The brain direct current potential (DC) is regarded in physiology and medicine as an integrated s... more The brain direct current potential (DC) is regarded in physiology and medicine as an integrated system marker for the assessment of the body's functional state, stress resistance, and adaptation capacity [1]. Researchers emphasize that the DC is highly sensitive to short-term and long-term adaptational changes in the body in response to external factors [2]. This research aims to study the specificity of DC changes with different training types in recreational runners.
The study was planned to study whether acute or a 7-day Bergenia intake has any effects on endura... more The study was planned to study whether acute or a 7-day Bergenia intake has any effects on endurance exercise capacity or muscle strength. The study included two experimental designs: to investigate the acute effects and the effect of 7-day use of Bergenia. The study was double blind placebo controlled crossover study. Thirty physically active men were divided into three groups who ingested one, two or four capsules containing either isomalt (placebo) or Bergenia extract (100 mg) plus isomalt. The order of the placebo and Bergenia tests was randomized so that half of each group had first placebo and then Bergenia tests and the other half had the opposite order. The endurance test was maximal incremental cycling test in which maximal power, maximal blood lactate, maximal heart rate, maximal ventilation, VO2max as well as RPE and glucose concentration at exhaustion were determined. The strength tests were maximal isometric leg press and vertical counter-movement jump. The results of the present study showed that the Bergenia supplementation with the current doses of 100–400 mg does not have almost any acute or a 7-day usage effect on endurance and maximal force characteristics in physically active men. Bergenia supplementation did not cause any negative effects on the present subjects either. In the previous studies it was shown that supplementation of animals with the extract from fermented leaves of Bergenia enhanced the maximum swimming capacity of mice. We may make a hypothesis that probably other dose ranges and prolongation of supplementation time would be more correct for future human experiments.201
This study investigated neuromuscular characteristics and fatigue during 10 km running (10 K) per... more 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.
The aim of the present study was to investigate the time course of aerobic and anaerobic energy y... more The aim of the present study was to investigate the time course of aerobic and anaerobic energy yield during supramaximal exhaustive running on the treadmill in sprint and endurance athletes. In addition, the relationships between O2 deficit, excess post-exercise O2 consumption (EPOC) and peak post-exercise blood lactate concentration (peak BLa) values were examined, Oxygen uptake during the exhaustive run and 15 min recovery period was measured using a breath-by-breath method. The accumulated O2 deficit was calculated by an extrapolation procedure. Total running time was the same for eight male sprint runners (49.5 +/- 6.0s) and for six male endurance athletes (49.4 +/- 5.3 s). The sprint group had significantly higher O2 deficit (p < 0.01) during the run as well as higher peak BLa (p < 0.05) and EPOC (p < 0.01) after the run than the endurance group. The relative contribution of anaerobic energy yield decreased from 80% to 60% during the first 15 s of the exhaustive run in both groups. The VO2 peaked and was almost unchanged from 25th to 40th s of the run in both groups, although only 79% of their VO2max was attained. The relative contribution of aerobic energy yield was significantly higher (p < 0.05) in the endurance (54-63%) than in the sprint group (43-47%) during the second half of the run. No correlation was found between the O2 deficit and EPOC but peak BLa correlated significantly (p < 0.05) with the O2 deficit (r = 0.53) and EPOC (r = 0.53). In conclusion, the energy release of the sprint and endurance athletes was different only during the second half of the exhaustive supramaximal run, when the sprinters used more the anaerobic and endurance athletes aerobic pathways for energy production.
This study investigated fatigue-induced changes in neuromuscular and stride characteristics durin... more This study investigated fatigue-induced changes in neuromuscular and stride characteristics during and immediately after the 5-km running time trial. Eighteen well-trained male distance runners performed a maximal 20-m sprint test and maximal voluntary contraction (MVC) in a leg press machine before and immediately after the 5-km running time trial. In all the tests the EMG of five lower limb muscles was measured. The results of the present study showed that muscle fatigue measured in maximal exercises like 20-m sprint and MVC are not related to the fatigue induced changes during the 5-km time trial. The fatigue in the 20-m sprint test was related to the maximal 20-m pretest velocity (r=0.58, p<0.05), but the velocity loss during the 5-km time trial was inversely related to 5-km performance (r= - 0.60, p<0.05) and training volume (r= - 0.58, p<0.05). It was concluded that the fatigue in 5-km running measured pre- and postexercise at maximal effort is more related to sprint ...
