluated. No changes occurred in strength during the 1-week control period, while after the 21-week training period increases of 21% (p<0.001) and 22% (p<0.001), and of 22% (p<0.001) and 21% (p<0.001) took place in the 1RM load and maximal isometric force in S and SE, respectively. Increases of 26% (p<0.05) and 29% (p<0.001) occurred in the maximum iEMG of the VL in S and SE, respectively. The CSA of the QF increased throughout the length of the QF (from 4/15 to 12/15 L(f)) both in S (p<0.05-0.001) and SE (p<0.01-0.001). The mean fibre areas of types I, IIa and IIb increased after the training both in S (p<0.05 and 0.01) and SE (p<0.05 and p<0.01). S showed an increase in RFD (p<0.01), while no change occurred in SE. The average iEMG of the VL during the first 500 ms of the rapid isometric action increased (p<0.05-0.001) only in S. VO(2max) increased by 18.5% (p<0.001) in SE. The present data do not support the concept of the universal nature of the interference effect in strength development and muscle hypertrophy when strength training is performed concurrently with endurance training, and the training volume is diluted by a longer period of time with a low frequency of training. However, the present results suggest that even the low-frequency concurrent strength and endurance training leads to interference in explosive strength development mediated in part by the limitations of rapid voluntary neural activation of the trained muscles.

Adaptation, Physiological↗

PubMed2002

Effect of hyperoxia on metabolic responses and recovery in intermittent exercise.

The aim of the present study was to investigate whether the breathing of hyperoxic gas affects hemoglobin oxygen saturation (S(a)O(2)) and blood acidosis during intense intermittent exercise and recovery in sprint runners. The hypothesis was that the breathing of hyperoxic gas prevents S(a)O(2) from decreasing, delays blood acidosis during the exercise and improves the rate of heart rate recovery after the exercise. Nine sprinters ran three sets of 300 m at different velocities on a treadmill in normoxia (NOX) and in two hyperoxic conditions (ERHOX and RHOX; F(I)O(2) 0.40) in a randomized order. In ERHOX the inspired air was hyperoxic during the entire exercise and recovery and in RHOX the hyperoxic air was only inhaled during recovery periods. Blood pH and S(a)O(2) were measured from fingertip blood samples taken after each set of runs. The mean heart rate for the final 15 s of the last run in each set (HR(work)), the mean heart rate for the final 15 s of the first minute of recovery (HR(rec)) and the difference of HR(work) and HR(rec) (HR(dec)) were determined. In NOX, S(a)O(2) decreased from 95.0 +/- 2.0% to 88.7 +/- 2.0% (p < 0.001) but S(a)O(2) did not change in ERHOX (from 95.4 +/- 1.3% to 95.9 +/- 1.8%). A significant correlation was observed between the S(a)O(2) decrease in NOX and the effect of hyperoxia on blood pH in ERHOX (r = 0.63) and on HRdec in both ERHOX (r = 0.74) and RHOX (r = 0.69). We concluded that hemoglobin oxygen de-saturation occurred during intensive intermittent exercise in normoxia but hyperoxic gas during the exercise prevents S(a)O(2) from decreasing. Furthermore, the present results suggested that the beneficial effects of hyperoxia on heart rate recovery and blood acidosis during intensive intermittent exercise were related to hemoglobin de-saturation in normoxia.

Exercise↗

PubMed2000

Changes in hemoglobin values in elite cross-country skiers from 1987-1999.

Hemoglobin data have been available from ski teams beginning from 1987, and from 1989 to 1999 we have followed hemoglobin values in elite cross-country skiers in international competitions. The mean values at the 1989 World Nordic Ski Championships were lower than population reference values, as would be expected from plasma volume expansion associated with endurance training. However, an increase, particularly in the maximal values, became obvious in 1994 and rose further in 1996. These extreme values provide both a health risk to the individual athlete and unfair competition. After a rule limiting hemoglobin values was introduced, the drop of the highest values was remarkable: among men 15 g/l (0.23 mmol/l) and among women 42 g/l (0.65 mmol/l). It would appear that the rule had achieved its goal of limiting extreme hemoglobin values. Yet the mean hemoglobin concentrations in men and women have continued to rise, suggesting the continued use of artificial methods to increase total hemoglobin mass.

