Daniel G. Syrotuik

Effect of concurrent strength and endurance training on skeletal muscle properties and hormone concentrations in humans

Abstract The purpose of this study was to investigate the effect of concurrent strength and endurance training on strength, endurance, endocrine status and muscle fibre properties. A total of 45 male and female subjects were randomly assigned to one of four groups; strength training only (S), endurance training only (E), concurrent strength and endurance training (SE), or a control group (C). Groups S and E trained 3 days a week and the SE group trained 6 days a week for 12 weeks. Tests were made before and after 6 and 12 weeks of training. There was a similar increase in maximal oxygen consumption (V˙O2max) in both groups E and SE (P < 0.05). Leg press and knee extension one repetition maximum (1 RM) was increased in groups S and SE (P < 0.05) but the gains in knee extension 1 RM were greater for group S compared to all other groups (P < 0.05). Types I and II muscle fibre area increased after 6 and 12 weeks of strength training and after 12 weeks of combined training in type II fibres only (P < 0.05). Groups SE and E had an increase in succinate dehydrogenase activity and group E had a decrease in adenosine triphosphatase after 12 weeks of training (P < 0.05). A significant increase in capillary per fibre ratio was noted after 12 weeks of training in group SE. No changes were observed in testosterone, human growth hormone or sex hormone binding globulin concentrations for any group but there was a greater urinary cortisol concentration in the women of group SE and decrease in the men of group E after 12 weeks of training (P < 0.05). These findings would support the contention that combined strength and endurance training can suppress some of the adaptations to strength training and augment some aspects of capillarization in skeletal muscle.

Acute creatine monohydrate supplementation: a descriptive physiological profile of responders vs. nonresponders.

&NA; Syrotuik, D.G., and G.J. Bell. Acute creatine monohydrate supplementation: a descriptive physiological profile of responders vs. nonresponders. J. Strength Cond. Res. 18(3):610–617. 2004.—The purpose of this study was to describe the physiological profile of responders (>20 mmol·kg‐1 dry weight [dw] increase in total intramuscular creatine monohydrate [Cr] + phosphorylated creatine [PCr]) versus nonresponders (<10 mmol·kg‐1 dw increase) to a 5‐day Cr load (0.3 g·kg‐1·d‐1) in 11 healthy men (mean age = 22.7 years). Pre‐post 5‐day cellular measures included total resting Cr content (Cr + PCr), fiber type composition, and fiber type cross‐sectional area (CSA) determined from muscle biopsies of the vastus lateralis. Body mass, daily dietary intake, 24‐hour urine outputs, urinary Cr and creatinine (CrN), and strength performance measures (1 repetition maximum [1RM] bench and leg press) were also assessed before and after the 5‐day loading period. Results indicated that there were 3 levels of response to the 5‐day supplementation: responders (R), quasi responders (QR), and nonresponders (NR) with mean changes in resting Cr + PCr of 29.5 mmol·kg‐1 dw (n = 3), 14.9 mmol·kg‐1 dw (n = 5), and 5.1 mmol·kg‐1 dw (n = 3), respectively. The results support a person‐by‐treatment interaction to acute Cr supplementation with R possessing a biological profile of lowest initial levels of Cr + PCr, greatest percentage of type II fibers, and greatest preload muscle fiber CSA and fat‐free mass. Responders also showed improvement in 1RM leg press scores following the 5‐day loading period. NR had higher preload levels of Cr + PCr, less type II muscle fibers, small preload muscle CSA, and lower fat‐free mass and displayed no improvements in 1RM strength scores. The results suggest that to be considered a responder to acute oral supplementation, a favorable preexisting biological profile may determine the final extent to which an individual responds to supplementation. Physiologic profiles of nonresponders appear to be different and may limit their ability to uptake Cr. This may help partially explain the reported equivocal performance findings in the Cr supplementation literature.

The effect of strength training on estimates of mitochondrial density and distribution throughout muscle fibres.

Abstract The purpose of this study was to investigate the effect of strength training (12 weeks, 3 days/week, four lower-body exercises) of young individuals (mean age 23.6 years) on estimates of mitochondrial distribution throughout muscle fibres. A control group (mean age 21.7 years) was followed simultaneously. Skeletal muscle biopsy samples were obtained from the vastus lateralis, pre- and post-training. The regional distribution of subsarcolemmal and intermyofibrillar mitochondrial populations was determined using quantitative histochemical staining of succinate dehydrogenase (SDH) in type I and II muscle fibres. Strength training resulted in significant increases of 26% and 28% in the cross-sectional area of type I and II fibres, respectively (P < 0.05). Overall SDH activity decreased by 13% with strength training (P < 0.05). The decrease in SDH activity with strength training between fibre types and between subsarcolemmal and intermyofibrillar regions of muscle fibres was not different. Fibre area and SDH activity was unchanged in the control group. We conclude that the muscle hypertrophy associated with strength training results in reduced density of regionally distributed mitochondria, as indicated by the reduction in the activity of SDH.

