Male Rowers Research Articles

Circulating IGF‐I levels are associated with increased biventricular contractility in top‐level rowers

The intensive physical activity is often associated with cardiac changes. (i) To evaluate the IGF-I system and myocardial structure and function by standard Doppler echocardiography and Tissue Doppler in athletes and sedentary controls; and (ii) to determine any relationship between IGF-I system and echocardiographic parameters. Nineteen male top-level rowers and 19 age-matched healthy sedentary male controls underwent blood determination of fasting serum IGF-I, IGFBP-3 and acid-labile subunit levels and standard Doppler echocardiography combined with pulsed Tissue Doppler of posterior septal wall, left ventricular (LV) lateral mitral annulus and right ventricular (RV) tricuspid annulus. Myocardial presystolic (PS(m)), systolic (S(m)), the ratio of early diastolic (E(m)) to atrial (A(m)) velocities as well as myocardial time intervals were calculated. Rowers had higher serum IGF-I levels (P = 0.04), higher biventricular cavity dimensions and wall thicknesses compared to controls. They also had better LV and RV myocardial function than controls. In the rowers, IGF-I was associated with LV ejection fraction (r = 0.50, P = 0.03), RV PS(m) velocity (r = 0.55, P = 0.01) and with RV myocardial precontraction time (r = -0.57, P = 0.01). These associations remained significant after adjusting for age and heart rate. Top-level athletes showed higher IGF-I levels and a better myocardial performance than controls, particularly for the RV systolic activity. The independent correlations between IGF-I and systolic parameters of the left (ejection fraction) and right (PS(m) velocity and precontraction time) ventricles may possibly indicate a role of IGF-I system in the modulation of myocardial inotropism in athletes. Further studies are needed to confirm this hypothesis.

Do men and women row differently? a spinal kinematic and force perspective

Performance differences have been noted between male and female rowers; the aim of this study was to determine if these are due to differences in rowing technique. An electromagnetic motion measurement device in conjunction with a load cell was used to compare the ergometer rowing kinematics of female and male elite national rowers. Male rowers generated significantly greater peak force during the stroke, ( p < 0.0001) and greater power. Although there was no difference in stroke length, females demonstrated a more optimal lumbopelvic rhythm due to a greater anterior pelvic rotation during the stroke ( p < 0.05). This is likely to account for the lack of difference in stroke length. In conclusion, gender differences do exist in kinematic parameters of rowing technique. With a greater mass and height, the male athletes are more powerful than the females; however, females appear to optimize their kinematics in an attempt to enhance performance.

Elderly Oarsmen Have Larger Major Psoas Muscle Mass

Knee extensor muscle (KE) and major psoas muscle (MP) of trunk play a decisive role in walking, stair ascent/descent, and so on in humans. Particularly, it is important for elderly people to prevent the weakness of these muscles to enhance quality of life. Rowing consists of rhythmical muscle contractions in both the lower and upper body, and demands a high aerobic capacity (Secher et al., 1983). Early study suggested that rowing prevents the wasting of leg extensor muscle in elderly men (Yoshiga et al., 2002), whereas no information is available on MP in elderly rowers. PURPOSE: For the purpose of examining the preventive effect of rowing on MP mass, in the present study, we compared MP mass and trunk flexion force in elderly male rowers with age-matched untrained men. METHODS: Participants were 22 elderly rowing trained men (RT; age: 67.5±2.5 yrs, height: 172.0±4.8 cm, body mass: 69.4±7.0 kg, Fat Free Mass (FFM): 55.9± 3.7 kg, VO2peak:37.6±6.3 mL/kg/min, mean±SD) and 19 untrained elderly men(UT:66.0±2.5 yrs, 164.7±4.2 cm, 63.4±8.1 kg, 49.7 ± 4.8 kg, 28.7 ± 5.7 mL/kg/min). Muscle cross-sectional area (CSA) was measured on MP and KE by magnetic resonance imaging, and bilateral leg extension power and trunk flexion force were measured. RESULTS: The CSAs of MP and KE in RT were significantly larger by 45% and 15% than those in UT, respectively (RT vs UT; MP: 30.2±5.2 vs 20.9±4.3 cm2, p < 0.001. KE: 120.7±15.6 vs 105.1±17.7 cm2, p < 0.01). MP CSA per FFM of RT was 29% higher than that of UT (RT: 0.54±0.09 vs UT: 0.42±0.08 cm2/kgFFM, p<0.001), while there was no significant difference between the two groups in KE CSA per FFM (RT: 2.15±0.2 vs UT: 2.11±0.25 cm2/kgFFM). Compared with UT, RT had higher leg extension power (W, W/cm2CSA) by 42%, 23% (RT vs UT; 1256±247 vs 887±219 W, 10.4±1.5 vs 8.4±1.6 W/cm2CSA, p<0.001, respectively). Trunk flexion force in RT was also 44% higher than that in UT (RT: 421±56 vs UT: 292±57 N, p<0.001), but in trunk force expressed by N/cm2CSA, no significant difference was observed between the two groups (RT: 14.2±2.1 vs UT: 14.3±3.0 N/cm2CSA). CONCLUSIONS: These results provide possibility that rowing exercise prevents the wasting and weakness of major psoas muscle in elderly men.

