Tieteelliset julkaisut

Harri Selänne on julkaissut mittavan uransa aikana kymmeniä tieteellisiä artikkeleita ja julkaisuja. Sivustolle on kerätty matkan varrelta niistä merkittävimpiä.

Valitse sivun oikean reunan artikkeliarkistosta luettavaksesi tieteelliset ja kansainväliset julkaisut tai artikkelit, jotka on julkaistu harrastaja-, aikakausi- ja sanomalehdissä.

Lisätietoja artikkeleihin ja julkaisuihin liittyen saat ottamalla yhteyttä Harriin mieluiten Sähköpostiosoite on suojattu roskapostiohjelmia vastaan, Javascript-tuen tulee olla päällä nähdäksesi osoitteen .

Transnational athletes’ lifestories: Reflexivity in research.

  • 07.10.2013 14:13

Harri Selänne

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Cultural competence and ethics of difference in sport psychology research and practice.

  • 07.10.2013 14:09

Ryba, T. V., Stambulova, N. B., Schinke, Si, Selänne, N. Ronkainen

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Body composition in 18 to 88-year-old adults - comparison of multifrequency bioimpedance and dual-energy X-ray absorptiometry.

  • 07.10.2013 14:06

Elina Sillanpää, Sulin Cheng, Keijo Häkkinen, Taija Finni, Simon Walker, Arto Pesola, Juha Ahtiainen, Lauri Stenroth, Harri Selänne, Sarianna Sipilä

Objective: This study compared bioimpedance analysis (BIA) in the assessment of body composition with dual-energy X-ray absorptiometry (DXA) in 18-88 year-old adults. Design and Methods: Body composition of 882 adults was estimated by eight-polar BIA and DXA. In addition, estimates of lean mass, fat mass and percentage of fat were investigated across a range of age and leisure time physical activity (LTPA) groups. Results: Compared to DXA, larger lean masses (mean difference 2.9 and 1.6kg) and smaller fat masses (3.1 and 2.6kg) were estimated by BIA in both women and men, respectively. Differences between the methods' mean values were evident in all age and LTPA groups, except in the oldest men (over 70 years). Age, waist circumference, grip strength and LTPA explained 21% or less of the variance observed in the differences between methods. Conclusions: Compared to DXA, BIA provided systematically different body composition estimates throughout the adult age span with considerable amount of intraindividual variation. The differences between estimates may be related to the BIAs' algorithm or body geometry or composition of the population used in this study. Knowledge about the methodological limitations and device comparability is essential for researchers, clinicians and persons working in rehabilitation and sport centers.

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Is gender useful in understanding a transnational athletic career? In Harmony and excellence in sport and life.

  • 07.10.2013 14:04

Ryba, T. V., Ronkainen, N., Selänne, H., Stambulova, N. B., & Bundgaard, J

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Effects of high-impact training on bone and articular cartilage: 12 months randomized controlled quantitative magnetic resonance imaging study.

  • 07.10.2013 13:53

Juhani Multanen, Miika T Nieminen, Arja Häkkinen, Urho M Kujala, Timo Jämsä, Hannu Kautiainen, Eveliina Lammentausta, Riikka Ahola, Harri Selänne, Risto Ojala, Ilkka Kiviranta, Ari Heinonen

Osteoarthritis and osteoporosis often coexist in postmenopausal women. The simultaneous effect of bone-favorable high-impact training on these diseases is not well understood and is a topic of controversy. We evaluated the effects of high-impact exercise on bone mineral content (BMC) and the estimated biochemical composition of knee cartilage in postmenopausal women with mild knee osteoarthritis. Eighty women aged 50-66 years with mild knee osteoarthritis were randomly assigned to undergo supervised progressive exercise 3 times a week for 12 months (n = 40) or to a non-intervention control group (n = 40). BMC of the femoral neck, trochanter and lumbar spine was measured by dual-energy X-ray absorptiometry (DXA). The biochemical composition of cartilage was estimated using delayed gadolinium-enhanced MRI of cartilage (dGEMRIC), sensitive to cartilage glycosaminoglycan content, and T2 mapping that is sensitive to the properties of the collagen network. In addition, clinically important symptoms and as physical performance related risk factors of falling; dynamic balance, maximal isometric knee extension and flexion forces, leg power and cardiorespiratory fitness were evaluated. Thirty-six trainees and 40 controls completed the study. The mean gain in femoral neck BMC in the exercise group was 0.6% (95% CI: -0.2 to 1.4) and the mean loss in the control group was -1.2% (95% CI: -2.1 to -0.4). The baseline, body mass and body mass change adjusted BMC change between the groups was significant (P = 0.005), while no changes occurred in the biochemical composition of the cartilage, as investigated by MRI. Balance, muscle force and cardiorespiratory fitness improved significantly more (3-11%) in the exercise group than in the control group. Progressively implemented high-impact training, which increased bone mass, did not affect the biochemical composition of cartilage and may be feasible in the prevention of osteoporosis and physical performance related risk factors of falling in postmenopausal women.