Acclimatization↗

PubMed2000

Muscle power factors and VO2max as determinants of horizontal and uphill running performance.

This study was carried out to investigate the importance of maximal oxygen uptake (VO2max) and so-called muscle power factors relating to neuromuscular and anaerobic characteristics as determinants of peak horizontal and uphill treadmill running velocity (Vmax). Muscle power factors were measured as peak velocity (VMART) and blood lactate concentration (BlaMART) in a maximal anaerobic running test and as maximal 30-m run velocity (V30m). Seven middle-distance runners, eight triathletes and eight cross-country skiers performed an incremental VO2max-test at horizontal (subscript max0) and 7 degrees uphill (subscript max7) and the MART at 3 degrees uphill on a treadmill and V30m-test on a track. The MART consisted of n x 20-s runs with a 100-s recovery between the runs and the velocity was increased by 0.41 m x s(-1) for each consecutive run until exhaustion. At 0 degrees Vmax was significantly higher but VO2max, ventilation and Bla were significantly lower than at 7 degrees inclination. Vmax0 correlated with VMART (r=0.85, P<0.001), Blamax0 (r=0.49, P<0.05) and V30m (r=0.78, P<0.001) but not with VO2max0. Vmax7 correlated with VO2max7 (r=0.78, P<0.001), VMART (r=0.61, P<0.01) and V30m (r=0.53, P<0.05). VMART correlated with BlaMART (r=0.71, P<0.01) and V30m (r=0.96, P<0.001) but not with VO2max0 or VO2max7. Middle-distance runners had a significantly (P<0.001) higher Vmax0, VMART BlaMART and V30m than triathletes and cross-country skiers, but no significant differences were found between the three groups in VO2max0, VO2max7 or Vmax7. We conclude that so-called muscle power factors, e.g. VMART, V30m and BlaMART, contribute to peak treadmill running performance and especially to horizontal running performance and that VO2max contributes more to uphill than horizontal running performance.

Anaerobiosis↗

PubMed2000

Comparison of physiological strain and muscular performance of athletes during two intermittent running exercises at the velocity associated with VO2max.

The purpose of this study was to examine physiological strain and muscular performance responses of well trained athletes during two intermittent running exercise protocols at the velocity associated with VO2max. Ten national level middle-distance runners (VO2max 69.4+/-5.1; mean+/-SD) performed in random order two 28 min treadmill running exercises: 14 bouts of 60 s runs with 60 s rest (IR60) and 7 bouts of 120 s runs with 120 s rest between each run (IR120). During IR120 peak oxygen uptake (12%), peak heart rate (3%) and peak blood lactate (79%) were significantly higher than during IR60 (P< 0.001) and almost the same as in the VO2max test. In IR120 the relative aerobic energy release calculated on the basis of the accumulated oxygen deficit during the running bouts was significantly higher than in IR60 (81.5+/-2.7 vs. 70.2+/-2.6%, P<0.001) likewise the sum oxygen consumption during the 14 min running (P< 0.001), while during the 14 min recovery it was as much lower (P < 0.001). There were no changes either during or between the IR60 and IR120 protocols with regard to the muscular performance parameters, stride length or height of maximal vertical jumps. In conclusion, during intermittent running at the velocity associated with VO2max doubling the duration of work and rest bouts from 60 s to 120s increased the physiological strain of well trained athletes to the same level as at exhaustion in the VO2max test but the muscular performance variables were not influenced.

Adult↗

PubMed2000

Acclimatization to altitude and normoxic training improve 400-m running performance at sea level.