Hormonal Responses To A Period Of Training And Recovery In Trained Male Rowers

Hormonal Responses To A Period Of Training And Recovery In Trained Male Rowers

Acute Effects of Different Whole-Body Vibration Frequencies and Amplitudes on Muscle Activity in Rowers

PURPOSE: To investigate the effects of an acute Whole-Body Vibration (WBV) on the muscle activity and performance during the 30-s Wingate test on a rowing ergometer. METHODS: Fourteen elite male rowers (height, 175.6±4.7 cm; body mass, 76.4±5.2 kg) were administered in a randomized cross-over design into four experiments including the high-frequency high-amplitude (HFHA, 30 Hz and 0.6 mm), low-frequency low-amplitude (LFLA, 15 Hz and 0.375 mm), high-frequency low-amplitude (HFLA, 30 Hz and 0.375 mm) and non-vibration exercise (Con). Isometric maximum voluntary contraction (IMVC) of knee extensors and flexors were collected before the treatments, and then the athletes completed the 30-s Wingate test on the rowing ergometer immediately after the vibration or no vibration stimulation (10×1 min, 1 min rest interval). The muscle activities of the thigh were measured via the surface electromyography (EMG) and the power output was recorded by the rowing ergometer. The repeated one-way ANOVA for four treatments was calculated to determine the statistical differences. RESULTS: There were no significant differences on the EMG root-mean-square (EMGrms), integral EMG (IEMG) and average EMG (aEMG) of the right thigh (dominant leg) among the four treatments (p>0.05). However, the HFLA had significantly higher EMGrms (95.69±24.80 %) and the IEMG (18.03±4.95 %) in the vastus lateralis of the left leg (non-dominant leg) at the peak power output than the HFHA (EMGrms, 80.61±15.65 %; IEMG, 14.47±5.55 %, p<0.05) and the Con (EMGrms, 79.45±12.48 %; IEMG, 15.17±3.10 %, p<0.05), and the aEMG was notably increased in HFLA (82.88±23.19 %) compared with the HFHA (69.27±14.43 %), LFLA (71.15±19.90 %) and Con (68.71±11.68 %) (p<0.05). Moreover, the HFHA (25.23±6.25 μV/W/kg) had a tendency to improve the EMGrms/peak mechanical power compared with the Con (30.15±9.10 ìV/W/kg, p=0.05). CONCLUSIONS: This study exhibited that acute WBV could not improve the anaerobic exercise performance, and the HFLA treatment might reduce the working efficiency of motor units on the non-dominant leg during the anaerobic power test in elite male rowers.

