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Stooren O.,Telemark University College | Bratland-Sanda S.,Telemark University College | Haave M.,Telemark University College | Helgerud J.,Telemark University College | And 2 more authors.
Journal of Strength and Conditioning Research | Year: 2012

Improved VO2max and time trial performance with more high aerobic intensity interval training and reduced training volume: A case study on an elite national cyclist. J Strength Cond Res 26(10): 2705-2711, 2012-The present study investigated to what extent more high aerobic intensity interval training (HAIT) and reduced training volume would influence maximal oxygen uptake (VO2max) and time trial (TT) performance in an elite national cyclist in the preseason period. The cyclist was tested for VO2max, cycling economy (Cc), and TT performance on an ergometer cycle during 1 year. Training was continuously logged using heart rate monitor during the entire period. Totalmonthly training volume was reduced in the 2011 preseason compared with the 2010 preseason, and 2 HAIT blocks (14 sessions in 9 days and 15 sessions in 10 days) were performed as running. Between the HAIT blocks, 3 HAIT sessions per week were performed as cycling. From November 2010 to February 2011, the cyclist reduced total average monthly training volume by 18% and cycling training volume by 60%. The amount of training at 90-95% HRpeak increased by 41%. VO 2max increased by 10.3% on ergometer cycle. TT performance improved by 14.9%. Cc did not change. In conclusion, preseason reduced total training volume but increased amount of HAIT improved VO2max and TT performance without any changes in Cc. These improvements on cycling appeared despite that the HAIT blocks were performed as running. Reduced training time, and training transfer from running into improved cycling form, may be beneficial for cyclists living in cold climate areas. © 2012 National Strength and Conditioning Association. Source


Barrett-O'keefe Z.,University of Utah | Barrett-O'keefe Z.,Geriatric Research | Helgerud J.,Norwegian University of Science and Technology | Helgerud J.,Hokksund Medical Rehabilitation Center | And 4 more authors.
Journal of Applied Physiology | Year: 2012

Maximal strength training (MST) reduces pulmonary oxygen uptake (V̇O2) at a given submaximal exercise work rate (i.e., efficiency). However, whether the increase in efficiency originates in the trained skeletal muscle, and therefore the impact of this adaptation on muscle blood flow and arterial-venous oxygen difference (a-vO2diff), is unknown. Thus five trained subjects partook in an 8-wk MST intervention consisting of half-squats with an emphasis on the rate of force development during the concentric phase of the movement. Pre- and posttraining measurements of pulmonary V̇O2 (indirect calorimetry), single-leg blood flow (thermodilution), and single-leg a-vO2diff (blood gases) were performed, to allow the assessment of skeletal muscle V̇O2 during submaximal cycling [237 ± 23 W; ∼60% of their peak pulmonary V̇O2 (V̇O2peak)]. Pulmonary V̇O 2peak (∼4.05 l/min) and peak work rate (∼355 W), assessed during a graded exercise test, were unaffected by MST. As expected, following MST there was a significant reduction in pulmonary V̇O2 during steady-state submaximal cycling (∼237 W: 3.2±0.1 to 2.9±0.1 l/min). This was accompanied by a significant reduction in single-leg V̇O2 (1,101±105 to 935±93 ml/min) and single-leg blood flow (6,670 ± 700 to 5,649 ± 641 ml/min), but no change in single-leg a-vO2diff (16.7 ± 0.8 to 16.8 ±0.4 ml/dl). These data confirm an MSTinduced reduction in pulmonary V̇O2 during submaximal exercise and identify that this change in efficiency originates solely in skeletal muscle, reducing muscle blood flow, but not altering muscle a-vO2diff. © 2012 the American Physiological Society. Source


Fimland M.S.,Norwegian University of Science and Technology | Helgerud J.,Norwegian University of Science and Technology | Helgerud J.,Hokksund Medical Rehabilitation Center | Gruber M.,University of Potsdam | And 3 more authors.
European Journal of Applied Physiology | Year: 2010

