Effect of applied cadence in repeated sprint cycling on muscle characteristics.

PURPOSE: This study aimed to investigate physiological responses, muscle-tendon unit properties of the quadriceps muscle, and mechanical performance after repeated sprint cycling at optimal and 70% of optimal cadence. METHODS: Twenty recreational cyclists performed as first sprint performance cycling test and during subsequent sessions two repeated sprint cycling protocols at optimal and 70% of optimal cadence, in random order. The muscle-tendon unit outcome measures on the dominant leg included muscle thickness, fascicle length (Lf), pennation angle (θp), and stiffness for the rectus femoris (RF), vastus lateralis (VL), and vastus medialis muscle (VM) at baseline, immediately after repeated sprint cycling, and 1-h post-exercise. RESULTS: The results showed an increase in muscle thickness and θp in RF, VL, and VM for both cadences from baseline to immediately after exercise. The Lf decreased in RF (both cadences), while stiffness decreased in RF, VL, and VM at optimal cadence, and in VL at 70% of optimal cadence from baseline to immediately after exercise. CONCLUSION: The present study revealed that the alterations in muscle characteristics were more marked after repeated sprint cycling at optimal cadence compared with a lower cadence most likely as a result of higher load on the muscle-tendon unit at optimal cadence.

Optimal and freely chosen paddling rate during moderate kayak ergometry.

Moderate paddling, as in long distance kayaking, constitutes an endurance activity, which shares energetic aspects with activities such as long distance running and road cycling. The aim of the present study was to investigate whether in moderate paddling there is a U-shaped relationship between oxygen uptake and stroke rate, and also whether elite kayakers apply a freely chosen stroke rate, which is energetically optimal. Eleven young male elite kayakers performed moderate kayak ergometry at preset target stroke rates of 65, 75, and 90 strokes min-1, and at a freely chosen stroke rate, while physiological responses including oxygen uptake were measured. The results showed that considering average values calculated across all participants, there was an approximately U-shaped relationship between oxygen uptake and target stroke rate with a minimum at 75 strokes min-1. The freely chosen stroke rate was 67.0 ± 6.1 strokes min-1. Thus, the freely chosen stroke rate, for the group in total, appeared to be lower and require higher oxygen uptake as compared to the energetically optimal preset target stroke rate. Eight out of 11 participants had a higher oxygen uptake (5.1% ± 6.7%, p = 0.028, across all participants) at their freely chosen stroke rate than at the preset target stroke rate, which resulted in the lowest oxygen uptake. In conclusion, an approximately U-shaped relationship between oxygen uptake and stroke rate for young elite kayakers during moderate ergometer kayaking was found. Additionally, the freely chosen stroke rate was systematically lower and, consequently, required higher oxygen uptake than the preset stroke rate, which resulted in the lowest oxygen uptake.

Freely chosen cadence during ergometer cycling is dependent on pedalling history.

PURPOSE: History dependence can refer to the fact that parts of the human physiology (e.g., one or a group of muscles, or the nervous system) as well as functional aspects of the human (e.g., motor behaviour, or performance) depend on prior muscle activation. In the present study, it was investigated whether initial cycling at relatively low and high preset target cadences affected a subsequent freely chosen cadence at the end of the same bout of submaximal ergometer cycling. METHODS: Twenty-two participants performed a single test session, which consisted of separate bouts of submaximal ergometer cycling. In one bout, cycling at 50 rpm was followed by cycling at freely chosen cadence. In another bout, cycling at 90 rpm was followed by cycling at freely chosen cadence. In yet another bout (denoted reference), the cadence was freely chosen throughout. Behavioural (cadence), biomechanical (tangential pedal force), and physiological (heart rate) responses were measured. RESULTS: Increased cadence resulted in decreased maximal tangential pedal force in accordance with existing knowledge. Initial cycling at 50 and 90 rpm caused freely chosen cadence to be about 5% lower and higher, respectively, than the freely chosen cadence (72.4 ± 2.4 rpm) at the end of the reference bout. These differences in cadence were not accompanied by statistically significant differences in heart rate. CONCLUSION: The freely chosen cadence depended on the preset cadence applied at the beginning of the bout. This was denoted a phenomenon of motor behavioural history dependence.