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Motor unit firing behaviour of soleus muscle in isometric and dynamic contractions.

  • 07.10.2013 13:47

Jouni Kallio, Karen Søgaard, Janne Avela, Paavo V Komi, Harri Selänne, Vesa Linnamo

Understanding the detailed control of human locomotion and balance can be improved, when individual motor units can be isolated and their firing rates followed in natural movement of large, fuctionally important muscles. For this reason the present study investigated the motor unit discharge rate (MUDR) in isometric and dynamic contractions of the soleus muscle. Eleven males performed isometric (10-100% MVC) and dynamic (10-40% MVC) plantar flexions. Intramuscular EMG was measured from Soleus with bipolar wire-electrodes and decomposed with custom built "Daisy" software. The Soleus MUDR was significantly higher in concentric compared to isometric or eccentric contractions at all submaximal force levels (P<0.05). In isometric contractions MUDR increased up to 100% MVC. Motor unit discharge properties of a large plantarflexor can be measured in dynamic and maximal contractions. For a given torque output, MUDR is dependent upon contraction type, as set by the major mechanical differences between concentric and eccentric actions.

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Effects of a progressive aquatic resistance exercise program on the biochemical composition and morphology of cartilage in women with mild knee osteoarthritis: protocol for a randomised controlled trial.

  • 07.10.2013 13:43

Benjamin Waller, Matti Munukka, Juhani Multanen, Timo Rantalainen, Tapani Pöyhönen, Miika T Nieminen, Ilkka Kiviranta, Hannu Kautiainen, Harri Selänne, Joost Dekker, Sarianna Sipilä, Urho M Kujala, Arja Häkkinen, Ari Heinonen

Symptoms associated with osteoarthritis of the knee result in decreased function, loss of working capacity and extensive social and medical costs. There is a need to investigate and develop effective interventions to minimise the impact of and even prevent the progression of osteoarthritis. Aquatic exercise has been shown to be effective at reducing the impact of osteoarthritis. The purpose of this article is to describe the rationale, design and intervention of a study investigating the effect of an aquatic resistance exercise intervention on cartilage in postmenopausal women with mild knee osteoarthritis. A minimum of 80 volunteers who meet the inclusion criteria will be recruited from the local population through newspaper advertisements. Following initial assessment volunteers will be randomised into two groups. The intervention group will participate in a progressive aquatic resistance exercise program of 1-hour duration 3 times a week for four months. The control group will be asked to maintain normal care during this period. Primary outcome measure for this study is the biochemical composition of knee cartilage measured using quantitative magnetic resonance imaging; T2 relaxation time and delayed gadolinium-enhanced magnetic resonance imaging techniques. In addition, knee cartilage morphology as regional cartilage thickness will be studied. Secondary outcomes include measures of body composition and bone traits using dual energy x-ray absorptiometry and peripheral quantitative computed tomography, pain, function using questionnaires and physical performance tests and quality of life. Measurements will be performed at baseline, after the 4-month intervention period and at one year follow up. This randomised controlled trial will investigate the effect a progressive aquatic resistance exercise program has on the biochemical composition of cartilage in post-menopausal women with mild knee osteoarthritis. This is the first study to investigate what impact aquatic exercise has on human articular cartilage. In addition it will investigate the effect aquatic exercise has on physical function, pain, bone and body composition and quality of life. The results of this study will help optimise the prescription of aquatic exercise to persons with mild knee osteoarthritis.
ISRCTN65346593.

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Common features in overtrained athletes and individuals with professional burnout: Implications for sports medical practice

  • 07.10.2013 13:42

Harri Selänne, Tatiana V Ryba, Juhani Leppäluoto

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Resistance training induced increase in muscle fiber size in young and older men.

  • 07.10.2013 13:37

A A Mero, J J Hulmi, H Salmijärvi, M Katajavuori, M Haverinen, J Holviala, T Ridanpää, K Häkkinen, V Kovanen, J P Ahtiainen, H Selänne

Muscle strength and mass decline in sedentary individuals with aging. The present study investigated the effects of both age and 21 weeks of progressive hypertrophic resistance training (RT) on skeletal muscle size and strength, and on myostatin and myogenin mRNA expression in 21 previously untrained young men (26.0 ± 4.3 years) and 18 older men (61.2 ± 4.1 years) and age-matched controls. Vastus lateralis muscle biopsies were taken before and after RT. Type I and type II muscle fiber cross-sectional areas increased more in young men than in older men after RT (P < 0.05). Concentric leg extension increased (P < 0.05) more after 10.5 weeks in young men compared to older men, but after 21 weeks no statistical differences existed. The daily energy and protein intake were greater (P < 0.001) in young subjects. Both myostatin and myogenin mRNA expression increased in older when compared with young men after RT (P < 0.05). In conclusion, after RT, muscle fiber size increased less in older compared to young men. This was associated with lower protein and energy intake and increases in myostatin gene expression in older when compared to young men.