To investigate the benefits of 'living high and training low' on anaerobic performance at sea level, eight 400-m runners lived for 10 days in normobaric hypoxia in an altitude house (oxygen content = 15.8%) and trained outdoors in ambient normoxia at sea level. A maximal anaerobic running test and 400-m race were performed before and within 1 week of living in the altitude house to determine the maximum speed and the speeds at different submaximal blood lactate concentrations (3, 5, 7, 10 and 13 mmol x l(-1)) and 400-m race time. At the same time, ten 400-m runners lived and trained at sea level and were subjected to identical test procedures. Multivariate analysis of variance indicated that the altitude house group but not the sea-level group improved their 400-m race time during the experimental period (P < 0.05). The speeds at blood lactate concentrations of 5-13 mmol x l(-1) tended to increase in the altitude house group but the response was significant only at 5 and 7 mmol x l(-1) (P < 0.05). Furthermore, resting blood pH was increased in six of the eight altitude house athletes from 0.003 to 0.067 pH unit (P < 0.05). The results of this study demonstrate improved 400-m performance after 10 days of living in normobaric hypoxia and training at sea level. Furthermore, the present study provides evidence that changes in the acid-base balance and lactate metabolism might be responsible for the improvement in sprint performance.

Acclimatization↗

PubMed2000

EPO, red cells, and serum transferrin receptor in continuous and intermittent hypoxia.

PURPOSE: Erythropoietic response in 10 healthy nonsmoking volunteers exposed to normobaric hypoxia continuously or intermittently 12 h daily for 7 d was evaluated in a randomized cross-over study. METHODS: An oxygen content of 15.4% corresponding to an altitude of 2500 m was created by adding nitrogen into room air in a flat. Venous blood samples for hemoglobin (Hb), hematocrit (Hct), reticulocytes, serum erythropoietin (S-EPO), red cell 2,3-diphosphoglycerate (2,3-DPG), serum ferritin (S-Ferrit), and serum soluble transferrin receptor (S-TransfR) were drawn at 8:00 a.m. RESULTS: S-EPO was increased from baseline values of 22.9+/-9.6 and 20.5+/-10.1 U x L(-1) to 40.7+/-12.9 (P < 0.05) and 35+/-14.3 U x L(-1) (P < 0.05) after the first night in continuous and intermittent hypoxia, respectively, and remained elevated throughout both exposures. Hb and Hct values did not show any significant changes. Red cell 2,3-DPG rose from baseline a value of 5.0+/-0.8 to 5.9+/-0.7 mmol x L(-1) (P < 0.05) after the first day in continuous hypoxia and from 5.2+/-0.7 mmol x L(-1) to 6.1+/-0.5 mmol x L(-1) on day 3 (P < 0.05) during intermittent hypoxia. The reticulocyte count rose significantly (P < 0.05) after 5 d in both experiments. S-transferrin receptor level rose significantly from 2.2+/-0.4 and 2.1+/-0.5 mg x L(-1) to 2.6+/-0.5 mg x L(-1) and 2.3+/-0.6 mg x L(-1) on day 5 (P < 0.05), to 2.7+/-0.5 mg x L(-1) and 2.5+/-0.6 mg x L(-1) on day 7 (P < 0.05) under continuous and intermittent hypoxia, respectively. CONCLUSIONS: We suggest that intermittent exposure to moderate normobaric hypoxia 12 h daily for 1 wk induces a similar stimulation of erythropoiesis as continuous exposure.

Adult↗

PubMed1999

Neuromuscular characteristics and fatigue during 10 km running.

This study investigated neuromuscular characteristics and fatigue during 10 km running (10 K) performance in well-trained endurance athletes with different distance running capability. Nine high (HC) and ten low (LC) caliber endurance athletes performed the 10 K on a 200 m indoor track, constant velocity lap (CVL, 4.5 m x s(-1)) 5 times during the course of the 10 K and maximal 20 m speed test before (20 m(b)) and after (20 m(a)) the 10 K. Running velocity (V), ground contact times (CT), ground reaction forces (F) and electromyographic activity (EMG) of the leg muscles (vastus lateralis; VL, biceps femoris; BF, gastrocnemius; GA) were measured during 20 m(b), 20 m(a), and CVLs. The 10 K times differed (p<0.001) between HC and LC (36.3+/-1.2 and 39.2+/-2.0 min, respectively) but no differences were observed in 20 m(b) velocity. The 10 K led to significant (p<0.05) decreases in V, F and integrated EMG (IEMG) and increases in CTs of 20 m(a) in both groups. No changes were observed in HC or LC in F and IEMG during the CVLs but HC showed shorter (p<0.05) mean CT of CVLs than LC. A significant correlation (r = -0.56, p<0.05) was observed between the mean CT of CVLs and velocity of 10 K (V10K). Pre-activity of GA in relation to the IEMG of the total contact phase during the CVLs was higher (p<0.05) in HC than LC. The relative IEMGs of VL and GA in the propulsion phase compared to the IEMG of the 20 m(b) were lower (p<0.05) in HC than LC. In conclusion, marked fatigue took place in both HC and LC during the 10 K but the fatigue-induced changes in maximal 20 m run did not differentiate endurance athletes with different V10K. However, a capability to produce force rapidly throughout the 10 K accompanied with optimal preactivation and contact phase activation seem to be important for 10 km running performance in well trained endurance athletes.