Testosterone and BMD in Elite Male Lightweight Rowers

The purpose of the present study was to investigate if a relationship between BMD and testosterone levels could be identified in elite male lightweight rowers. Thirteen male lightweight national team rowers had their BMD measured in a DEXA scanner. Plasma concentrations of total testosterone (TT), free testosterone (FT), dihydrotestosterone (DHT) and sex hormone binding globulin (SHBG) and additional parameters related to bone metabolism were measured. Plasma concentrations of TT, FT and DHT were in the lower part of the normal range, while BMD was close to or above normal. BMD of total body and L2 - L4 were correlated to years of training (r (s): 0.59, p = 0.034 and r (s): 0.73, p = 0.005) and to TT (r (s): 0.56, p = 0.046 and rs: 0.63, p = 0.021). Moreover, L2 - L4 BMD was correlated to FT (r (s): 0.62, p = 0.024). After adjusting for years of training, partial correlation analysis showed a significant correlation between L2 - L4 BMD and TT (r (s): 0.61, p < 0.05). BMD appears to be influenced by both testosterone levels and years of training in elite male lightweight rowers. The relatively high BMD and low testosterone levels indicate that the mechanical loading induced by rowing is more important to BMD than testosterone levels. Prospective investigations are needed to elucidate potential causal relationships.

Alternative method for determining anaerobic threshold in rowers

In rowing, the standard breathing that athletes are trained to use makes it difficult, or even impossible, to detect ventilatory limits, due to the coupling of the breath with the technical movement. For this reason, some authors have proposed determining the anaerobic threshold from the respiratory exchange ratio (RER), but there is not yet consensus on what value of RER should be used. The objective of this study was to test what value of RER corresponds to the anaerobic threshold and whether this value can be used as an independent parameter for determining the anaerobic threshold of rowers. The sample comprised 23 male rowers. They were submitted to a maximal cardiorespiratory test on a rowing ergometer with concurrent ergospirometry in order to determine VO2max and the physiological variables corresponding to their anaerobic threshold. The anaerobic threshold was determined using the Dmax (maximal distance) method. The physiological variables were classified into maximum values and anaerobic threshold values. The maximal state of these rowers reached VO2 (58.2±4.4 ml.kg-1.min-1), lactate (8.2±2.1 mmol.L-1), power (384±54.3 W) and RER (1.26±0.1). At the anaerobic threshold they reached VO2 (46.9±7.5 ml.kg-1.min-1), lactate (4.6±1.3 mmol.L-1), power (300± 37.8 W) and RER (0.99±0.1). Conclusions - the RER can be used as an independent method for determining the anaerobic threshold of rowers, adopting a value of 0.99, however, RER should exhibit a non-linear increase above this figure.

Método alternativo de determinação de limiar anaeróbio em remadores

In rowing, the standard breathing that athletes are trained to use makes it difficult, or even impossible, to detect ventilatory limits, due to the coupling of the breath with the technical movement. For this reason, some authors have proposed determining the anaerobic threshold from the respiratory exchange ratio (RER), but there is not yet consensus on what value of RER should be used. The objective of this study was to test what value of RER corresponds to the anaerobic threshold and whether this value can be used as an independent parameter for determining the anaerobic threshold of rowers. The sample comprised 23 male rowers. They were submitted to a maximal cardiorespiratory test on a rowing ergometer with concurrent ergospirometry in order to determine VO2máx and the physiological variables corresponding to their anaerobic threshold. The anaerobic threshold was determined using the Dmax (maximal distance) method. The physiological variables were classified into maximum values and anaerobic threshold values. The maximal state of these rowers reached VO2 (58.2±4.4 ml.kg-1.min-1), lactate (8.2±2.1 mmol.L-1), power (384±54.3 W) and RER (1.26±0.1). At the anaerobic threshold they reached VO2 (46.9±7.5 ml.kg-1.min-1), lactate (4.6±1.3 mmol.L-1), power (300± 37.8 W) and RER (0.99±0.1). Conclusions - the RER can be used as an independent method for determining the anaerobic threshold of rowers, adopting a value of 0.99, however, RER should exhibit a non-linear increase above this figure.