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Age-related decreases in motor unit discharge rate and force control during isometric plantar flexion.

  • 07.10.2013 13:32

J Kallio, K Søgaard, J Avela, P Komi, H Selänne, V Linnamo

Aging is related to multiple changes in muscle physiology and function. Previous findings concerning the effects of aging on motor unit discharge rate (DR) and fluctuations in DR and force are somewhat contradictory. Eight YOUNG and nine OLD physically active males performed isometric ramp (RECR) and isotonic (ISO) plantar flexions at 10 and 20% of surface EMG at MVC. Motor unit (MU) action potentials were recorded with intramuscular fine-wire electrodes and decomposed with custom build software "Daisy". DR was lower in OLD in RECR-10% (17.9%, p<0.001), RECR-20% (15.8%, p<0.05), ISO-10% (17.7%, p<0.01) and ISO-20% (14%, n.s.). In YOUNG force fluctuations were smaller at ISO-10% (72.1%, p<0.001) and ISO-20% (55.2%, p<0.05) which were accompanied with a slight increase in DR variation (n.s.). The observed lower DR in OLD is in line with earlier findings in small distal muscles. Also the larger force fluctuation in OLD was in line with previous studies with smaller hand muscles. These findings suggest that the age-related changes in MU control do exist also in large leg extensors that play an important role in human locomotion and balance control.

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Recovery after Heavy Resistance Exercise and Skeletal Muscle Androgen Receptor and Insulin-Like Growth Factor-I Isoform Expression in Strength Trained Men

  • 07.10.2013 13:28

Juha P Ahtiainen, Maarit Lehti, Juha J Hulmi, William J Kraemer, Markku Alen, Kai Nyman, Harri Selänne, Arto Pakarinen, Jyrki Komulainen, Vuokko Kovanen, Antti A Mero, Keijo Häkkinen

Ahtiainen, JP, Lehti, M, Hulmi, JJ, Kraemer, WJ, Alen, M, Nyman, K, Selänne, H, Pakarinen, A, Komulainen, A, Kovanen, V, Mero, AA, and Häkkinen, K. Recovery after heavy resistance exercise and skeletal muscle androgen receptor and insulin-like growth factor-I isoform expression in strength trained men. J Strength Cond Res 25(3): 767-777, 2011-The effects of heavy resistance exercise on skeletal muscle androgen receptor (AR) protein concentration and mRNAs of AR, insulin-like growth factor-I (IGF)-IEa, and mechano growth factor (MGF) expression were examined from biopsies of vastus lateralis (VL) muscle before and 48 hours after heavy resistance exercise (5 × 10 repetition maximum [RM] leg press and 4 × 10RM squats) in 8 adult strength trained men. The present exercise induced an acute decrease in maximal isometric force and increased serum total testosterone (T) and free testosterone (FT) concentrations. During 2 recovery days, maximal isometric force and subjective perception of physical fitness remained significantly lowered, whereas serum creatine kinase activity, subjective muscle soreness, and muscle swelling (i.e., thickness of VL by ultrasound) were significantly increased compared to pre-exercise values. Subjective perception of physical fitness was followed up to 7 days, and by 6 days postexercise, it was elevated above the pre-exercise level. Basal T and FT concentrations remained unaltered after the exercise. No statistically significant changes were observed in AR protein or mRNA expression, but IGF-IEa (p < 0.05) and MGF (p < 0.05) mRNA expression were increased compared to pre-exercise levels. These findings indicate that IGF-IEa and MGF responses may be related to acute regenerative processes in muscle because of exercise and may contribute to muscular adaptation to resistance exercise. Subjective perception of physical fitness suggests that recovery over a pre-exercise level of the present type of heavy resistance exercise can take approximately 6 days.

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Heavy resistance exercise training and skeletal muscle androgen receptor expression in younger and older men.

  • 07.10.2013 13:25

Juha P Ahtiainen, Juha J Hulmi, William J Kraemer, Maarit Lehti, Kai Nyman, Harri Selänne, Markku Alen, Arto Pakarinen, Jyrki Komulainen, Vuokko Kovanen, Antti A Mero, Keijo Häkkinen