Fatigue during the 400-m sprint was studied by measuring muscle ATP, creatine phosphate (CP), lac... more Fatigue during the 400-m sprint was studied by measuring muscle ATP, creatine phosphate (CP), lactate (M-La), and blood lactate (B-La) in six male runners before and after four experimental sprints (100, 200, 300, and 400 m). During the first 100 m, muscle CP decreased from 15.8 +/- 1.7 to 8.3 +/- 0.3 mmol/kg while M-La increased to 3.6 +/- 0.4 mmol/kg. After 200 m the CP had decreased to 6.5 +/- 0.5 mmol/kg and M-La had increased to 8.3 +/- 1.1 mmol/kg. At the end of the 400 meters, ATP and CP concentrations had decreased by 27% and 89%, respectively, and M-La had increased to 17.3 +/- 0.9 mmol/kg. It was concluded that after 200 m the speed of running decreased, although CP was not depleted and lactate concentration was not at maximum level. Complete fatigue occurred when CP stores were depleted and B-La and M-La attained an individual maximum.
This study examined the effects of endurance exercise on nocturnal autonomic modulation. Nocturna... more This study examined the effects of endurance exercise on nocturnal autonomic modulation. Nocturnal R-R intervals were collected after a rest day, after a moderate endurance exercise and after a marathon run in ten healthy, physically active men. Heart rate variability (HRV) was analyzed as a continuous four-hour period starting 30 min after going to bed for sleep. In relation to average nocturnal heart rate after rest day, increases to 109+/-6% and 130+/-11% of baseline were found after moderate endurance exercise and marathon, respectively. Standard deviation of R-R intervals decreased to 90+/-9% and 64+/-10%, root-mean-square of differences between adjacent R-R intervals to 87+/-10% and 55+/-16%, and high frequency power to 77+/-19% and 34+/-19% of baseline after moderate endurance exercise and marathon, respectively. Also nocturnal low frequency power decreased to 56+/-26% of baseline after the marathon. Changes in nocturnal heart rate and HRV suggest prolonged dose-response effe...
Physiological Stress of Competing and Training in Figure Skating Esa Hynynen1, Ville Vesterinen1,... more Physiological Stress of Competing and Training in Figure Skating Esa Hynynen1, Ville Vesterinen1, Tommi Sipari1, Laura Tast2, Ari Nummela1 1 KIHU – Research Institute for Olympic Sports, Jyvaskyla, Finland 2 Finnish Figure Skating Association, Helsinki, Finland Despite the merits of many studies on biomechanics and injuries in figure skating, physiological demands of figure skating remain unclear. PURPOSE: This study was made to investigate the physiological stress of training and competing in figure skaters. METHODS: Five men and five women of the national team of Finland participated in this study. Heart rate was recorded during the short program and free skating competition. Fingertip blood samples were collected immediately after the program sessions to analyze blood lactate concentrations. The athletes also rated their perceived exertion (0-10) after program sessions. In addition, the same measurements were done in two training sessions (technique and program) in two men and two women. RESULTS: Figure skaters had higher blood lactate concentration after free skating when compared to the short program (12.0 ± 2.2 mM vs. 10.7 ± 2.2 mM, P < 0.05, respectively). They also rated their perceived exertion higher after free skating when compared to the short program (8.2 ± 1.1 vs. 6.4 ± 1.4, P < 0.01). No differences were found in the heart rate responses to competitions between the short program and free skating. Blood lactate concentrations were higher in competitions when compared to the technique training sessions (1.3 ± 2.2 mM, P < 0.01) and program training sessions (7.1 ± 2.6 mM, P < 0.05). The perceived exertion in technique training session was rated lower (5.0 ± 1.6) than in the competitions (P < 0.05) and in program training sessions (6.5 ± 1.7, P < 0.05). Also the average heart rate was higher during the competition (188 ± 7 bpm) than in technique training sessions (132 ± 20 bpm, P < 0.05) and program training sessions (175 ± 8 bpm, P < 0.05). CONCLUSION: The present findings of high heart rate and blood lactate concentrations suggest that the physiological stress is high during the competitions and during the program training. The longer duration of the free skating may explain the higher blood lactate concentrations and perceived exertion in comparison to the short program. The competition situation seems to accentuate the sympathetic activity as suggested by higher heart rate during program in competition than in training.
