| 1. |
- Karlsson, Håkan K R, et al.
(author)
-
Branched-chain amino acids increase p70S6k phosphorylation in human skeletal muscle after resistance exercise.
- 2004
-
In: American Journal of Physiology. Endocrinology and Metabolism. - : American Physiological Society. - 0193-1849 .- 1522-1555. ; 287:1, s. E1-7
-
Journal article (peer-reviewed)abstract
- The aim of the study was to investigate the effect of resistance exercise alone or in combination with oral intake of branched-chain amino acids (BCAA) on phosphorylation of the 70-kDa S6 protein kinase (p70(S6k)) and mitogen-activated protein kinase (MAPK), extracellular signal-regulated kinase (ERK1/2), and p38 MAPK in skeletal muscle. Seven male subjects performed one session of quadriceps muscle resistance training (4 x 10 repetitions at 80% of one repetition maximum) on two occasions. In a randomized order, double-blind, crossover test, subjects ingested a solution of BCAA or placebo during and after exercise. Ingestion of BCAA increased plasma concentrations of isoleucine, leucine, and valine during exercise and throughout recovery after exercise (2 h postexercise), whereas no change was noted after the placebo trial. Resistance exercise led to a robust increase in p70(S6k) phosphorylation at Ser(424) and/or Thr(421), which persisted 1 and 2 h after exercise. BCAA ingestion further enhanced p70(S6k) phosphorylation 3.5-fold during recovery. p70(S6k) phosphorylation at Thr(389) was unaltered directly after resistance exercise. However, during recovery, Thr(389) phosphorylation was profoundly increased, but only during the BCAA trial. Furthermore, phosphorylation of the ribosomal protein S6 was also increased in the recovery period only during the BCAA trial. Exercise led to a marked increase in ERK1/2 and p38 MAPK phosphorylation, which was completely suppressed upon recovery and unaltered by BCAA. In conclusion, BCAA, ingested during and after resistance exercise, mediate signal transduction through p70(S6k) in skeletal muscle.
|
|
| 2. |
- Ekblom, Björn, et al.
(author)
-
Aktivt liv : vetenskap & praktik
- 2000
-
Book (pop. science, debate, etc.)abstract
- En halvtimmes promenad varje dag ger oss människor den bästa medicin som existerar. Vi blir både friskare, lever längre och får mer livskvalitet genom att röra oss lite varje dag. Aktivt liv är en gedigen faktabok som täcker den viktigaste och mest aktuella forskningen inom området idrott & hälsa. Boken rymmer en enorm mängd användbar kunskap, tips och idéer för dig som är intresserad av området. Aktivt liv fungerade utmärkt som fakta- och idébank inför rörelseåret 2001 - Sätt Sverige i rörelse.
|
|
| 3. |
- Fredriksson, Mårten, et al.
(author)
-
Testmanual funktionella tester : allmänna testförberedelser, chins, dips, vertikala situps, hängande raka benlyft, vertikalhopp, Harres test, Beep-testet
- 2003
-
Reports (other academic/artistic)abstract
- Ur förordet: I din hand håller du ”Testmanual - funktionella tester”. Den är ett resultat av arbetsinsatser gjorda under ett kursmoment i den fristående kursen ”Specialidrott med inriktning mot träning och prestation” (41-60p) vid Idrottshögskolan i Stockholm (år 2000-2001). Ett av delmålen i kursmomentet var att i detalj analysera mätförfarandet i ett antal etablerade funktionella tester och med utgångspunkt från denna analys sammanställa en testmanual. Testerna mäter flera delkapaciteter i prestationsförmågan som t ex styrka, uthållighet och motorik. Författarteamet nedan tackar representanter för Sveriges Olympiska Kommitté, Riksidrottsförbundet och EIC Bosön för väsentliga bidrag i framtagandet av detta material.Innehåll:ALLMÄNNA TESTFÖRBEREDELSERÅtgärder före test Personuppgifter, Hälsodeklaration, TestinformationAllmän checklistaSTYRKETESTER - STYRKA & UTHÅLLIGHET I BÅL OCH ÖVERKROPPIntroduktion - Golden FourChinsDipsVertikala sit-upsHängande raka benlyftSTYRKETESTER - EXPLOSIV BENMUSKELSTYRKAIntroduktion – VertikalhoppSquat Jump (SJ)Counter Movement Jump (CMJ)KOORDINATIONHarresUTHÅLLIGHETBeep-test / shuttle-run test
|
|
| 4. |
|
|
| 5. |
- Nilsson, Erland, et al.
(author)
-
Load Distribution with the Proximity Congestion Awareness in a Network on Chip
- 2003
-
In: Design, Automation And Test In Europe Conference And Exhibition, Proceedings. - LOS ALAMITOS, USA : IEEE COMPUTER SOC. - 0769518702 ; , s. 1126-1127
-
Conference paper (peer-reviewed)abstract
- In Networks on Chip, NoC, very low cost and high performance switches will be of critical importance. For a regular two-dimensional NoC we propose a very simple, memoryless switch. In case of congestion, packets are emitted in a non-ideal direction, also called deflective routing. To increase the maximum tolerable load of the network, we propose a Proximity Congestion Awareness, PCA, technique, where switches use load information of neighbouring switches, called stress values, for their own switching decisions, thus avoiding congested areas. We present simulation results with random traffic which show that the PCA technique can increase the maximum traffic load by a factor of over 20.
|
|
| 6. |
- Nilsson, Erland, et al.