Effects of heavy resistance exercise on serum testosterone and skeletal muscle androgen receptor (AR) concentrations were examined before and after a 21-week resistance training period. Seven healthy untrained young adult men (YT) and ten controls (YC) as well as ten older men (OT) and eight controls (OC) volunteered as subjects. Heavy resistance exercise bouts (5 × 10 RM leg presses) were performed before and after the training period. Muscle biopsies were obtained before and 1h and 48 h after the resistance exercise bouts from m.vastus lateralis (VL) to determine cross-sectional area of muscle fibers (fCSA) and AR mRNA expression and protein concentrations. No changes were observed in YC and OC while resistance training led to significant increases in maximal strength of leg extensors (1 RM), fCSA and lean body mass in YT and OT. Acute increases occurred in serum testosterone concentrations due to resistance exercises but basal testosterone remained unaltered. Mean AR mRNA expression and protein concentration remained unchanged after heavy resistance exercise bouts compared to pre-values. The individual pre- to post-training changes in resting (pre-exercise) AR protein concentration correlated with the changes in fCSA and lean body mass in the combined group of YT and OT. Similarly, it correlated with the changes in 1 RM in YT. Although mean AR expression did not changed due to the resistance exercise training, the present findings suggest that the individual changes of AR protein concentration in skeletal muscle following resistance training may have an impact on training-induced muscular adaptations in both younger and older men.

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Effects of ageing on motor unit activation patterns and reflex sensitivity in dynamic movements.

  • 07.10.2013 13:17

J Kallio, J Avela, T Moritani, M Kanervo, H Selänne, P Komi, V Linnamo

Both contraction type and ageing may cause changes in H-reflex excitability. H reflex is partly affected by presynaptic inhibition that may also be an important factor in the control of MU activation. The purpose of the study was to examine age related changes in H-reflex excitability and motor unit activation patterns in dynamic and in isometric contractions. Ten younger (YOUNG) and 13 elderly (OLD) males performed isometric (ISO), concentric (CON) and eccentric (ECC) plantarflexions with submaximal activation levels (20% and 40% of maximal soleus surface EMG). Intramuscular EMG data was analyzed utilizing an intramuscular spike amplitude frequency histogram method. Average H/M ratio was always lowest in ECC (n.s.). Mean spike amplitude increased with activation level (P<.05), whereas no significant differences were found between contraction types. Both H-reflex excitability, which may be due to an increase in presynaptic inhibition, and mean spike frequency were higher in YOUNG compared to OLD. In OLD the mean spike frequency was significantly smaller in CON compared to ISO. Lack of difference in mean spike amplitude and frequency across contraction types in YOUNG would imply a similar activation strategy, whereas the lower frequency in dynamic contractions in OLD could be related to synergist muscle behavior.

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Seventy-year-old habitual volleyball players have larger tibial cross-sectional area and may be differentiated from their age-matched peers by the osteogenic index in dynamic performance.

  • 07.10.2013 13:15

T Rantalainen, V Linnamo, P V Komi, H Selänne, A Heinonen

The osteogenicity of a given exercise may be estimated by calculating an osteogenic index (OI) consisting of magnitude and rate of strain. Volleyball involves repetitive jumping and requires high power output and thus may be expected to be beneficial to bone and performance. The purpose of the present study was to examine if habitual volleyball playing is reflected in OI. Ten elderly habitual volleyball players [age 69.9 (SD 4.4) years] and ten matched controls volunteered [age 69.7 (4.2) years] as subjects. Distal tibia (d), tibial mid-shaft (50) and femoral neck (FN) bone characteristics were measured using pQCT and DXA. To estimate skeletal rigidity, cross-sectional area (ToA(50)), and compressive (BSI(d)) and bending strength indices (SSImax(50)) were calculated. Maximal performance was assessed with eccentric ankle plantar flexion, isometric leg press and countermovement jump (CMJ). A fast Fourier transform (FFT) was calculated from the acceleration of the center of mass during the CMJ. Maximal acceleration (MAG) and mean magnitude frequency (MMF) were selected to represent the constituents of OI. OI was calculated as the sum of the products of magnitudes and corresponding frequencies. Volleyball players had 7% larger ToA(50) and 37% higher power in CMJ, 15% higher MAG and 36% higher OI (P or= 0.646). In conclusion, habitual volleyball players may be differentiated from their matched peers by their dynamic jumping performance, and the differences are reflected in the magnitude but not rate of loading.

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Strength, [corrected] endurance or combined training elicit diverse skeletal muscle myosin heavy chain isoform proportion but unaltered androgen receptor concentration in older men.

  • 07.10.2013 13:07

J P Ahtiainen, J J Hulmi, W J Kraemer, M Lehti, A Pakarinen, A A Mero, L Karavirta, E Sillanpää, H Selänne, M Alen, J Komulainen, V Kovanen, K Nyman, K Häkkinen

We investigated whether the myosin heavy chain (MyHC) proportion and androgen receptor (AR) concentration in skeletal muscle differ following 21 weeks of strength, endurance and combined training in untrained older men. Strength (S) and endurance (E) groups trained twice per week and combined (S+E) group trained four times per week (two strength and two endurance). Muscle biopsies were obtained before and after the training period from m. vastus lateralis (VL) and AR mRNA and protein concentration and MyHC proportion were determined. 1RM increased during the training period in S, S+E and E but the changes were greater in S and S+E than in E. Statistically significant increases were observed only in S and S+E in maximal isometric force as well as in VL thickness. VO (2max) increased significantly only in E. MyHCIIa proportion increased in S, while MyHCIIa proportion decreased and MyHCI increased (p<0.05) in E. No statistically significant changes were observed in serum testosterone and in AR mRNA or protein concentrations. The present results indicate that 21 weeks of strength, endurance or combined training changed MyHC proportion according to the training method but did not have an effect on AR mRNA or protein expression in skeletal muscle at rest.