A field study investigating sensory manifestations in recreational female cyclists using a novel female-specific cycling pad.

This randomised controlled field study aimed to design a female-specific cycling pad with reduced padding in the crotch area (half-pad) and test its effects on self-reported sensory manifestations in comparison with full-padded cycling bib shorts. Recreational female road cyclists (n = 183) participated (divided into two groups). Self-reported sensory manifestations were collected six times over 12 weeks. Sitting discomfort, wetness perception, thermal, texture sensation, and wear discomfort decreased over time for the crotch and sitting-bones areas in both groups. Irritation and tenderness in the crotch area also decreased over time in both groups. Irritation and tenderness in the sitting-bones area were only higher at week two in the half-pad compared with the full-pad group. Cycling with the half-padded shorts compared with the full-padded ones had no negative effects on sensory manifestations beside the observed transient change at week two. This suggests that foam thickness in the crotch area can be reduced in female-specific cycling pads. Practitioner's Summary: Road cycling might result in discomfort and non-traumatic injuries in the female genital area. This field study compares two different cycling pads; a half-pad and a full-pad, over a 12-week period among female recreational road cyclists. Reducing the foam thickness in the crotch area of the pad does not change sensory manifestations, i.e. discomfort, wetness perception, texture-, and thermal-sensation as well as wear discomfort. Abbreviations: CS-Q: online Cycling bib Shorts Questionnaire; VADER: Valence Aware Dictionary and sEntiment Reasoner.

Effects of 5 Weeks of Bench Press Training on Muscle Synergies: A Randomized Controlled Study.

Kristiansen, M, Samani, A, Madeleine, P, and Hansen, EA. Effects of 5 weeks of bench press training on muscle synergies: A randomized controlled study. J Strength Cond Res 30(7): 1948-1959, 2016-The ability to perform forceful muscle contractions has important implications in sports performance and in activities of daily living. However, there is a lack of knowledge on adaptations in intermuscular coordination after strength training. The purpose of this study was therefore to assess muscle synergies before and after 5 weeks of bench press training. Thirty untrained male subjects were randomly allocated to a training group (TRA) or a control group (CON). After the pretest, TRA completed 5 weeks of bench press training, before completing a posttest, whereas subjects in CON continued their normal life. During test sessions, surface electromyography (EMG) was recorded from 13 different muscles. Muscle synergies were extracted from EMG data using nonnegative matrix factorization. To evaluate differences between pretest and posttest, we performed a cross-correlation analysis and a cross-validation analysis, in which the synergy components extracted in the pretest session were recomputed, using the fixed synergy components from the posttest session. Two muscle synergies accounted for 90% of the total variance and reflected the concentric and eccentric phase, respectively. TRA significantly increased 3 repetition maximum in bench press with 19.0% (25th; 75th percentile, 10.3%; 21.7%) (p < 0.001), whereas no change occurred in CON. No significant differences were observed in synergy components between groups. However, decreases in correlation values for intragroup comparisons in TRA may suggest that the synergy components changed, whereas this was not the case in CON. Strength and conditioning professionals may consider monitoring changes in muscle synergies in training and rehabilitation programs as a way to benchmark changes in intermuscular coordination.

Between-day reliability of the trapezius muscle H-reflex and M-wave.

INTRODUCTION: The aim of this study was to investigate the between-day reliability of the trapezius muscle H-reflex and M-wave. METHODS: Sixteen healthy subjects were studied on 2 consecutive days. Trapezius muscle H-reflexes were evoked by electrical stimulation of the C3/4 cervical nerves; M-waves were evoked by electrical stimulation of the accessory nerve. Relative reliability was estimated by intraclass correlation coefficients (ICC2,1 ). Absolute reliability was estimated by computing the standard error of measurement (SEM) and the smallest real difference (SRD). Bland-Altman plots were constructed to detect any systematic bias. RESULTS: Variables showed substantial to excellent relative reliability (ICC = 0.70-0.99). The relative SEM ranged from 1.4% to 34.8%; relative SRD ranged from 3.8% to 96.5%. No systematic bias was present in the data. CONCLUSIONS: The amplitude and latency of the trapezius muscle H-reflex and M-wave in healthy young subjects can be measured reliably across days.