Adult↗

PubMed1999

Explosive-strength training improves 5-km running time by improving running economy and muscle power.

To investigate the effects of simultaneous explosive-strength and endurance training on physical performance characteristics, 10 experimental (E) and 8 control (C) endurance athletes trained for 9 wk. The total training volume was kept the same in both groups, but 32% of training in E and 3% in C was replaced by explosive-type strength training. A 5-km time trial (5K), running economy (RE), maximal 20-m speed (V20 m), and 5-jump (5J) tests were measured on a track. Maximal anaerobic (MART) and aerobic treadmill running tests were used to determine maximal velocity in the MART (VMART) and maximal oxygen uptake (VO2 max). The 5K time, RE, and VMART improved (P < 0.05) in E, but no changes were observed in C. V20 m and 5J increased in E (P < 0.01) and decreased in C (P < 0.05). VO2 max increased in C (P < 0.05), but no changes were observed in E. In the pooled data, the changes in the 5K velocity during 9 wk of training correlated (P < 0.05) with the changes in RE [O2 uptake (r = -0.54)] and VMART (r = 0.55). In conclusion, the present simultaneous explosive-strength and endurance training improved the 5K time in well-trained endurance athletes without changes in their VO2 max. This improvement was due to improved neuromuscular characteristics that were transferred into improved VMART and running economy.

Adult↗

PubMed1997

The effect of endurance exercise at moderate altitude on serum lipid peroxidation and antioxidative functions in humans.

We investigated the effect of training and racing at moderate altitude (MA) on oxidative stress by assessment of serum diene conjugation (DC) and serum antioxidant potential (TRAP). Nine male top level skiers were studied during a national race (20-30 km) at sea level (SL). Thereafter, the athletes trained for 2 weeks at MA, after which they participated in a 20-30 km race at MA. Venous blood samples were taken before and after the race. The DC, indicating early events of lipid peroxidation, did not change during the race at SL (16 850 vs 15 900 delta Absorbance.l-1) or at MA (19 870 vs. 20 630 delta Abs.l-1). At MA serum DC was higher than at SL both before (25%) and after (30%) the race, the postrace difference being statistically significant (P < 0.05). The TRAP increased during the race at MA (from 1387 to 1943 mumol.l-1, P = 0.016), but not at SL (1713 vs 1582 mumol.l-1). These observations would suggest that the level of oxidative stress might be greater during living, training and racing at MA (higher DC levels). Increased TRAP during the race at MA may indicate that the physiological adaptation to extreme acute oxidative stress was altered. The physiological significance of this observation remains to be investigated.

Adult↗

PubMed1996

EMG-activity and muscular performance of lower leg during stretch-shortening cycle after cooling.