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Bone rigidity to neuromuscular performance ratio in young and elderly men.

  • 07.10.2013 13:02

T Rantalainen, H Sievänen, V Linnamo, M Hoffrén, M Ishikawa, H Kyröläinen, J Avela, H Selänne, P V Komi, A Heinonen

Given the adaptation of bone to prevalent loading, bone loss should follow, but lag behind, the decline in physical performance during aging. Furthermore, bone responsiveness to load-induced strains is believed to decrease with aging. However, the relationship between bone and lean body ( approximately muscle) mass appears to remain rather constant throughout adulthood. The purpose of this study was to examine the association between age and bone to neuromuscular performance ratio. Young (N=20, age 24 SD+/-2 years, body mass 77+/-11 kg, height 178+/-6 cm) and elderly (N=25, 72+/-4 years, 75+/-9 kg, 172+/-5 cm) men served as subjects. Bone structural traits were measured at the right distal tibia and tibial mid-shaft with peripheral quantitative computed tomography (pQCT). Maximal section modulus (Z(max50)), total area (ToA(d)), cortical area (CoA(50)), total density (ToD(d)) and cortical density (CoD(50)) were determined from the pQCT images. Neuromuscular performance was measured by recording vertical ground reaction force (GRF) in maximal bilateral hopping. Load-induced strains were estimated by calculating appropriate indices for compressive and tensile loading that took into account both the bone structure and apparent biomechanics of the given bone site. Young subjects had significantly higher maximal GRF compared to older men (4260+/-800 N vs. 3080+/-600 N, P<0.001). They also had smaller ToA(d) (1100+/-170 mm(2) vs. 1200+/-100 mm(2), P=0.028) while their ToD(d) was higher (370+/-46 g/cm(3) vs. 330+/-22 g/cm(3), P=0.002). The Z(max50) did not differ significantly between young (1660+/-320 mm(3)) and elderly men (1750+/-320 mm(3)) (P=0.224). Compressive (0.484+/-0.102 vs. 0.399+/-0.078, P=0.016) and tensile (0.107+/-0.016 vs. 0.071+/-0.018, P<0.001) strain indices were significantly higher in the younger group. In conclusion, the difference in bone to loading ratio at the tibial mid-shaft is bigger than expected from the delay in bone adaptation alone. Potential candidates to explain this phenomenon include a decrease in mechanosensitivity with aging, inability of maximal physical performance to adequately represent the bone loading environment, or the need to maintain constant safety factors to functional strains.

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Acute and long-term effects of resistance exercise with or without protein ingestion on muscle hypertrophy and gene expression.

  • 07.10.2013 12:59

Juha J Hulmi, Vuokko Kovanen, Harri Selänne, William J Kraemer, Keijo Häkkinen, Antti A Mero

The effects of timed ingestion of high-quality protein before and after resistance exercise are not well known. In this study, young men were randomized to protein (n = 11), placebo (n = 10) and control (n = 10) groups. Muscle cross-sectional area by MRI and muscle forces were analyzed before and after 21 weeks of either heavy resistance training (RT) or control period. Muscle biopsies were taken before, and 1 and 48 h after 5 x 10 repetition leg press exercise (RE) as well as 21 weeks after RT. Protein (15 g of whey both before and after exercise) or non-energetic placebo were provided to subjects in the context of both single RE bout (acute responses) as well as each RE workout twice a week throughout the 21-week-RT. Protein intake increased (P < or = 0.05) RT-induced muscle cross-sectional area enlargement and cell-cycle kinase cdk2 mRNA expression in the vastus lateralis muscle suggesting higher proliferating cell activation response with protein supplementation. Moreover, protein intake seemed to prevent 1 h post-RE decrease in myostatin and myogenin mRNA expression but did not affect activin receptor IIb, p21, FLRG, MAFbx or MyoD expression. In conclusion, protein intake close to resistance exercise workout may alter mRNA expression in a manner advantageous for muscle hypertrophy.

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Resistance exercise with whey protein ingestion affects mTOR signaling pathway and myostatin in men.