Pressure pain mapping of the wrist extensors after repeated eccentric exercise at high intensity.

The purpose of this study was to investigate adaptation mechanisms after 2 test rounds consisting of eccentric exercise using pressure pain imaging of the wrist extensors. Pressure pain thresholds (PPTs) were assessed over 12 points forming a 3 × 4 matrix over the dominant elbow in 12 participants. From the PPT assessments, pressure pain maps were computed. Delayed onset muscle soreness was induced in an initial test round of high-intensity eccentric exercise. The second test round performed 7 days later aimed at resulting in adaptation. The PPTs were assessed before, immediately after, and 24 hours after the 2 test rounds of eccentric exercise. For the first test round, the mean PPT was significantly lower 24 hours after exercise compared with before exercise (389.5 ± 64.1 vs. 500.5 ± 66.4 kPa, respectively; p = 0.02). For the second test round, the PPT was similar before and 24 hours after (447.7 ± 51.3 vs. 458.0 ± 73.1 kPa, respectively; p = 1.0). This study demonstrated adaptive effects of the wrist extensors monitored by pain imaging technique in healthy untrained humans. A lack of hyperalgesia, i.e., no decrease in PPT underlined adaptation after the second test round of eccentric exercise performed 7 days after the initial test round. The present findings showed for the first time that repeated eccentric exercise performed twice over 2 weeks protects the wrist extensor muscles from developing exacerbated pressure pain sensitivity. Thus, the addition of eccentric components to training regimens should be considered to induce protective adaptation.

Strength training affects tendon cross-sectional area and freely chosen cadence differently in noncyclists and well-trained cyclists.

The effects of strength training on freely chosen cadence and physiological responses in cyclists and recreationally active individuals were investigated. Well-trained cyclists were assigned to either usual endurance training combined with strength training (C-ES; n = 11) or usual endurance training only (C-E; n = 9). Recreationally active individuals (R-S; n = 7) performed the same strength training as C-ES did (4 lower body exercises, 3 × 4-10 repetition maximum [RM], twice a week for 12 weeks). The R-S and C-ES increased 1RM to a similar extent after 4 and 12 weeks (p < 0.01), whereas 1RM remained unchanged in C-E. Only R-S increased patellar tendon cross-sectional area (CSA; 7 ± 1%, p < 0.001). After 4 weeks, R-S reduced freely chosen cadence, oxygen consumption, heart rate, rating of perceived exertion, and blood lactate concentration during cycling at 125 W. These responses remained reduced throughout the intervention period (p < 0.05). No significant changes were observed in these physiological variables in C-ES and C-E. In conclusion, freely chosen cadence during submaximal cycling was reduced in recreationally active individuals after a period of strength training but was not reduced in well-trained cyclists. The reduced freely chosen cadence may be associated with the observed increase in patellar tendon CSA through a morphological-sensory-motor interaction. A practical application is that heavy strength training can reduce freely chosen cadence during submaximal cycling and thereby improve cycling economy in recreationally active individuals, whereas other mechanisms should account for improved performance after strength training in well-trained cyclists.

Maximal accelerations for twelve weeks elicit improvement in a single out of a collection of cycling performance indicators in trained cyclists.