APPLICATION OF SURFACE ELECTROMYOGRAPHY IN ASSESSING MUSCLE RECRUITMENT PATTERNS IN A SIX-MINUTE CONTINUOUS ROWING EFFORT

Specific sequences of muscle coordination exist in movements of every sport. In particular, sports involving repetitive movement patterns such as rowing may rely more heavily on coordinated muscle contraction sequencing in order to produce optimal performance. The aim of this study was to monitor the fatigue patterns of the major muscles engaged during the rowing stroke in rowers of varying abilities during a 6-minute continuous maximal rowing effort on a Concept II rowing ergometer. Sixteen male rowers were categorized into 5 groups based on years of training and their average pace of the 6-minute continuous maximal rowing effort. Continuous surface electromyography signals, recorded from brachioradialis, biceps brachii, middeltoid, rectus abdominis, erector spinae, rectus femoris, biceps femoris, and medial gastrocnemius, were used to investigate the influence of local muscle fatigue on optimal muscle coordination sequences during the rowing exercise. Rowers who performed better on the ergometer test and had more rowing experience tended to portray muscle recruitment patterning, which alternately emphasized different major muscle groups in a form of sharing of workload. This sharing allowed mean peak frequency restitution to take place in some muscles, while others took on more of the workload. The muscles of rowers with less experience and lower levels of performance did not appear to exhibit this same phenomenon known as biodynamic compensation. If coaches have a clearer picture of the fatigue patterns and recruitment strategies occurring in their athletes during a maximal effort row, strength training program adaptations could be made to compensate for weaker areas, which may assist rowers in attaining and sustaining more optimal patterns and strategies throughout the exercise effort.

Effect of Prolonged Training Period on Plasma Adiponectin in Elite Male Rowers

Adiponectin is secreted by adipocytes and has been implicated in the regulation of energy homeostasis. Vigorous training program represents a physical stress condition in which heavy changes in energy expenditure might increase adiponectin concentration in athletes. Therefore, the aim of the present study was to investigate if there are changes in fasting adiponectin concentration during preparatory period in elite male rowers. Twelve rowers (mean and SD; age: 20.8+/-3.0 years; height: 192.9+/-4.7 cm; body mass: 91.9+/-5.3 kg; body fat percentage: 11.9+/-1.4%) were tested seven times over a 24-week training season. In addition to adiponectin, leptin, insulin, growth hormone, and glucose values were evaluated. Maximal oxygen consumption (VO (2 max)) and aerobic power (Pa (max)) were determined before and after the training period. Training was mainly organized as low-intensity prolonged training. Significant increases in VO (2 max) (by 3.2+/-1.8%; from 6.2+/-0.5 to 6.4+/-0.4 l/min), VO (2 max/kg) (by 2.2+/-2.0%; from 67.9+/-3.0 to 69.4+/-3.0 ml/min/kg) and Pa (max) (by 4.6+/-6.3%; from 444.6+/-39.1 to 465.8+/-25.0 W) were observed after the 24-week period. All measured body compositional values were similar to pretraining values after the training period. Fasting adiponectin did not change during the preparatory period. Likewise, leptin, insulin, growth hormone, and glucose values were not significantly changed after the training period. Adiponectin concentration was significantly correlated (all p<0.05) with body mass (r=-0.40), body fat mass (r=-0.33), body fat free mass (r=0.38), and leptin (r=-0.31) values. In conclusion, fasting adiponectin does not change throughout the prolonged training period in elite male rowers despite substantial changes in training volume. Further studies are needed to clarify possible mechanisms by which adiponectin might influence energy homeostasis during heavy training in elite athletes.

Predicting the 1000 m rowing ergometer performance in 12–13-year-old rowers: The basis for selection process?