  • 07.10.2013 12:22

Juha J Hulmi, Jörgen Tannerstedt, Harri Selänne, Heikki Kainulainen, Vuokko Kovanen, Antti A Mero

Signaling pathways sense local and systemic signals and regulate muscle hypertrophy. The effects of whey protein ingestion on acute and long-term signaling responses of resistance exercise are not well known. Previously untrained young men were randomized into protein (n = 9), placebo (n = 9), and control (n = 11) groups. Vastus lateralis (VL) muscle biopsies were taken before and 1 h and 48 h after a leg press of 5 x 10 repetitions [resistance exercise (RE)] and after 21 wk (2 times per week) of resistance training (RT). Protein (15 g of whey) or nonenergetic placebo was ingested before and after a single RE bout and each RE workout throughout the RT. The protein group increased its body mass and VL muscle thickness (measured by ultrasonography) already at week 10.5 (P < 0.05). At week 21, the protein and placebo groups had similarly increased their myofiber size. No changes were observed in the nonexercised controls. However, the phosphorylation of p70(S6K) and ribosomal protein S6 (rpS6) were increased at 1 h post-RE measured by Western blotting, the former being the greatest with protein ingestion. Mammalian target of rapamycin (mTOR) phosphorylation was increased after the RE bout and RT only in the protein group, whereas the protein ingestion prevented the post-RE decrease in phosphorylated eukaryotic initiation factor 4E binding protein 1 (p-4E-BP1). Akt phosphorylation decreased after RT, whereas no change was observed in phosphorylated eukaryotic elongation factor 2. A post-RE decrease in muscle myostatin protein occurred only in the placebo group. The results indicate that resistance exercise rapidly increases mTOR signaling and may decrease myostatin protein expression in muscle and that whey protein increases and prolongs the mTOR signaling response.

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Androgen receptors and testosterone in men--effects of protein ingestion, resistance exercise and fiber type.

  • 07.10.2013 12:18

Juha J Hulmi, Juha P Ahtiainen, Harri Selänne, Jeff S Volek, Keijo Häkkinen, Vuokko Kovanen, Antti A Mero

The purpose of this study was to examine the impact of protein ingestion on circulating testosterone and muscle androgen receptor (AR) as well as on insulin-like growth factor-I (MGF and IGF-IEa) responses to a resistance exercise (RE) bout in (57-72 year) men. Protein (15 g whey) (n=9) or placebo (n=9) was consumed before and after a RE bout (5 sets of 10 repetition maximums), and vastus lateralis muscle biopsies were taken pre, 1 and 48 h post-RE. The protein ingestion blunted the RE-induced increase in serum free and total testosterone while the RE bout significantly increased muscle AR mRNA levels in older men (P<0.05). However, protein ingestion did not significantly affect AR mRNA or protein expression, or MGF and IGF-IEa mRNA expression at 1 and 48 h post-RE. Immunohistochemical staining of muscle cross-sections was done with antibodies specific to AR and MyHC I and II and showed that there seems to be within or near the type-I muscle fibers a greater staining of ARs than within or near the type-II fibres. In conclusion, the protein ingestion hinders RE-induced increase in serum testosterone in older men but may not significantly affect muscle AR, MGF or IGF-IEa gene expression. Furthermore, the present study shows that even older men are able to increase muscle AR mRNA expression in response to a RE bout.

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The effects of whey protein on myostatin and cell cycle-related gene expression responses to a single heavy resistance exercise bout in trained older men.

  • 07.10.2013 12:14

Juha J Hulmi, Vuokko Kovanen, Inna Lisko, Harri Selänne, Antti A Mero

Myostatin decreases muscle mass and this is accomplished, in part, by inhibiting muscle satellite cell proliferation and differentiation by regulating the expression of cell cycle-related proteins (e.g. p21 and cdk2) and myogenic regulatory factors (e.g. myogenin and MyoD). The purpose of this investigation was to determine whether protein ingestion before and after a resistance exercise (RE) bout affects myostatin and cell cycle-related gene expression. Strength-trained middle-aged to older men were divided into a protein group (61.4 +/- 4.3 years, n = 9) or a placebo group (62.1 +/- 4.2 years, n = 9). Muscle biopsies from the vastus lateralis muscle were taken at rest and 1 and 48 h after a 5 x 10 repetition leg press RE bout. Protein (15 g whey) or non-caloric placebo was taken immediately before and after the RE bout. mRNA expression levels of myostatin and related genes (AcvrIIb, FLRG, p21, p27, cdk2, myogenin and MyoD) were determined by Taqman probe-based real-time RT-PCR and normalized to GAPDH mRNA. Myostatin mRNA decreased after a RE bout, but only in the placebo group (P < or = 0.05). Conversely, myostatin-binding protein FLRG and cell-cycle kinase cdk2 mRNA increased only in the protein group (P < or = 0.05). p21 mRNA was increased at 1 h post-RE in placebo (P < or = 0.05) and tended to be increased in the protein group (P = 0.08). Myostatin, its binding protein and cell cycle-related gene expressions are affected by single RE bout and these responses are further modified by whey protein intake. Therefore, controlling nutrition intake is important when studying gene expression responses to exercise.

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A single bout of exercise with high mechanical loading induces the expression of Cyr61/CCN1 and CTGF/CCN2 in human skeletal muscle.