Training load (TL) in constant velocity exercises depends on both exercise intensity and duration... more Training load (TL) in constant velocity exercises depends on both exercise intensity and duration and in interval exercises the recovery time between the running bouts is also an important factor. Furthermore, individual training history and performance profile affect TL. Based on exercise intensity, duration and individual performance profile a new TL and TL recovery model was developed for running. PURPOSE: To test a new model to determine TL and recovery in constant velocity and interval exercises in running. METHODS: Seventeen untrained men and women performed five different constant load exercise (3.5 km at 50%, 63% and 74% of vVO2max, 7 km at 50% and 63% at vVO2max) and 13 male recreational runners performed three different constant load exercises (3 km at 60% and 85% of vVO2max and 14 km at 60% of vVO2max) and three different interval exercises (12x250m at 85% and 105% of vVO2max and 6x500m at 85% of vVO2max) on a treadmill. In order to test the validity of the new TL model, Excess Post-exercise Oxygen Consumption (EPOC), heart rate, blood lactate concentration (BLa) and rating of perceived exertion (RPE) were measured from all the exercises. Furthermore, endurance performance characteristics were measured by a graded treadmill test and a questionnaire for training history and performance profile was filled by the subjects. RESULTS: The new TL model ranked the analyzed exercises in the same order as EPOC, RPE and BLa in both untrained subjects and recreational runners. When all the subjects and exercise data were pooled, a significant correlation (P < 0.001) was observed between the calculated TL and EPOC, RPE and BLa (r = 0.56, 0.60 and 0.66, respectively). Similar correlations were also observed when untrained subjects and recreational runners were analyzed separately. Significant correlations between TL and EPOC, RPE and BLa were also observed when both constant load and interval exercises were pooled in recreational runners (r = 0.6 – 0.8, P < 0.001). CONCLUSION: The results of the present study showed that the new TL model can be used to compare training load of different constant load and interval exercises in subjects with different training history and performance profile. More study is needed to assess whether the new TL model is useful for monitoring the training in running.
The brain direct current potential (DC) is regarded in physiology and medicine as an integrated s... more The brain direct current potential (DC) is regarded in physiology and medicine as an integrated system marker for the assessment of the body's functional state, stress resistance, and adaptation capacity [1]. Researchers emphasize that the DC is highly sensitive to short-term and long-term adaptational changes in the body in response to external factors [2]. This research aims to study the specificity of DC changes with different training types in recreational runners.
The study was planned to study whether acute or a 7-day Bergenia intake has any effects on endura... more The study was planned to study whether acute or a 7-day Bergenia intake has any effects on endurance exercise capacity or muscle strength. The study included two experimental designs: to investigate the acute effects and the effect of 7-day use of Bergenia. The study was double blind placebo controlled crossover study. Thirty physically active men were divided into three groups who ingested one, two or four capsules containing either isomalt (placebo) or Bergenia extract (100 mg) plus isomalt. The order of the placebo and Bergenia tests was randomized so that half of each group had first placebo and then Bergenia tests and the other half had the opposite order. The endurance test was maximal incremental cycling test in which maximal power, maximal blood lactate, maximal heart rate, maximal ventilation, VO2max as well as RPE and glucose concentration at exhaustion were determined. The strength tests were maximal isometric leg press and vertical counter-movement jump. The results of the present study showed that the Bergenia supplementation with the current doses of 100–400 mg does not have almost any acute or a 7-day usage effect on endurance and maximal force characteristics in physically active men. Bergenia supplementation did not cause any negative effects on the present subjects either. In the previous studies it was shown that supplementation of animals with the extract from fermented leaves of Bergenia enhanced the maximum swimming capacity of mice. We may make a hypothesis that probably other dose ranges and prolongation of supplementation time would be more correct for future human experiments.201
This study investigated neuromuscular characteristics and fatigue during 10 km running (10 K) per... more 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&lt;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&lt;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&lt;0.05) mean CT of CVLs than LC. A significant correlation (r = -0.56, p&lt;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&lt;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&lt;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.