(author)
-
Reducing Power and Latency in 2-D Mesh NoCs using Globally Pseudochronous Locally Synchronous Clocking
- 2004
-
In: International Conference On Hardware/Software Codesign And System Synthesis. - New York, USA : ASSOC COMPUTING MACHINERY. - 1581139373 ; , s. 176-181
-
Conference paper (peer-reviewed)abstract
- One of the main problems when designing large ASICs today is to distribute a low power synchronous clock over the whole chip and a lot of remedies to this problem has been proposed over the years. For Networks-on-Chip (NoC), where computational Resources are organised in a 2-D mesh connected together through Switches in an on-chip interconnection network, another possibility exists: Globally Pseudochronous Locally Synchronous clock distribution. In this paper, we present a clocking scheme for NoCs that we call Globally Pseudochronous Locally Synchronous, in which we distribute a clock with a constant phase difference between he switches. As a consequence of the phase difference, some paths along the NoC switch network become faster than the others. We call these paths Data Motorways. By adapting the switching policy in the switches to prefer data to use the motorways, we show that the latency within the network is reduced with up to 40% compared to a synchronous reference case. The phase difference between the resources also makes the circuit more tolerant to clock skew. It also distributes the current peaks more evenly across the clock period, which lead to a reduction in peak power, which in turn further reduces the clock skew and the jitter in the clock network.
|
|
| 7. |
- Nilsson, Johnny E, et al.
(author)
-
Effects of 20-s and 180-s double poling interval training in cross-country skiers
- 2004
-
In: European Journal of Applied Physiology. - : Springer Science and Business Media LLC. - 1439-6319 .- 1439-6327. ; 92:1/2, s. 121-127
-
Journal article (peer-reviewed)abstract
- The purpose of this study was to investigate the effect of upper body 20-s or 180-s interval training, using a double poling ergometer, on upper body power output and selected physiological and biomechanical parameters in cross-country skiers. Twenty (12 male, 8 female) well-trained cross-country skiers took part. Two intervention groups, a 20-s interval training group (IT20; n=6) and a 180-s interval training group (IT180; n=7), underwent training three times a week for 6 weeks on a double poling ergometer. A third group served as a control (CON; n=7) and followed the same training program as the IT20 and IT180 groups without the double poling ergometer interval training. The IT20 and IT180 groups significantly (P<0.05) increased both peak and mean power in a 30-s test and mean power in a 6-min test after double poling training. There was a significant improvement in work efficiency in both IT20 and IT180 (P<0.05) and, in IT180, a significant reduction (P<0.05) in blood lactate concentration at given sub-maximal workloads. VO(2peak) increased significantly during double poling in IT180 ( P<0.05) only. VO(2max) did not change significantly in either group. There were no significant changes in any of the test variables in CON. In conclusion, this study shows that 6 weeks of 20-s or 180-s double poling interval training, three times a week, significantly increases power output in both 30-s and 6-min tests, as well as in selected physiological and biomechanical parameters in well-trained cross-country skiers.
|
|
| 8. |
- Nilsson, Johnny, et al.
(author)
-
Effects of speed on temporal patterns in classical style and freestyle cross-country skiing.
- 2004
-
In: Sports biomechanics / International Society of Biomechanics in Sports. - : Informa UK Limited. - 1476-3141. ; 3:1, s. 85-107
-
Journal article (peer-reviewed)abstract
- The purpose was to study the adaptation to speed in the temporal patterns of the movement cycle and determine any differences in velocity, cycle rate and cycle length at the maximum speed level in the different classical style and freestyle cross-country skiing techniques. Eight skilled male cross-country skiers were filmed with a digital video camera in the sagittal plane while skiing on a flat cross-country ski track. The skiers performed three classical style techniques the diagonal stride, kick double poling and the double poling technique and four freestyle techniques paddle dance (gear 2), double dance (gear 3), single dance (gear 4) and combiskate (gear 5) at four different self-selected speed levels slow, medium, fast and their maximum. Cycle duration, cycle rate, cycle length, and relative and absolute cycle phase duration of the different techniques at the different speed levels were analysed by means of a video analysis system. The cycle rate in all tested classical and freestyle techniques was found to increase significantly (p < .01) with speed from slow to maximum. Simultaneously, there was a significant decrease in the absolute phase durations of all the investigated skiing techniques. A minor, not significant, change in cycle length, and the significant increase in cycle rate with speed showed that the classical and freestyle cross-country skiing styles are dependent, to a large extent, on an increase in cycle rate for speed adaptation. A striking finding was the constant relative phase duration with speed, which indicates a simplified neural control of the speed adaptation in both cross-country skiing styles. For the practitioner, the knowledge about the importance of increasing cycle frequency rather than cycle length in the speed adaptation can be used to optimise a rapid increase in speed. The knowledge about the decrease in absolute phase duration, especially the thrust phase duration, points to the need for strength and technique training to enable force production at a high cycle rate and skiing speed. The knowledge that the relative phase duration stays constant with speed may be used to simplify the learning of the different cross-country skiing techniques.
|
|
| 9. |
- Nilsson, Johnny, et al.