Performance-predictive parameters have been established for rowers representing different quality levels, sexes, weight categories and classifications, but none have been designed for very young rowers (age <14). The objective of this study was to predict 1000-m rowing ergometer performance based on 12 anthropometric and six physiological variables in 48 male rowers (age range 12.0-13.9 year; mean+/-S.D. 12.94+/-0.61) and to determine the key parameters that would perhaps provide a scientific basis for talent identification and the selection process in rowing. The subjects completed an incremental maximal treadmill test. Their body height (r=-0.79), body mass (r=-0.60), lean body mass (r=-0.82), leg length (r=-0.72), arm length (r=-0.71), bicristal diameter (r=-0.63), biacromial diameter (r=-0.73), upper arm girth (r=-0.34), forearm girth (r=-0.63), thigh girth (r=-0.29), calf girth (r=-0.54), maximal oxygen uptake (in L/min, r=-0.89; and in mL/kg/min, r=-0.36), maximal ventilation (r=-0.77), and oxygen uptake at ventilatory anaerobic threshold (r=-0.87) correlated with 1000-m time (p<0.05), while percent body fat, percent of maximal oxygen uptake at ventilatory anaerobic threshold and maximal lactate did not. Performance correlated significantly with age (r=-0.46; p<0.01), so it was important to consider this effect in the resulting regression models. Multiple regression procedures indicated that the model comprising anthropometric and physiological variables combined best predicts performance (R(2)=0.85), followed by models that comprised physiological (R(2)=0.80) and anthropometric (R(2)=0.76) variables alone. In conclusion, in rowers aged 12-13 year a higher aerobic capacity (as measured by maximal oxygen uptake in L/min), and a larger body size are beneficial for performance over 1000-m rowing ergometer distance.

Plasma Ghrelin Is Altered After Maximal Rowing Exercise In Elite Male Athletes

The information of the regulatory effect of ghrelin on growth hormone release as a result of acute physical exercise is limited. To our knowledge, no studies have yet investigated the effect of short term maximal exercise on plasma ghrelin using an exercise protocol in which all major muscle groups are involved. This may cause additional energy expenditure that may be needed for plasma ghrelin to be reduced by acute exercise. PURPOSE: To investigate plasma ghrelin response to acute rowing ergometer exercise in elite male rowers. METHODS: Eight rowers performed a maximal 6,000-m rowing ergometer test (mean performance time 19 min 52 s; 1192.1±16.4 s), and venous blood samples were obtained before, immediately after and after 30 min of recovery. In addition to ghrelin concentration, leptin, insulin, growth hormone, insulin-like growth factor-1 (IGF-1), testosterone, cortisol and glucose values were measured. RESULTS: Ghrelin was significantly increased immediately after the exercise (+24.4%; p<0.05) and was decreased during the first 30 min of recovery (−17.5%; p>0.05) compared to the post-exercise level. Leptin was significantly decreased immediately after the exercise and remained significantly decreased after the first 30 min of recovery. No changes occurred in insulin concentrations. While growth hormone, IGF-1 and testosterone values were significantly increased and decreased to the pre-exercise level immediately after the exercise and after the first 30 min of recovery, respectively. Cortisol and glucose values were significantly increased immediately after the exercise and remained significantly increased during the first 30 min of recovery. There were no relationships between plasma ghrelin and other measured blood parameters after the exercise, nor were changes in ghrelin related to changes in other measured blood biochemical values after the exercise. CONCLUSION: These results suggest that acute negative energy balance induced by maximal short-term exercise elicits a metabolic response with opposite changes in ghrelin and leptin concentrations in elite male athletes.

Force-Velocity and Power-Velocity Relationships during Maximal Short-Term Rowing Ergometry