Multiple sclerosis (MS) patients suffer from impaired muscle activation and lower limb strength. Strength training enhances muscle activation and muscle strength, but neural adaptations to strength training remain unexplored in MS patients. The hypothesis was that maximal strength training (MST) using high loads and few repetitions would improve central neural drive and thus strength capacity of MS patients. 14 MS patients staying at a national MS rehabilitation center were randomly assigned to a MST group or a control group (CG). Both groups received "today's treatment". In addition, the MST group trained 4 × 4 repetitions of unilateral dynamic leg press and plantar flexion 5 days a week for 3 weeks. Neural adaptations of the soleus muscle were assessed by surface electromyography (EMG) activity, and by superimposed H-reflexes and V-waves obtained during maximum voluntary isometric plantar flexor contractions (MVCs). H-reflexes and V-waves were normalized by the M-wave (H SUP/M SUP, V/M SUP, respectively). In the MST group, MVC increased by 20 ± 9% (P < 0.05). Soleus EMG activity and V/M SUP ratio increased by 40 and 55%, respectively, in the MST group compared to the CG (P ≤ 0.05). The H SUP/M SUP ratio remained unchanged. No change was apparent in the CG. MST group subjects were able to complete all training sessions. No adverse effects were reported. This randomized study provides evidence that MST is effective of augmenting the magnitude of efferent motor output of spinal motor neurons in MS patients, alleviating some neuromuscular symptoms linked to the disease. © 2010 Springer-Verlag. Source


Oyvind S.,Norwegian University of Science and Technology | Oyvind S.,Telemark University College | Helgerud J.,Norwegian University of Science and Technology | Helgerud J.,Hokksund Medical Rehabilitation Center | Hoff J.,Norwegian University of Science and Technology
Journal of Strength and Conditioning Research | Year: 2011

Støren, ø, Helgerud, J, and Hoff, J. Running stride peak forces inversely determines running economy in elite runners. J Strength Cond Res 25(1): 117-123, 2011-The present study investigated the relationship between running economy (RE) at 15 km/h-1, 3.000-m race time, maximal strength, and a number of physiological, anthropometrical, and mechanical variables. The variables measured included RE, maximal oxygen consumption, heart rate, step length and frequency, contact time, and the peak horizontal and vertical forces of each step. Maximal strength was measured as the 1 repetition maximum (1RM) half-squat using a leg press machine. Eleven male elite endurance athletes with a V̇O2max of 75.8 ± 6.2 mL/kg-1/ min-1 participated in this study. After the anthropometric data were collected, they were tested for RE, running characteristics, and force measures on a level treadmill at 15 km/h-1. The athletes wore contact soles, and the treadmill was placed on a force platform. Maximal oxygen consumption and 1RM were tested after the RE measurements. The sum of horizontal and vertical peak forces revealed a significant inverse correlation (p < 0.05) both with 3,000-m performance (R = 0.71) and RE (R = 0.66). Inverse correlations were also found (p < 0.05) between RE and body height (R = 0.61) and between RE and body fat percentage (R = 0.62). In conclusion, the sum of horizontal and vertical peak forces was found to be negatively correlated to running economy and 3,000-m running performance, indicating that avoiding vertical movements and high horizontal braking force is crucial for a positive development of RE. © 2011 National Strength and Conditioning Association. Source


Heggelund J.,Norwegian University of Science and Technology | Nilsberg G.E.,Norwegian University of Science and Technology | Hoff J.,Norwegian University of Science and Technology | Morken G.,Norwegian University of Science and Technology | And 3 more authors.
Nordic Journal of Psychiatry | Year: 2011

Background: Patients with schizophrenia have a high risk of cardiovascular disease (CVD). High aerobic intensity training (HIT) improve peak oxygen uptake (VO2peak), net mechanical efficiency of walking and risk factors for CVD but has not been investigated in patients with schizophrenia. Aims: To investigate effects from HIT on VO2peak, net mechanical efficiency of walking and risk factors for CVD in patients with schizophrenia. Methods: 25 inpatients (F2029, ICD-10) were allocated to either HIT or playing computer games (CG), 3 days per week for 8 weeks. HIT consisted of 4 × - 4-min intervals with 3-min break periods, at 8595% and 70% of peak heart rate, respectively. Results: 12 and seven patients completed HIT and CG, respectively. The baseline VO2peak in both groups combined (n = 19) was 36.8 ± 8.2 ml/kg/min and 3.12 ± 0.55 l/min. The HIT group improved VO2peak by 12% from 3.17 ± 0.59 to 3.56 ± 0.68 l/min (P < 0.001), more than the CG group (P = 0.014). Net mechanical efficiency of walking improved by 12% in the HIT group from 19.8 ± 3.0% to 22.2 ± 4.5% (P = 0.005), more than the CG group (P = 0.031). The psychiatric symptoms, expressed as the Positive and Negative Syndrome Scale (PANSS) and the Calgary Depression Scale for Schizophrenia (CDSS), did not improve in either group. Conclusions: VO2peak and net mechanical efficiency of walking improved significantly by 8 weeks of HIT. HIT should be included in rehabilitation in order to improve physical capacity and contribute risk reduction of CVD. © 2011 Informa Healthcare. Source

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