Introduction: Cycling is a time-consuming sport. Cyclists, as many other athletes, therefore, focus on training effectively. The hypothesis was tested that twelve weeks of supplementary maximal acceleration training caused more favourable changes in cycling performance indicators as compared to changes measured in comparable control cyclists. Methods: Trained cyclists (n = 24) participated. A control group and a group performing maximal acceleration training, as a supplement to their usual training, were formed. The maximal acceleration training consisted of series of ten repetitions of outdoor brief maximal accelerations, which were initiated from low speed and performed in a large gear ratio. The cyclists in the control group performed their usual training. Performance indicators, in form of peak power output in a 7-s maximal isokinetic sprint test, maximal aerobic power output in a graded test, and submaximal power output at a predetermined blood lactate concentration of 2.5 mmol L-1 in a graded test were measured before and after the intervention. Results: Peak power output in the sprint test was increased (4.1% from before to after the intervention) to a larger extent (p = 0.045) in the cyclists who had performed the maximal acceleration training than in the control cyclists (-2.8%). Changes in maximal aerobic power output and in submaximal power output at a blood lactate concentration of 2.5 mmol L-1 were not significantly different between the groups (p > 0.351). Discussion: The results indicated that the applied supplementary maximal acceleration training caused modest favourable changes of performance indicators, as compared to the changes measured in a group of comparable control cyclists.

Freely Chosen Cadence is Increased during Repeated Bouts of Submaximal Ergometer Pedalling.

It was investigated whether the phenomenon of repeated bout rate enhancement occurs during submaximal ergometer cycling. Repeated bout rate enhancement is defined as an increase of the freely, or spontaneously, chosen cadence during repeated bouts of pedalling and has previously been reported for finger tapping. This is relevant to study since cadence can affect biomechanical and physiological responses. Recreationally active individuals (n=27) performed five consecutive 5-min bouts of cycling at 100 W using freely chosen cadence. All bouts were separated by 10-min rest. Cadence, pedal force profile characteristics, heart rate, tympanic temperature, and rate of perceived exertion were determined during cycling. The primary result was that cadence at the end of 5. bout was statistically significantly higher than at the end of all other bouts. Overall, the cadence at the end of 5. bout was 15.6%±20.4% higher than at the end of 1. bout. The altered rhythmic motor behaviour was accompanied by a statistically significant effect of bout on the pedal force profile. Also, there was a statistically significant effect of bout on heart rate, which amounted to 125±17 and 131±26 beats/min at the end of 1. and 5. bout, respectively. Perhaps the observed increase of cadence occurred as a nonconscious rhythmogenesis process in form of a net excitation of relevant parts of the nervous system. In conclusion, repeated bout rate enhancement during submaximal ergometer cycling occurred. The freely chosen cadence showed an increase of on average about 15%, or 10 rpm, as accumulated values across five bouts of cycling.

The puzzle of the walk-to-run transition in humans.

BACKGROUND: The walk-to-run transition, which occurs during gradually increasing locomotion speed, has been addressed in research at least eight decades back. RESEARCH QUESTION: Why does the walk-to-run transition occur? In the present review, we focus on the reason for the transition, more than on the consequences of it. The latter has historically constituted a primary focus. METHODS: In the present review, we scrutinize related literature. RESULTS: We present a unifying conceptual framework of the dynamics of human locomotion. The framework unifies observations of the human walk-to-run transition for providing a common understanding. Further, the framework includes a schematic representation of the dynamic interaction between entities of subsystems of the human body during locomotion and the physical environment. We propose that the moving human body can behave as a dynamic non-linear complex system, which basically functions in a self-organized fashion during locomotion. Further, that the stride rate plays a particular key role for the transition. Finally, we propose that the coincidence between attractor stability and minimum energy turnover during locomotion is a consequence of the evolution of the phenotype of the adult human body and the dynamics of the acute process of self-organization during locomotion. SIGNIFICANCE: The novel insight from the present work contributes to the academic understanding of human locomotion, including in particular the central behavioural phenomenon of walk-to-run transition. Furthermore, the understanding is relevant for the ongoing work within for example locomotion rehabilitation and development of assistive devices. Regarding the latter, examples could be devices within neurorobotics and exoskeletons where the basic understanding of human locomotion increases the possibility of a successful combination of human and technology.

Contralateral Transfer of the Phenomenon of Repeated Bout Rate Enhancement in Unilateral Index Finger Tapping.