Maximal rowing power-velocity relationships that exhibit ascending and descending limbs and a local maximum have not been reported. Further, duty cycle (portion of the stroke occupied by the pull phase) is unconstrained during rowing and is known to influence average muscular power output. Our purposes for conducting this study were to fully describe maximal short-term rowing force-velocity and power-velocity relationships. Within the context of those purposes, we also aimed to determine the apex of the power-velocity relationship and the influence of freely chosen duty cycle on stroke power. Collegiate varsity male rowers (N = 11, 22.9 +/- 2.3 yr, 84.1 + 12.1 kg, 184 +/- 7 cm) performed five maximal rowing trials using an inertial load ergometer. For each stroke, we determined force and power averaged for the pull phase and the complete stroke, instantaneous peak force and power, average handle velocity for the pull phase, handle velocity at peak instantaneous force and power, pull time, recovery time, and freely chosen duty cycle. Force-velocity and power-velocity relationships were characterized using regression analyses, and optimal velocities were determined from the regression coefficients. Pull force-velocity (r2 = 0.99) and peak instantaneous force-velocity (r2 = 0.93) relationships were linear. Stroke power (r2 = 0.98), pull power (r2 = 0.99), and instantaneous peak power (r2 = 0.99) were quadratic, with apexes at 2.04, 3.25, and 3.43 m x s(-1), respectively. Maximum power values were 812 +/- 28 W (9.8 +/- 0.4 W x kg(-1)), 1995 +/- 67 W (23.9 +/- 0.7 W x kg(-1)), and 3481 +/- 112 W (41.9 +/- 1.3 W x kg(-1)) for stroke, pull, and instantaneous power, respectively. Freely chosen duty cycle decreased from 58 +/- 1% on the first stroke to 26 +/- 1% on the fifth stroke. These data characterized the maximal rowing force-velocity and power-velocity relationships and identified the optimal velocity for producing maximal rowing power. Differences in maximum pull and stroke power emphasized the importance of duty cycle.

Olympic lightweight and open-class rowers possess distinctive physical and proportionality characteristics

Rowers competing at the 2000 Olympic Games were measured for 38 anthropometric dimensions. The aim was to identify common physical characteristics that could provide a competitive advantage. The participants included 140 male open-class rowers, 69 female open-class rowers, 50 male lightweight rowers, and 14 female lightweight rowers. Body mass, stature, and sitting height were different (P < 0.01) between the open-class and lightweight rowers, as well as a comparison group of healthy young adults (“non-rowers”, 42 males, 71 females), for both sexes. After scaling for stature, the open-class rowers remained proportionally heavier than the non-rowers, with greater proportional chest, waist, and thigh dimensions (P < 0.01). Rowers across all categories possessed a proportionally smaller hip girth than the non-rowers (P < 0.01), which suggested the equipment places some constraints on this dimension. Top-ranked male open-class rowers were significantly taller and heavier and had a greater sitting height (P < 0.01) than their lower-ranked counterparts. They were also more muscular in the upper body, as indicated by a larger relaxed arm girth and forearm girth (P < 0.01). For the male lightweight rowers, only proportional thigh length was greater in the best competitors (P < 0.01). In the female open-class rowers, skinfold thicknesses were lower in the more highly placed competitors (P < 0.01). In conclusion, the rowers in this sample demonstrated distinctive physical characteristics that distinguish them from non-rowers and other sports performers.

Influence of Nutrient Intake after Weigh-In on Lightweight Rowing Performance

The aim of the present study was to compare the effectiveness of different nutritional recovery strategies between weigh-in and racing on 2000-m rowing ergometer performance among oarsmen undertaking short-term weight loss before competition. Competitive rowers (N = 12) completed four ergometer trials, each separated by 48 h. No weight restrictions were imposed for the first trial (TR1). Thereafter, athletes were required to reduce their body mass by 5.2% in the 24 h before trial 2 (TR2), again reaching this body mass before the final two trials (TR3 and TR4). Athletes were provided with one of three nutritional recovery strategies in the 2 h between weigh-in and racing in a counterbalanced fashion according to a Latin square design: fluid (2.8 kJ.kg(-1), 0.0 g.kg(-1) carbohydrate, 0.6 mg.kg(-1) sodium, 28.5 mL.kg(-1) fluid; FLU), carbohydrate/sodium (45.3 kJ.kg(-1), 2.2 g.kg(-1) carbohydrate, 32.9 mg.kg(-1) sodium, 7.2 mL.kg(-1) fluid; CHO), and a combination of water and carbohydrate/sodium (44.8 kJ.kg(-1), 2.3 g.kg(-1) carbohydrate, 33 mg.kg(-1) sodium, 28.5 mL.kg(-1) fluid; COM). Performance was slower for CHO compared with both COM (mean difference, 4.13; 95% CI, 1.37-6.88 s; P = 0.003) and FLU (2.88; 95% CI, 0.13-5.63 s; P = 0.039). However, FLU was not significantly slower than COM (1.24; 95% CI, -1.41 to 3.90 s; P = 0.474). The present investigation has shown that although carbohydrate and sodium intake may be important in the recovery period between weigh-in and 2000-m rowing ergometer performance, fluid intake has a greater influence on performance among lightweight male rowers who undertake short-term weight loss to achieve specified body-mass limits.