Examining the relationship between perfectionism and trait anger in competitive sport

Abstract The purpose of this study was to examine the relationship between athletes’ perfectionist orientations and their dispositional tendencies to experience anger in sport. A sample of 138 male teenage high‐performance Canadian Football players (M age = 18.27 years, SD = .71) completed multidimensional domain‐specific measures of perfectionism and anger in sport. Canonical correlation (R C) results revealed a profile of maladaptive perfectionism (i.e., high personal standards combined with high concern over mistakes and high perceived coach pressure) that was significantly correlated with competitive trait anger (R C = .56) and the tendency to experience anger when playing poorly (R C = .47). That is, as athletes’ levels on three perfectionism dimensions increased (i.e., personal standards, concern over mistakes, and perceived coach pressure), so did their dispositional tendencies to experience anger in sport. The benefits of conceptualizing perfectionism as a domain‐specific construct, and the importance of considering all dimensions of perfectionism simultaneously when examining the functional nature of the construct in sport are discussed

An investigation of multidimensional worry dispositions in a high contact sport

Abstract Objectives : To (a) investigate the dimensionality of competitive worry in the high contact sport of Canadian football, (b) examine the extent to which athletes were predisposed towards worrying about factors relating to personal performance failure, negative social evaluation, injury or physical danger, and situational uncertainty, and (c) determine the degree to which dispositional worry tendencies predicted pre-competitive cognitive and somatic state anxiety. Method : Male Canadian Football players ( n =170, M age=18.24 years) completed the Football Worry Scale (FWS), a football-specific version of the Collegiate Hockey Worry Scale (Dunn, J.G.H. (1999). Journal of Sport and Exercise Psychology , 21 , 259–279), to measure athletes’ dispositional tendencies to experience competitive worry across four domains. A sub-sample of athletes ( n =100) also completed the Competitive State Anxiety Inventory-2 (CSAI-2) (Martens, Burton, Vealey, Bump, & Smith (1990). Competitive anxiety in sport (pp. 117–190). Champaign, IL: Human Kinetics.) to measure pre-competitive state anxiety. Results : Confirmatory factor analyses of FWS data supported the retention of four factors to reflect the latent dimensionality of competitive worry. Repeated measures ANOVA revealed that performance failure was the most characteristic type of worry. Correlation and multiple regression analyses revealed that worry about situational uncertainties (i.e. fear of the unknown) was the strongest predictor of both somatic and cognitive state anxiety. Conclusions : Findings reinforce the importance of treating competitive worry as a multidimensional construct in future competitive sport anxiety research.

Effects of hyperbaric oxygen on recovery from exercise-induced muscle damage in humans.

ObjectiveTo determine whether hyperbaric oxygen (HBO) therapy could accelerate recovery from exercise-induced muscle damage in humans. DesignPretest–posttest design with random assignment to either a treatment (HBO) or placebo control (sham) group. SettingUniversity of Alberta and Misericordia Hospital, Edmonton. Participants12 healthy male students (24.2 ± 3.2 years) who were unaccustomed to strenuous eccentric exercise of the calf muscles. InterventionsAll subjects performed a strenuous eccentric exercise protocol designed to elicit muscle damage within the right gastrocnemius muscle. Subjects subsequently received either HBO (100% oxygen at 253 kPa [2.5 ATA] for 60 min; n = 6) or sham (atmospheric air at 132 kPa [1.3 ATA] for 60 min; n = 6) treatment conditions. The first treatment was administered 3–4 hours after damage, with a second and third at 24 and 48 hours after the first, respectively. Main Outcome MeasuresDependent variables included peak torque at 0.52 radians/s, peak isometric torque, and muscular endurance using isokinetic dynamometry; muscle cross-sectional area using magnetic resonance imaging; inorganic phosphate levels and T2 relaxation time using 31P and 1H magnetic resonance spectroscopy; pain sensation and unpleasantness using the Descriptor Differential Scale. These variables were assessed at baseline and until day 5 postdamage. ResultsThere was little evidence of a difference in recovery rate between the HBO and sham groups. Faster recovery was observed in the HBO group only for isometric peak torque and pain sensation and unpleasantness. ConclusionsHBO cannot be recommended as an effective method of treatment of this form of muscle injury.