These hypotheses were tested: (1) Freely chosen frequency in unilateral index finger tapping is correlated between the two index fingers, and (2) A 3-min bout of unilateral index finger tapping followed by 10 min rest results in an increase of the freely chosen tapping frequency performed by the contralateral index finger in a second bout. Thirty-two adults participated. Freely chosen tapping frequencies from first bouts were 167.2 ± 79.0 and 161.5 ± 69.4 taps/min for the dominant and non-dominant hand, respectively (p=.434). These variables correlated (R=.86, p<.001). When bout one and two were performed with the dominant and non-dominant hand, respectively, the frequency increased by 8.1%±17.2% in bout two (p=.011). In opposite order, the frequency increased by 14.1%±17.5% (p<.001), which was not different from the ∼8% (p=.157).

Energy expenditure and comfort during Nordic walking with different pole lengths.

Energy expenditure and comfort for Nordic walking with self-selected and 7.5-cm shorter poles and ordinary walking were measured during uphill (12 degrees ), downhill (12 degrees ), and horizontally. Twelve (11 women and 1 man) Nordic walking practitioners participated (mean +/- SEM: 171.5 +/- 1.5 cm, 67.0 +/- 2.7 kg, 50.6 +/- 2.4 years, and maximal oxygen uptake of 43.4 +/- 2.8 mL x kg(-1) x min(-1)). Energy expenditure was calculated from oxygen uptake and comfort was self-rated. Differences in physiological responses between the 3 locomotion types at each slope were first analyzed by a 1-way analysis of variance. In case of significance, Student's paired samples 2-tailed t-test was applied twice to test for differences between the 2 pole lengths and between Nordic walking (with self-selected pole length) and ordinary walking. The corresponding differences in comfort were evaluated by a Wilcoxon matched pairs test. The relative exercise intensity during Nordic walking with self-selected pole length ranged between approximately 44 and 87% of the maximal oxygen uptake across the different slopes. For comparison, it ranged between approximately 29 and 80% during ordinary walking. Uphill Nordic walking with short poles compared with poles of self-selected length caused 3% greater energy expenditure. Notwithstanding, comfort was similar. Horizontally and downhill energy expenditure and comfort were similar between pole lengths. Compared with ordinary walking, Nordic walking required as much as 67% greater energy expenditure. Comfort was similar for ordinary and Nordic walking for each slope. In conclusion, shorter poles caused greater energy expenditure during uphill Nordic walking, whereas comfort was similar to poles of self-selected length. The substantially enhanced energy expenditure of Nordic walking compared with previous studies reflects the vigorous technique used here.

A randomized controlled intervention trial to relieve and prevent neck/shoulder pain.

PURPOSE: The objective of this study is to investigate the effect of three different workplace interventions on long-term compliance, muscle strength gains, and neck/shoulder pain in office workers. METHODS: A 1-yr randomized controlled intervention trial was done with three groups: specific resistance training (SRT, n = 180), all-round physical exercise (APE, n = 187), and reference intervention (REF, n = 182) with general health counseling. Physical tests were performed and questionnaires answered at pre-, mid-, and postintervention. The main outcome measures were compliance, changes in maximal muscle strength, and changes in intensity of neck/shoulder pain (scale 0-9) in those with and without pain at baseline. RESULTS: Regular participation was achieved by 54%, 31%, and 16% of those of the participants who answered the questionnaire in SRT (78%), APE (81%), and REF (80%), respectively, during the first half of the intervention period, and decreased to 35%, 28% and 9%, respectively, during the second half. Shoulder elevation strength increased 9-11% in SRT and APE (P < 0.0001). Participants with neck pain at baseline decreased the intensity of neck pain through SRT, from 5.0 +/- 0.2 to 3.4 +/- 0.2 (P < 0.0001), and through APE, from 5.0 +/- 0.2 to 3.6 +/- 0.2 (P < 0.001), whereas REF caused no change. For participants without shoulder pain at baseline, there was a significantly greater increase in pain over the 1-yr period in REF compared with SRT and APE (P < 0.01). CONCLUSION: Compliance was highest in SRT but generally decreased over time. SRT and APE caused increased shoulder elevation strength, were more effective than REF to decrease neck pain among those with symptoms at baseline, and prevent development of shoulder pain in those without symptoms at baseline.