The aim of the present study was to investigate the time course of aerobic and anaerobic energy y... more The aim of the present study was to investigate the time course of aerobic and anaerobic energy yield during supramaximal exhaustive running on the treadmill in sprint and endurance athletes. In addition, the relationships between O2 deficit, excess post-exercise O2 consumption (EPOC) and peak post-exercise blood lactate concentration (peak BLa) values were examined, Oxygen uptake during the exhaustive run and 15 min recovery period was measured using a breath-by-breath method. The accumulated O2 deficit was calculated by an extrapolation procedure. Total running time was the same for eight male sprint runners (49.5 +/- 6.0s) and for six male endurance athletes (49.4 +/- 5.3 s). The sprint group had significantly higher O2 deficit (p &lt; 0.01) during the run as well as higher peak BLa (p &lt; 0.05) and EPOC (p &lt; 0.01) after the run than the endurance group. The relative contribution of anaerobic energy yield decreased from 80% to 60% during the first 15 s of the exhaustive run in both groups. The VO2 peaked and was almost unchanged from 25th to 40th s of the run in both groups, although only 79% of their VO2max was attained. The relative contribution of aerobic energy yield was significantly higher (p &lt; 0.05) in the endurance (54-63%) than in the sprint group (43-47%) during the second half of the run. No correlation was found between the O2 deficit and EPOC but peak BLa correlated significantly (p &lt; 0.05) with the O2 deficit (r = 0.53) and EPOC (r = 0.53). In conclusion, the energy release of the sprint and endurance athletes was different only during the second half of the exhaustive supramaximal run, when the sprinters used more the anaerobic and endurance athletes aerobic pathways for energy production.
This study investigated fatigue-induced changes in neuromuscular and stride characteristics durin... more This study investigated fatigue-induced changes in neuromuscular and stride characteristics during and immediately after the 5-km running time trial. Eighteen well-trained male distance runners performed a maximal 20-m sprint test and maximal voluntary contraction (MVC) in a leg press machine before and immediately after the 5-km running time trial. In all the tests the EMG of five lower limb muscles was measured. The results of the present study showed that muscle fatigue measured in maximal exercises like 20-m sprint and MVC are not related to the fatigue induced changes during the 5-km time trial. The fatigue in the 20-m sprint test was related to the maximal 20-m pretest velocity (r=0.58, p<0.05), but the velocity loss during the 5-km time trial was inversely related to 5-km performance (r= - 0.60, p<0.05) and training volume (r= - 0.58, p<0.05). It was concluded that the fatigue in 5-km running measured pre- and postexercise at maximal effort is more related to sprint ...
Fatigue during the 400-m sprint was studied by measuring muscle ATP, creatine phosphate (CP), lac... more Fatigue during the 400-m sprint was studied by measuring muscle ATP, creatine phosphate (CP), lactate (M-La), and blood lactate (B-La) in six male runners before and after four experimental sprints (100, 200, 300, and 400 m). During the first 100 m, muscle CP decreased from 15.8 +/- 1.7 to 8.3 +/- 0.3 mmol/kg while M-La increased to 3.6 +/- 0.4 mmol/kg. After 200 m the CP had decreased to 6.5 +/- 0.5 mmol/kg and M-La had increased to 8.3 +/- 1.1 mmol/kg. At the end of the 400 meters, ATP and CP concentrations had decreased by 27% and 89%, respectively, and M-La had increased to 17.3 +/- 0.9 mmol/kg. It was concluded that after 200 m the speed of running decreased, although CP was not depleted and lactate concentration was not at maximum level. Complete fatigue occurred when CP stores were depleted and B-La and M-La attained an individual maximum.
This study examined the effects of endurance exercise on nocturnal autonomic modulation. Nocturna... more This study examined the effects of endurance exercise on nocturnal autonomic modulation. Nocturnal R-R intervals were collected after a rest day, after a moderate endurance exercise and after a marathon run in ten healthy, physically active men. Heart rate variability (HRV) was analyzed as a continuous four-hour period starting 30 min after going to bed for sleep. In relation to average nocturnal heart rate after rest day, increases to 109+/-6% and 130+/-11% of baseline were found after moderate endurance exercise and marathon, respectively. Standard deviation of R-R intervals decreased to 90+/-9% and 64+/-10%, root-mean-square of differences between adjacent R-R intervals to 87+/-10% and 55+/-16%, and high frequency power to 77+/-19% and 34+/-19% of baseline after moderate endurance exercise and marathon, respectively. Also nocturnal low frequency power decreased to 56+/-26% of baseline after the marathon. Changes in nocturnal heart rate and HRV suggest prolonged dose-response effe...