To test the effect of cooling on EMG-activity of muscles working as an agonist and antagonist in the lower leg, 12 men dressed in shorts and jogging shoes performed a drop-jump exercise after 60 min exposures to 27 degrees C and 10 degrees C. Cooling decreased mean skin temperature 5.6 +/- 0.4 degrees C (mean +/- SD, P < 0.001), whereas rectal temperature was unaffected. The muscle temperature measured from m. gastrocnemius medialis decreased 4.1 +/- 0.3 degrees C (P < 0.01) at the depth of 30 mm below skin surface. To find the optimal stretching velocity for potentiation of elastic energy, the drop-jump exercise was performed from six different bench heights (10, 20, 30, 40, 50, and 60 cm). The optimal velocity was not altered on account of cooling. In cooled subjects during the stretch phase of the drop jumps the EMG-activity of m. triceps surae complex (agonist) increased (P < 0.05-0.001) while the activity of m. tibialis anterior (antagonist) remained unchanged. After cooling during the shortening phase of the jumps the EMG-activity of m. triceps surae complex decreased (P < 0.05-0.001), whereas the activity of m. tibialis anterior increased (P < 0.05-0.001). In addition, after cooling the peak EMG-activity appeared on the average 28 ms earlier, which shifted the peak activity from the shortening phase (at 27 degrees C) to the stretch phase (at 10 degrees C). Cooling increased the mean duration of stretch and shortening phases by 28 +/- 3 ms (P < 0.001) and 23 +/- 2 ms (P < 0.001), respectively. The average force production during the shortening phase was 26% less (P < 0.05) after cooling, which resulted in a decreased rise of body centre of gravity (P < 0.05-0.01). It is concluded that during a stretch-shortening cycle cooling alters the EMG-activity of agonist and antagonist muscles on a contradictory manner and results in an earlier peak EMG-activity. Therefore, alterations in motor unit recruitment could be responsible for the prolonged muscle contraction and decreased force production on account of cooling.

Adult↗

PubMed1996

Important determinants of anaerobic running performance in male athletes and non-athletes.

The purpose of this study was to investigate the importance of selected metabolic and neuromuscular determinants as predictors of anaerobic running performance. The subjects were male 400-m runners (n = 21), middle- (n = 8) and long-distance runners (n = 11), power athletes (n = 14) and physically active men (n = 34). Maximal power (Pmax), peak blood lactate concentration (peak BLa), power at 10 mM blood lactate level (P10mM), height (CMJrest) and percentage decrease (CMJdecrease) of the counter-movement jump were determined by the maximal anaerobic running test (MART). In addition, maximal oxygen uptake (VO2max) was determined on a treadmill and maximal running velocity (V30m) was measured by the 30-m speed test on a track. Stepwise regression analysis revealed that V30m, P10mM and peak BLa accounted for 92% (P < 0.001) of the variation in Pmax. Regression analysis showed also that V30m, P10mM and delta P (the difference between Pmax and VO2max) were the most important determinants of the 400-m run on a track within a homogeneous group of 400-m runners. The middle-distance and 400-m runners had higher Pmax and P10mM than the long-distance and control group (p < 0.05). The 400-m runners had superior V30m and delta P than the other groups. Furthermore, the 400-m runners and power athletes had higher peak BLa than the long-distance and control group (p < 0.05). The present findings showed that V30m, P10mM and peak BLa determined by the 30-m speed test and the MART were the most important components of anaerobic work capacity. These determinants could be used to explain the differences in anaerobic work capacity between various sport groups as well as between different athletes.

Adult↗

PubMed1996

Reliability and validity of the maximal anaerobic running test.

Physically active men (n = 13) twice performed the Maximal Anaerobic Running Test (MART) on a treadmill and once the Wingate Anaerobic Test (WAnT) on a cycle ergometer. The MART consisted of n 20-s runs with 100-s recovery between the runs. The speed of the first run was 14.6 km.h-1 and the inclination 4 degrees. Thereafter, the speed was increased by 1.37 km.h-1 every run until exhaustion. During all tests oxygen uptake was measured breath-by-breath and blood samples were taken from the fingertip 40s after each run to determine the lactate concentration (BLa). Power at submaximal BLa levels and maximal power (P5mM, P10mM and Pmax, respectively) were calculated and P was expressed as the oxygen demand of running according to the American College of Sports Medicine equation. In the MART the Pmax was 108 ml.kg-1.min-1 and peak BLa was 15.6 mM. The reliability for the power indices in the MART were as follows: r = 0.92 (p < 0.001) for Pmax r = 0.80 (p < 0.001) for P10mM and r = 0.67 (p = 0.01) for P5mM. The average contribution of anaerobic energy expenditure was calculated to be 68% but it ranged from 64% to 72% during the MART. Although four out of seven of the correlations between the corresponding variables of the MART and WAnT were significant (0.52 < r < 0.59) they were not high. It is concluded that the anaerobic energy production is high in the MART, the test is reliable, and that the treadmill and cycle ergometer test measure slightly different qualities.