The Effect of Inspiratory and Expiratory Respiratory Muscle Training in Rowers

This study examined inspiratory and expiratory resistive loading combined with strength and endurance training on pulmonary function and rowing performance. Twenty-one male (n = 9) and female (n = 12) rowers were matched on 2000 m simulated rowing race time and gender and randomly assigned to two groups. The experimental group trained respiratory muscles using a device that provided both an inspiratory and expiratory resistance while the control group used a SHAM device. Respiratory muscle training (RMT) or SHAM was performed 6 d/wk concurrent with strength (3 d/wk) and endurance (3 d/wk) training on alternate days for 10 weeks. Respiratory muscle training (RMT) enhanced maximum inspiratory (PImax) and expiratory (PEmax) strength at rest and during recovery from exercise (P < 0.05). Both groups showed improvements in peak VO2, strength, and 2000 m performance time (P < 0.05). It was concluded that RMT is effective for improving respiratory strength but did not facilitate greater improvements to simulated 2000 m rowing performance.

Effects of creatine monohydrate supplementation on body composition and strength indices in experienced resistance trained women.

The purpose of this study was to examine 10 weeks of creatine monohydrate (Cr) supplementation coupled with resistance training on body composition and strength in women trainees. Twenty-six subjects ingested Cr (n = 13) or a placebo (Pl) (n = 13) at a dose of 0.3 g·kg−1 and 0.03 g·kg−1 body mass for the initial 7 days and subsequent 9 weeks, respectively, while performing a resistance training program 4 days per week. Significant increases (p < 0.05) occurred in both groups for lean body mass and 1 repetition maximum (1RM) bench press and incline leg press. There was a significant main effect for training, but there was no significant difference in the total number of repetitions completed after 5 sets of multiple repetitions to exhaustion at 70% of 1RM for bench press and incline leg press for both groups or in the ability to perform a greater training volume (sets × repetitions × load) in the Cr vs. Pl groups over the 10 weeks. The results indicate that Cr supplementation combined with 10 weeks of concurrent resistance training may not improve strength or lean body mass greater than training only. These findings may be a result of nonresponders due to gender differences or a varying biological potential to uptake Cr within the muscle.

Adaptive responses to creatine loading and exercise in fast-twitch rat skeletal muscle

We investigated the effects of chronic creatine loading and voluntary running (Run) on muscle fiber types, proteins that regulate intracellular Ca2+, and the metabolic profile in rat plantaris muscle to ascertain the bases for our previous observations that creatine loading results in a higher proportion of myosin heavy chain (MHC) IIb, without corresponding changes in contractile properties. Forty Sprague-Dawley rats were assigned to one of four groups: creatine-fed sedentary, creatine-fed run-trained, control-fed sedentary, and control-fed run-trained animals. Proportion and cross-sectional area increased 10% and 15% in type IIb fibers and the proportion of type IIa fibers decreased 11% in the creatine-fed run-trained compared with the control-fed run-trained group (P < 0.03). No differences were observed in fast Ca2+-ATPase isoform SERCA1 content (P > 0.49). Creatine feeding alone induced a 41% increase (P < 0.03) in slow Ca2+-ATPase (SERCA2) content, which was further elevated by 33% with running (P < 0.02). Run training alone reduced parvalbumin content by 50% (P < 0.05). By comparison, parvalbumin content was dramatically decreased by 75% (P < 0.01) by creatine feeding alone but was not further reduced by run training. These adaptive changes indicate that elevating the capacity for high-energy phosphate shuttling, through creatine loading, alleviates the need for intracellular Ca2+ buffering by parvalbumin and increases the efficiency of Ca2+ uptake by SERCAs. Citrate synthase and 3-hydroxyacyl-CoA dehydrogenase activities were elevated by run training (P < 0.003) but not by run training + creatine feeding. This indicates that creatine loading during run training supports a faster muscle phenotype that is adequately supported by the existing glycolytic potential, without changes in the capacity for terminal substrate oxidation.

Physiological demands of women’s rugby union: time–motion analysis and heart rate response

Abstract The aim of this study was to determine the physical demands of women’s rugby union match play using time–motion analysis and heart rate (HR) response. Thirty-eight premier club level female rugby players, ages 18–34 years were videotaped and HRs monitored for a full match. Performances were coded into 12 different movement categories: 5 speeds of locomotion (standing, walking, jogging, striding, sprinting), 4 forms of intensive non-running exertion (ruck/maul/tackle, pack down, scrum, lift) and 3 discrete activities (kick, jump, open field tackle). The main results revealed that backs spend significantly more time sprinting and walking whereas forwards spend more time in intensive non-running exertion and jogging. Forwards also had a significantly higher total work frequency compared to the backs, but a higher total rest frequency compared to the backs. In terms of HR responses, forwards displayed higher mean HRs throughout the match and more time above 80% of their maximum HR than backs. In summary, women’s rugby union is characterised by intermittent bursts of high-intensity activity, where forwards and backs have similar anaerobic energy demands, but different specific match demands.