One-year randomized controlled trial with different physical-activity programs to reduce musculoskeletal symptoms in the neck and shoulders among office workers.

OBJECTIVES: This study evaluates the effect of two different worksite physical-activity interventions on neck-shoulder symptoms, together with perceived work ability and sick leave among office workers. METHODS: An examiner-blinded randomized controlled trial was conducted with 549 office workers allocated to one of three intervention groups: one with specific resistance training (SRT) of the neck-shoulder region (N=180), one with all-round physical exercise (APE) (N=187), and one which acted as a reference group, which was informed about general health-promoting activities but did not include a physical activity program (N=182). Questionnaires were filled out at baseline and after 1 year of training. RESULTS: The duration and intensity of neck and shoulder symptoms was lower after the specified worksite physical-activity interventions than in the reference group. On an intervention group level, SRT was not more effective than APE in reducing the duration and intensity of neck and shoulder symptoms. However, those asymptomatic at baseline had a significant lower prevalence of neck-shoulder symptoms at follow-up when allocated to the SRT group than placed in the APE group or reference group. At baseline the work ability index (WAI) was close to 90% of the maximum score, and the mean sick leave was 5 days per year, both being unaffected by the interventions. CONCLUSIONS: Different physical-activity interventions were successful in reducing neck-shoulder symptoms, and SRT was superior to APE in the primary prevention of such symptoms. The initially relatively high WAI was the most probable reason for no further increase in WAI. Likewise the mean sick leave the year before the intervention was very low, and it was probably not possible to reduce it further.

Peak Power Output in Loaded Jump Squat Exercise is Affected by Set Structure.

A priority in strength and power exercise might be to train with as high quality as possible for the shortest possible duration. In this context, peak power output could reflect quality. Designing an exercise session as a cluster set structure, as compared to a traditional set structure, may be a way to obtain higher peak power output in the session. But it is unknown whether that is obtainable for non-elite individuals performing loaded jump squat exercise. The aim of the present study was therefore to test the hypothesis that peak power output would be highest in a jump squat exercise session, which was structured with cluster sets, as compared to traditional sets. Ten individuals (2 women, 8 men; 26.5 ± 4.8 years, 1.81 ± 0.08 m, 90.9 ± 13.2 kg) performed two loaded jump squat exercise sessions structured with cluster sets and traditional sets, respectively. The sessions were performed on two separate days, in counterbalanced order. The position of the barbell was used to calculate derived values including peak power output. Values calculated as averages across the entire exercise sessions showed peak power output to be 178 ± 181 W, corresponding to 4.1% ± 4.9%, higher in the session with cluster set structure, as compared to the session with traditional set structure (p = 0.005). It was concluded that for non-elite individuals, peak power output was approximately 4% higher in a loaded jump squat exercise session structured with cluster sets as compared to an exercise session structured with traditional sets.

Repeated Bout Rate Enhancement Is Elicited by Various Forms of Finger Tapping.

Voluntary rhythmic movements, such as, for example, locomotion and other cyclic tasks, are fundamental during everyday life. Patients with impaired neural or motor function often take part in rehabilitation programs, which include rhythmic movements. Therefore, it is imperative to have the best possible understanding of control and behaviour of human voluntary rhythmic movements. A behavioural phenomenon termed repeated bout rate enhancement has been established as an increase of the freely chosen index finger tapping frequency during the second of two consecutive tapping bouts. The present study investigated whether the phenomenon would be elicited when the first bout consisted of imposed passive finger tapping or air tapping. These two forms of tapping were applied since they can be performed without descending drive (passive tapping) and without afferent feedback related to impact (air tapping) - as compared to tapping on a surface. Healthy individuals (n = 33) performed 3-min tapping bouts separated by 10 min rest. Surface electromyographic, kinetic, and kinematic data were recorded. Supportive experiments were made to measure, for example, the cortical sensory evoked potential (SEP) response during the three different forms of tapping. Results showed that tapping frequencies in the second of two consecutive bouts increased by 12.9 ± 14.8% (p < 0.001), 9.9 ± 6.0% (p = 0.001), and 16.8 ± 13.6% (p = 0.005) when the first bout had consisted of tapping, passive tapping, and air tapping, respectively. Rate enhancement occurred without increase in muscle activation. Besides, the rate enhancements occurred despite that tapping, as compared with passive tapping and air tapping, resulted in different cortical SEP responses. Based on the present findings, it can be suggested that sensory feedback in an initial bout increases the excitability of the spinal central pattern generators involved in finger tapping. This can eventually explain the phenomenon of repeated bout rate enhancement seen after a consecutive bout of finger tapping.