Application of Surface Electromyography in Assessing Muscle Recruitment Patterns in a Six-Minute Continuous Rowing Effort

Specific sequences of muscle coordination exist in movements of every sport. In particular, sports involving repetitive movement patterns such as rowing may rely more heavily on coordinated muscle contraction sequencing in order to produce optimal performance. The aim of this study was to monitor the fatigue patterns of the major muscles engaged during the rowing stroke in rowers of varying abilities during a 6-minute continuous maximal rowing effort on a Concept II rowing ergometer. Sixteen male rowers were categorized into 5 groups based on years of training and their average pace of the 6-minute continuous maximal rowing effort. Continuous surface electromyography signals, recorded from brachioradialis, biceps brachii, middeltoid, rectus abdominis, erector spinae, rectus femoris, biceps femoris, and medial gastrocnemius, were used to investigate the influence of local muscle fatigue on optimal muscle coordination sequences during the rowing exercise. Rowers who performed better on the ergometer test and had more rowing experience tended to portray muscle recruitment patterning, which alternately emphasized different major muscle groups in a form of sharing of workload. This sharing allowed mean peak frequency restitution to take place in some muscles, while others took on more of the workload. The muscles of rowers with less experience and lower levels of performance did not appear to exhibit this same phenomenon known as biodynamic compensation. If coaches have a clearer picture of the fatigue patterns and recruitment strategies occurring in their athletes during a maximal effort row, strength training program adaptations could be made to compensate for weaker areas, which may assist rowers in attaining and sustaining more optimal patterns and strategies throughout the exercise effort.

Plasma ghrelin responses to acute sculling exercises in elite male rowers

The regulatory effect of ghrelin on growth hormone (GH) is limited in describing ghrelin response to acute submaximal exercise intensities in elite athletes. We investigated the effects of a single sculling exercise performed above and below the individual anaerobic threshold (IAT) on total ghrelin concentration in highly trained male rowers. Nine elite male rowers (20.1 +/- 3.7 years; 190.0 +/- 5.2 cm; 89.6 +/- 4.6 kg; %body fat: 9.9 +/- 2.5%) volunteered for this study. Single scull rowing was performed below and above IAT using a mean of 5 bpm above and below the heart rate of the IAT during graded exercise test. Ghrelin, leptin, GH, insulin, and glucose were measured before, immediately after, and after 30 min of recovery. Plasma ghrelin concentration did not increase significantly in either exercise but was approaching significance after 30 min of recovery (P = 0.051) when the constant load sculling was performed at the intensity above the IAT. There were no changes in plasma leptin levels. GH increased significantly immediately after exercise and remained elevated during the 30 min of recovery in both exercise conditions, while insulin decreased significantly immediately after exercise and remained significantly lower after the 30 min of recovery in both exercise intensities. Baseline ghrelin was not correlated with the body composition, physical performance, or blood biochemical data. There was no significant relationship between plasma ghrelin and other blood variables immediately after the 30 min of recovery in both exercise tests and changes in ghrelin were not related to blood biochemical variables after the exercise tests. The acute constant load sculling exercise above or below IAT that increased GH concentrations did not significantly increase the circulating plasma ghrelin levels.