  • 07.10.2013 12:04

Riikka Kivelä, Heikki Kyröläinen, Harri Selänne, Paavo V Komi, Heikki Kainulainen, Veikko Vihko

High mechanical loading was hypothesized to induce the expression of angiogenic and/or lymphangiogenic extracellular matrix (ECM) proteins in skeletal muscle. Eight men performed a strenuous exercise protocol, which consisted of 100 unilateral maximal drop jumps followed by submaximal jumping until exhaustion. Muscle biopsies were taken 30 min and 48 h postexercise from the vastus lateralis muscle and analyzed for the following parameters: mRNA and protein expression of ECM-associated CCN proteins [cysteine-rich angiogenic protein 61 (Cyr61)/CCN1, connective tissue growth factor (CTGF)/CCN2], and mRNA expression of vascular endothelial growth factors (VEGFs) and hypoxia-inducible factor-1alpha. The mRNA expression of Cyr61 and CTGF increased 30 min after the exercise (14- and 2.5-fold, respectively; P < 0.001). Cyr61 remained elevated 48 h postexercise (threefold; P < 0.05). The mRNA levels of VEGF-A, VEGF-B, VEGF-C, VEGF-D, or hypoxia-inducible factor-1alpha did not change significantly at either 30 min or 48 h postexercise; however, the variation between subjects increased markedly in VEGF-A and VEGF-B mRNA. Cyr61 protein levels were higher at both 30 min and 48 h after the exercise compared with the control (P < 0.05). Cyr61 and CTGF proteins were localized to muscle fibers and the surrounding ECM by immunohistochemistry. Fast fibers stained more intensively than slow fibers. In conclusion, mechanical loading induces rapid expression of CCN proteins in human skeletal muscle. This may be one of the early mechanisms involved in skeletal muscle remodeling after exercise, since Cyr61 and CTGF regulate the expression of genes involved in angiogenesis and ECM remodeling.

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Postexercise myostatin and activin IIb mRNA levels: effects of strength training.

  • 07.10.2013 11:52

Juha J Hulmi, Juha P Ahtiainen, Tuomas Kaasalainen, Eija Pöllänen, Keijo Häkkinen, Markku Alen, Harri Selänne, Vuokko Kovanen, Antti A Mero

Muscle hypertrophy is likely to result from the cumulative effects of repeated bouts of resistance exercise (RE) on postexercise molecular responses. Therefore, we determined muscle growth- and regeneration-related mRNA expression in response to a single RE bout both before and after a strength-training (ST) period. By means of this novel longitudinal setting, we examined whether postexercise gene expression at the transcriptional level is different in the trained and untrained state. Eleven untrained healthy older men and 11 controls (age 62.3 +/- 6.3 yr) volunteered as subjects. Muscle biopsies from the vastus lateralis muscle were taken at rest and 1 and 48 h after five sets of 10-repetition leg press RE both before and after 21 wk of supervised ST. Myostatin and myogenin mRNA expression, determined by real-time RT-PCR, increased (P < 0.05) after ST. Conversely, the single RE bout decreased myostatin mRNA after ST, with the decrease showing a negative correlation (r = -0.65, P < 0.05) with the long-term increase in myostatin during ST. Furthermore, RE before ST increased myogenin mRNA (P < 0.05) and tended to increase after ST (P = 0.08). Myostatin receptor activin IIb mRNA levels were decreased at 1 h after RE in the pre-ST condition (P = 0.05) and also tended to decrease in the post-ST condition (P = 0.07). RE-induced downregulation in myostatin mRNA correlated with the ST-induced increase in total body muscle mass (r = -0.82, P = 0.002). A single bout of RE in older men can downregulate the expression of myostatin receptor activin IIb mRNA. ST influences the response of myostatin to RE, as short-term RE-induced downregulation of myostatin was observed only after ST. The results also indicate that RE-induced alterations in myostatin mRNA expression may have a role in ST-induced muscle hypertrophy.

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Postexercise Myostatin and Activin IIb mRNA Levels: Effects of Strength Training

  • 07.10.2013 11:45

JUHA J. HULMI, JUHA P. AHTIAINEN, TUOMAS KAASALAINEN, EIJA PöLLANEN, KEIJO HAKKINEN, MARKKU ALEN, HARRI SELANNE, VUOKKO KOVANEN, ANTTI A. MERO

Purpose: Muscle hypertrophy is likely to result from the cumulative effects of repeated bouts of resistance exercise (RE) on postexercise molecular responses. Therefore, we determined muscle growth- and regeneration-related mRNA expression in response to a single RE bout both before and after a strength-training (ST) period. By means of this novel longitudinal setting, we examined whether postexercise gene expression at the transcriptional level is different in the trained and untrained state.

Methods: Eleven untrained healthy older men and 11 controls (age 62.3 ± 6.3 yr) volunteered as subjects. Muscle biopsies from the vastus lateralis muscle were taken at rest and 1 and 48 h after five sets of 10-repetition leg press RE both before and after 21 wk of supervised ST.