The effect of saddle nose width and cutout on saddle pressure distribution and perceived discomfort in women during ergometer cycling.

The objectives were 1) to design and produce two novel unpadded bicycle saddles with a wide/medium width and partial nose cutout; 2) to investigate the responses on pressure distribution and perceived discomfort in female cyclists. For comparison, a standard saddle was also tested. Nineteen female cyclists pedaled on an ergometer cycle for 20 min with each saddle in a counterbalanced order. A pressure mat measured saddle interface pressure. Discomfort ratings were collected using a visual analogue scale. Total mean saddle pressure remained similar across saddles. The wide saddle increased anterior and decreased posterior mean saddle pressure as compared with the standard (p < .002) and the medium saddle (p < .001). Significantly increased ischial tuberosity discomfort was found for the novel saddles (p < .001), while crotch discomfort was not significantly different between saddles. The medium width saddle appeared to be the best compromise since increased crotch discomfort was avoided and saddle pressures were redistributed. Such design may be suggested as an alternative to traditional saddles for women reporting discomfort in the perineal region.

Effects of Cycling Training at Imposed Low Cadences: A Systematic Review.

The present article reviews effects of training at low imposed cadences in cycling. The authors performed a systematic literature search of MEDLINE and SPORTDiscus up to April 2016 to identify potentially relevant articles. Based on the titles and abstracts of the identified articles, a subset of articles was selected for evaluation. These articles constituted original-research articles on adaptation to training at different imposed cadences in cycling. Seven articles were selected for evaluation. With regard to the terminology in the present article, low cadences are those below the freely chosen cadence. The rate of 80 rpm can, eg, be considered a low cadence if effort is maximal. On the other hand, the cadence has to be lower than 80 rpm (eg, 40-70 rpm) to be considered low if cycling is performed at low power output. The reason is that the choice of cadence depends on power output. In conclusion, there is presently no strong evidence for a benefit of training at low cadences. It can tentatively be recommended to consider including training bouts of cycling at low cadence at moderate to maximal intensity. The reason for the restrained recommendation is that some of the selected studies indicate no clear performance-enhancing effect of training at low cadence or even indicate a superior effect from training at freely chosen cadence. Furthermore, the selected studies are considerably dissimilar with respect to, eg, participant characteristics and to the applied training regimens.

Effect of seat positions on discomfort, muscle activation, pressure distribution and pedal force during cycling.

The aim of this study was to measure and analyse discomfort and biomechanics of cycling, i.e., muscle activation, centre of pressure of seat pressure profiles and pedal forces as a function of seat position. Twenty-one recreationally active individuals cycled for 10min at 100W on an ergometer cycle using five different seat positions. The neutral position was considered as basic seat position and was compared with upward, downward, forward and backward seat positions. The initial bout was repeated at the end of the recording session. Discomfort increased for upward and backward condition compared with neutral (P<0.05). Normalized surface electromyography from gastrocnemius decreased in the downward and forward position but increased in the upward and backward position. The minimum force became less negative for forward position compared with neutral seat position (P<0.05). The degree of variability of centre of pressure increased in the upward and backward position and the entropy of the centre of pressure of sitting posture for backward position decreased compared with neutral seat position (P<0.05). The present study revealed that consecutive changes of seat position over time lead to increase in discomfort as well as alterations of the biomechanics of cycling.