The influence of inspiratory and expiratory muscle training upon rowing performance

We investigated the effect of 4 week of inspiratory (IMT) or expiratory muscle training (EMT), as well as the effect of a subsequent 6 week period of combined IMT/EMT on rowing performance in club-level oarsmen. Seventeen male rowers were allocated to either an IMT (n = 10) or EMT (n = 7) group. The groups underwent a 4 week IMT or EMT program; after interim testing, both groups subsequently performed a 6 week program of combined IMT/EMT. Exercise performance and physiological responses to exercise were measured at 4 and 10 week during an incremental rowing ergometer 'step-test' and a 6 min all-out (6MAO) effort. Pressure threshold respiratory muscle training was undertaken at the 30 repetition maximum load (approximately 50% of the peak inspiratory and expiratory mouth pressure, P (Imax) or P (Emax), respectively). P (Imax) increased during the IMT phase of the training in the IMT group (26%, P < 0.001) and was accompanied by an improvement in mean power during the 6MAO (2.7%, P = 0.015). Despite an increase in P (Emax) by the end of the intervention (31%, P = 0.03), the EMT group showed no significant changes in any performance parameters during either the 'step-test' or 6MAO. There were no significant changes in breathing pattern or the metabolic response to the 6MAO test in either group, but the IMT group showed a small decrease in HR (2-5%, P = 0.001). We conclude that there were no significant additional changes following combined IMT/EMT. IMT improved rowing performance, but EMT and subsequent combined IMT/EMT did not.

The relationships between hamstring flexibility, lumbar flexion, and low back pain in rowers

In this study, we examined the relationships between low back pain, hamstring flexibility, and lumbar flexion in rowers. Twenty-six male university rowers participated. Hamstring flexibility was assessed using an adjusted straight leg raise technique, and lumbar flexion was assessed via a distraction of skin marks protocol while long sitting. A questionnaire ascertained rowing details and low back pain characteristics. Low back pain was highly prevalent. No association was observed between low back pain and hamstring flexibility, or between hamstring flexibility and lumbar flexion. Sufferers of low back pain showed reduced lumbar flexion (P=0.03; 95% confidence interval = − 3.7 to −0.2). Results obtained using the adjusted straight leg raise technique suggested that low back pain was not associated with hamstring inflexibility, which suggests that increasing hamstring flexibility for rehabilitation or prevention of low back pain in rowers might not be necessary.

ELECTROMYOGRAPHIC AND NEUROMUSCULAR FATIGUE THRESHOLDS AS CONCEPTS OF FATIGUE

The aim of this study was to investigate the concepts of electromyographic (EMG) threshold (EMGT) by integrated EMG (iEMG) signals and neuromuscular fatigue threshold (NMFT) concepts in trained male athletes. Nine competitive national-level male rowers (21.8 ± 4.4 years; 186.2 ± 4.6 cm; 79.6 ± 8.4 kg) took part in this investigation. Subjects were asked to participate in the graded exercise test to volitional exhaustion and 500-, 1,000-, and 2,000-m all-out rowing ergometer tests on a rowing ergometer. During all tests, oxygen consumption parameters, average power, and iEMG of the musculus vastus lateralis were recorded. The second ventilatory threshold (248.9 ± 26.67 W) and EMGT (258.89 ± 27.13 W) were not significantly different but were significantly lower than the NMFT (302.25 ± 45.10 W). During 1,000- and 2,000-m all-out distances, O2 increased during the first minute and then leveled on a plateau with a slight decrease at the end of the exercise. Vastus lateralis activity showed a slight increase during all distances that was accompanied by a remarkable increase towards the end of the distance. All measured threshold values were significantly correlated (r < 0.70; p > 0.05) to the rowing ergometer performance characteristics. It was concluded that EMGT is closely related to the aerobic-anaerobic transition phase, because NMFT represents the local fatigue accumulation in the muscle. NMFT indicates the performance capacity of the muscles; therefore, it helps coaches to better predict top athletes' performance.