Results: Myostatin and myogenin mRNA expression, determined by real-time RT-PCR, increased (P < 0.05) after ST. Conversely, the single RE bout decreased myostatin mRNA after ST, with the decrease showing a negative correlation (r = -0.65, P < 0.05) with the long-term increase in myostatin during ST. Furthermore, RE before ST increased myogenin mRNA (P < 0.05) and tended to increase after ST (P = 0.08). Myostatin receptor activin IIb mRNA levels were decreased at 1 h after RE in the pre-ST condition (P = 0.05) and also tended to decrease in the post-ST condition (P = 0.07). RE-induced downregulation in myostatin mRNA correlated with the ST-induced increase in total body muscle mass (r = -0.82, P = 0.002).

Conclusions: A single bout of RE in older men can downregulate the expression of myostatin receptor activin IIb mRNA. ST influences the response of myostatin to RE, as short-term RE-induced downregulation of myostatin was observed only after ST. The results also indicate that RE-induced alterations in myostatin mRNA expression may have a role in ST-induced muscle hypertrophy.

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Effects of exhaustive stretch-shortening cycle exercise on muscle blood flow during exercise.

  • 07.10.2013 11:37

M S Laaksonen, R Kivelä, H Kyröläinen, S Sipilä, H Selänne, R Lautamäki, P Nuutila, J Knuuti, K K Kalliokoski, P V Komi

The influence of exhaustive stretch-shortening cycle exercise (SSC) on skeletal muscle blood flow (BF) during exercise is currently unknown. Quadriceps femoris (QF) BF was measured in eight healthy men using positron emission tomography before and 3 days after exhaustive SSC exercise. The SSC protocol consisted of maximal and submaximal drop jumps with one leg. Needle biopsies of the vastus lateralis muscles were taken immediately and 2 days after SSC for muscle endothelial nitric oxide synthase (eNOS) and interleukin-1-beta (IL-1beta) mRNA level determinations. All subjects reported subjective muscle soreness after SSC (P < 0.001), which was well in line with a decrease in maximal isometric contraction force (MVC) and increase in serum creatine kinase activity (CK) (P = 0.018). After SSC muscle BF was 25% higher in entire QF (P = 0.043) and in its deep and superficial muscle regions, whereas oxygen uptake remained unchanged (P = 0.893). Muscle biopsies revealed increased IL-1beta (30 min: 152 +/- 75%, P = 0.012 and 2 days: 108 +/- 203%, P = 0.036) but decreased or unchanged eNOS (30 min; -21 +/- 57%, P = 0.050 and 2 days: +101 +/- 204%, P = 0.779) mRNA levels after SSC. It was concluded that fatiguing SSC exercise induces increased muscle BF during exercise, which is likely to be associated with pro-inflammatory processes in the exercised muscle.

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Protein ingestion prior to strength exercise affects blood hormones and metabolism.

  • 07.10.2013 11:31

Juha J Hulmi, Jeff S Volek, Harri Selänne, Antti A Mero

The effects of protein consumption before strength training session on blood hormones, energy metabolites, RER, and excess postexercise oxygen consumption (EPOC) were examined. Ten resistance-trained young men consumed either a 25 g of whey and caseinate proteins (PROT) or a noncaloric placebo (P) in a liquid form 30 min before a heavy strength training session (STS) in a crossover design separated by at least 7 d. STS lasted 50 min and included 5 x 1 RM squats, 3 x 10 RM squats and 4 x 10 RM leg presses with 2-, 3-, and 2-min recoveries, respectively. A protein-carbohydrate supplement was consumed after STS in both trials. Venous blood samples were collected before, during, and after STS and oxygen consumption before and after STS. Serum growth hormone (GH), testosterone, and free fatty acids (FFA) were significantly (P < or = 0.05) higher in P compared with PROT 5 min after an STS. The calculated area under curve (AUC) of the serum insulin response during an STS was significantly (P < 0.001) higher in PROT compared with P. The EPOC value from 90 to 120 min after an STS was significantly greater in the PROT condition compared with P (P = 0.01), and PROT treatment had a significantly higher RER 2 h postexercise (P = 0.04). The AUC of serum FFA during STS correlated significantly and negatively with RER 10-30 min after STS (r = -0.53, P = 0.02). Consuming 25 g of whey and caseinate proteins 30 min before an STS significantly decreases serum GH, testosterone, and FFA levels, and increases serum insulin during an STS. Furthermore, the pre-STS protein increased EPOC and RER significantly during 2-h recovery after STS.

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Suitable exercise for suitable persons!.

  • 07.10.2013 11:28

U Kujala, H Selänne

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Common traits in overtrained athletes and in persons with professional burn-out]. H Selänne, J Leppäluoto

  • 07.10.2013 11:20

H Selänne, J Leppäluoto

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