Physiological Stress of Competing and Training in Figure Skating Esa Hynynen1, Ville Vesterinen1,... more Physiological Stress of Competing and Training in Figure Skating Esa Hynynen1, Ville Vesterinen1, Tommi Sipari1, Laura Tast2, Ari Nummela1 1 KIHU – Research Institute for Olympic Sports, Jyvaskyla, Finland 2 Finnish Figure Skating Association, Helsinki, Finland Despite the merits of many studies on biomechanics and injuries in figure skating, physiological demands of figure skating remain unclear. PURPOSE: This study was made to investigate the physiological stress of training and competing in figure skaters. METHODS: Five men and five women of the national team of Finland participated in this study. Heart rate was recorded during the short program and free skating competition. Fingertip blood samples were collected immediately after the program sessions to analyze blood lactate concentrations. The athletes also rated their perceived exertion (0-10) after program sessions. In addition, the same measurements were done in two training sessions (technique and program) in two men and two women. RESULTS: Figure skaters had higher blood lactate concentration after free skating when compared to the short program (12.0 ± 2.2 mM vs. 10.7 ± 2.2 mM, P < 0.05, respectively). They also rated their perceived exertion higher after free skating when compared to the short program (8.2 ± 1.1 vs. 6.4 ± 1.4, P < 0.01). No differences were found in the heart rate responses to competitions between the short program and free skating. Blood lactate concentrations were higher in competitions when compared to the technique training sessions (1.3 ± 2.2 mM, P < 0.01) and program training sessions (7.1 ± 2.6 mM, P < 0.05). The perceived exertion in technique training session was rated lower (5.0 ± 1.6) than in the competitions (P < 0.05) and in program training sessions (6.5 ± 1.7, P < 0.05). Also the average heart rate was higher during the competition (188 ± 7 bpm) than in technique training sessions (132 ± 20 bpm, P < 0.05) and program training sessions (175 ± 8 bpm, P < 0.05). CONCLUSION: The present findings of high heart rate and blood lactate concentrations suggest that the physiological stress is high during the competitions and during the program training. The longer duration of the free skating may explain the higher blood lactate concentrations and perceived exertion in comparison to the short program. The competition situation seems to accentuate the sympathetic activity as suggested by higher heart rate during program in competition than in training.
Training load (TL) in constant velocity exercises depends on both exercise intensity and duration... more Training load (TL) in constant velocity exercises depends on both exercise intensity and duration and in interval exercises the recovery time between the running bouts is also an important factor. Furthermore, individual training history and performance profile affect TL. Based on exercise intensity, duration and individual performance profile a new TL and TL recovery model was developed for running. PURPOSE: To test a new model to determine TL and recovery in constant velocity and interval exercises in running. METHODS: Seventeen untrained men and women performed five different constant load exercise (3.5 km at 50%, 63% and 74% of vVO2max, 7 km at 50% and 63% at vVO2max) and 13 male recreational runners performed three different constant load exercises (3 km at 60% and 85% of vVO2max and 14 km at 60% of vVO2max) and three different interval exercises (12x250m at 85% and 105% of vVO2max and 6x500m at 85% of vVO2max) on a treadmill. In order to test the validity of the new TL model, Excess Post-exercise Oxygen Consumption (EPOC), heart rate, blood lactate concentration (BLa) and rating of perceived exertion (RPE) were measured from all the exercises. Furthermore, endurance performance characteristics were measured by a graded treadmill test and a questionnaire for training history and performance profile was filled by the subjects. RESULTS: The new TL model ranked the analyzed exercises in the same order as EPOC, RPE and BLa in both untrained subjects and recreational runners. When all the subjects and exercise data were pooled, a significant correlation (P < 0.001) was observed between the calculated TL and EPOC, RPE and BLa (r = 0.56, 0.60 and 0.66, respectively). Similar correlations were also observed when untrained subjects and recreational runners were analyzed separately. Significant correlations between TL and EPOC, RPE and BLa were also observed when both constant load and interval exercises were pooled in recreational runners (r = 0.6 – 0.8, P < 0.001). CONCLUSION: The results of the present study showed that the new TL model can be used to compare training load of different constant load and interval exercises in subjects with different training history and performance profile. More study is needed to assess whether the new TL model is useful for monitoring the training in running.
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