(author)
-
Knee angular displacement and extensor muscle activity in telemark skiing and in ski-specific strength exercises.
- 2004
-
In: Journal of Sports Sciences. - 0264-0414 .- 1466-447X. ; 22:4, s. 357-64
-
Journal article (peer-reviewed)abstract
- Much of the training of competitive telemark skiers is performed as dry-land exercises. The specificity of these exercises is important for optimizing the training effect. Our aim here was to study the activation of the knee extensor musculature and knee angular displacement during competitive telemark skiing and during dry-land strength training exercises to determine the specificity of the latter. Specificity was analysed with respect to angular amplitude, angular velocity, muscle action and electromyographic (EMG) activity. Five male telemark skiers of national and international standard volunteered to participate in the study, which consisted of two parts: (1) skiing a telemark ski course and (2) specific dry-land strength training exercises for telemark skiing (telemark jumps and barbell squats). The angular displacement of the right knee joint was recorded with an electrogoniometer. A tape pressure sensor was used to measure pressure between the sole of the foot and the bottom of the right ski boot. Electromyographic activity in the right vastus lateralis was recorded with surface electrodes. The EMG activity recorded during maximum countermovement jumps was used to normalize the EMG activity during telemark skiing, telemark jumps and barbell squats. The results showed that knee angular displacement during telemark skiing and dry-land telemark jumps had four distinct phases: a flexion (F1) and extension (E1) phase during the thrust phase of the outside ski/leg in the turn/jump and a flexion (F2) and extension (E2) phase when the leg was on the inside of the turn/jump. The vastus lateralis muscle was activated during F1 and E1 in the thrust phase during telemark skiing and telemark jumps. The overall net knee angular amplitude was significantly greater (P < 0.05) for telemark jumps than for telemark skiing. Barbell squats showed a knee angular amplitude significantly greater than that in telemark skiing (P < 0.05). The mean knee angular velocity of the F1 and E1 phases during telemark skiing was about 0.47 rad x s(-1); during barbell squats, it was about 1.22 rad x s(-1). The angular velocity during telemark jumps was 2.34 and 1.59 rad x s(-1) in the F1 and E1 phase, respectively. The normalized activation level of the EMG bursts during telemark skiing, telemark jumps and barbell squats was 70-80%. In conclusion, the muscle action and level of activation in the vastus lateralis during the F1 and E1 phases were similar during telemark skiing and dry-land exercises. However, the dry-land exercises showed a larger knee extension and flexion amplitude and angular velocity compared with telemark skiing. It appears that an adjustment of knee angular velocity during barbell squats and an adjustment of knee angle amplitude during both telemark jumps and barbell squats will improve specificity during training.
|
|
| 10. |
- Nilsson, Johnny, et al.
(author)
-
Pole length and ground reaction forces during maximal double poling in skiing.
- 2003
-
In: Sports biomechanics / International Society of Biomechanics in Sports. - : Informa UK Limited. - 1476-3141. ; 2:2, s. 227-36
-
Journal article (peer-reviewed)abstract
- The purpose of the investigation was to study the relationship between thrust phase duration, ground reaction force, velocity increase after pole thrust and pole angles versus pole length during double poling in roller skiing. Seven male regional elite cross-country skiers volunteered as subjects for the study. The subjects performed a maximal double pole thrust on roller skis with each of the three different pole lengths: 'short', self-selected (normal) and 'long'. The short and long poles were 7.5 cm shorter and 7.5 cm longer than the self-selected pole length. The subjects made seven maximal pole thrusts with each pole length, which were randomly selected during 21 trials. For each trial the subjects accelerated from a 1.2 m high downhill slope attaining a speed of 3.92 m.s-1 before making a maximal double pole thrust on a force plate placed at the bottom of the slope. The vertical (F2), anterior-posterior (Fy) and mediolateral (Fx) reaction forces of the left pole were measured by the force plate. The positions of the pole were recorded in 3-D by an opto-electronic system. Thrust phase duration, impulse, mean force, velocity increase after pole thrust and pole angles were calculated from the recorded data. Double poling with long poles produced a significantly larger propulsive anterior-posterior reaction force impulse and velocity increase than normal (p < .05) and short poles (p < .05). This was in spite of a larger mean anterior-posterior reaction force being produced with short poles. Thus, thrust phase duration was a primary factor in determining propulsive anterior-posterior impulse. For the practitioner, the results can be useful in the selection of pole length when the aim is to increase thrust phase duration, anterior-posterior force impulse and velocity.
|
|