Exercise Test↗

PubMed1996

Effect of inclination on the results of the maximal anaerobic running test.

This study investigated the effect of treadmill inclination on the maximal anaerobic running test (MART). Ten male subjects ran a 20-m speed test on a track to determine the maximal running velocity (V20m) and performed three MARTs at the grades of 1 degree, 4 degrees and 7 degrees in a random order. Each MART included n 20-s sprints at gradually increased velocity and counter-movement jumps (CMJ) which were performed before and after the exhausting sprints. At each grade, the power (oxygen demand) of the sprints was determined by extrapolating the individual steady state oxygen uptake of three submaximal running velocities measured separately at the corresponding grades. Maximal power (Pmax), power at 10mM (P10mM) and 5 mM (P5mM) blood lactate levels as well as peak blood lactate concentration (peak BLa) were determined at each MART. The Pmax increased from 94.1 +/- 8.8 and 110.0 +/- 10.2 to 119.5 +/- 8.0 ml.kg-1.min-1 when the treadmill inclination increased from 1 degree and 4 degrees to 7 degrees, respectively (p < 0.001). P10mM and P5mM also increased with the inclination (p < 0.001). Correlation coefficients of the Pmax with CMJrest and V20m were 0.77 and 0.69 at the grade of 1 degree, 0.75 and 0.59 at the grade of 4 degrees, and 0.62 and 0.42 at the grade of 7 degrees, respectively. The increased peak BLa (p < 0.01) with the treadmill inclination suggests that lactic capacity was not completely used at the grades of 1 degree and 4 degrees. In conclusion, the maximal power increased with the grade of uphill running in the MART. Furthermore, the present results suggest that the importance of force and velocity components of the neuromuscular system decreased and the importance of metabolic component increased with the increased grade of the uphill running.

Adult↗

PubMed1996

Comparison of three maximal anaerobic running test protocols in marathon runners, middle-distance runners and sprinters.

Three modifications of the maximal anaerobic running test (MART) were compared in sprinters (Spr, n = 5), middle-distance runners (Mid, n = 5) and marathon runners (Mar, n = 6). The MART1, MART3 and MART5 consisted of n sets of 1.20-s, 3.20-s and 5.20-s runs, respectively, on a treadmill with 40-s recovery between the runs and 100-s recovery between the sets. In each MART the velocity of the first set of runs was 3.0 m.s-1 and the slope 4 degrees. Thereafter, the velocity was gradually increased by 0.38 m.s-1 for each consecutive set until exhaustion. After each set and after exhaustion fingertip blood samples were taken to determine lactate concentration and three counter-movement jumps (CMJ) were performed. Maximal (Pmax) and submaximal (P4mM) running power in each MART was expressed as the oxygen demand (ml.kg-1.min-1) of the runs. In MART1, Mar had a significantly lower Pmax than Mid or Spr (mean +/- SD; 97.8 +/- 5.4 vs. 121.0 +/- 4.4 vs. 119.2 +/- 5.4 ml.kg-1.min-1), while in MART3 the groups did not differ significantly, and the sprinters were unable to perform MART5. Mar, Mid and Spr attained the lower Pmax the more runs per set in MART (p < 0.01). Mar had the higher peak blood lactate the more runs each set consisted of (p < 0.001). In Mid and Spr, the peak blood lactate did not differ significantly between the MARTs but was significantly higher than the corresponding peak blood lactate of the marathon runners. Pmax in MART1 correlated positively with maximal 20-m sprinting speed on a track and with CMJ height (p < 0.001, n = 16) but negatively with VO2 max (p < 0.001, n = 16) while in MART3 no significant correlations were found. It was concluded that the n.1.20-s protocol should be used to measure the maximal anaerobic power of all runners. However, in long-distance runners more runs per set may be needed to evaluate their anaerobic capacity.

Adult↗