The relationship between cadence,pedalling technique and gross efficiency in cycling

Technique and energy saving are two variables often considered as important for performance in cycling and related to each other. Theoretically, excellent pedalling technique should give high gross efficiency (GE). The purpose of the present study was to examine the relationship between pedalling technique and GE. 10 well-trained cyclists were measured for GE, force effectiveness (FE) and dead centre size (DC) at a work rate corresponding to ~75% of VO₂max during level and inclined cycling, seat adjusted forward and backward, at three different cadences around their own freely chosen cadence (FCC) on an ergometer. Within subjects, FE, DC and GE decreased as cadence increased (p < 0.001). A strong relationship between FE and GE was found, which was to great extent explained by FCC. The relationship between cadence and both FE and GE, within and between subjects, was very similar, irrespective of FCC. There was no difference between level and inclined cycling position. The seat adjustments did not affect FE, DC and GE or the relationship between them. Energy expenditure is strongly coupled to cadence, but force effectiveness, as a measure for pedalling technique, is not likely the cause of this relationship. FE, DC and GE are not affected by body orientation or seat adjustments, indicating that these parameters and the relationship between them are robust to coordinative challenges within a range of cadence, body orientation and seat position that is used in regular cycling.     

Cadence and performance in elite cyclists

Many studies have attempted to describe the optimal cadence in cycling. However, the effect on performance has received little attention. The aim of the present study was therefore to examine the effect of cadence on performance during prolonged cycling (~30 min). Fourteen male elite cyclists performed two or five time trials at different cadences [60, 80, 100, 120 rpm or freely chosen cadence (FCC)]. The total work was the same between the time trials, and the subjects were instructed to complete each time trial as fast as possible by adjusting the workload with buttons mounted on the handlebar. Accumulated work and cadence was visualised on a monitor. Oxygen uptake was measured continuously and blood lactate concentration every fifth minute. Compared to 80 rpm, finishing times at 60, 100 and 120 rpm were 3.5, 1.7 and 10.2% slower (P<0.05). Finishing time at FCC (mean 90 rpm) was indistinguishable from 80 and 100 rpm. Gross efficiency at 80 rpm was 2.9, 2.3, 3.4 and 12.3% larger than at 60, FCC, 100 and 120 rpm, respectively (P<0.05). The maximal energy turnover rate was 1.7% higher at 100 than at 80 rpm (P<0.05). This could not, however, compensate for the 3.4% lower efficiency at 100 rpm. This study demonstrated that elite cyclists perform best at their most efficient cadence despite the maximal energy turnover rate being larger at a higher cadence.     

Factors associated with the selection of the freely chosen cadence in non-cyclists

The purpose of this study was to examine both the freely chosen cadence (FCC) and the physical variables associated with cadence selection in non-cyclists. Eighteen participants pedalled at 40, 50, and 60% of their maximal power output (determined by a maximal oxygen uptake test, W _max), whilst cadence (50, 65, 80, 95, 110 rpm, and FCC) was manipulated. Gross efficiency, was used to analyse the most economical cadence whilst central and peripheral ratings of perceived exertion (RPE) were used to measure the most comfortable cadence and the cadence whereby muscle strain was minimised. Peak (T _peak), mean crank torque (T _mean) and the crank torque profile were analysed at 150 and 200 W at cadences of 50, 65, 80, 95, and 110 rpm in order to determine the mechanical load. FCC was found to be approximately 80 rpm at all workloads and was significantly higher than the most economical cadence (50 rpm). At 60% W _max, RPE peripheral was minimised at 80 rpm which coincided with the FCC. Both T _peak and T _mean decreased as cadence increased and, conversely, increased as power output increased. An analysis of the crank torque profile showed that the crank angle at both the top (DP_top) and the bottom (DP_bot) dead point of the crank cycle at 80 rpm occurred later in the cycling revolution when compared to 50 rpm. The findings suggested that the FCC in non-cyclists was more closely related to variables that minimise muscle strain and mechanical load than those associated with minimising metabolic economy.     

Power-cadence relationship in endurance cycling

In maximal sprint cycling, the power–cadence relationship to assess the maximal power output (P _max) and the corresponding optimal cadence (C _opt) has been widely investigated in experimental studies. These studies have generally reported a quadratic power–cadence relationship passing through the origin. The aim of the present study was to evaluate an equivalent method to assess P _max and C _opt for endurance cycling. The two main hypotheses were: (1) in the range of cadences normally used by cyclists, the power–cadence relationship can be well fitted with a quadratic regression constrained to pass through the origin; (2) P _max and C _opt can be well estimated using this quadratic fit. We tested our hypothesis using a theoretical and an experimental approach. The power–cadence relationship simulated with the theoretical model was well fitted with a quadratic regression and the bias of the estimated P _max and C _opt was negligible (1.0 W and 0.6 rpm). In the experimental part, eight cyclists performed an incremental cycling test at 70, 80, 90, 100, and 110 rpm to yield power–cadence relationships at fixed blood lactate concentrations of 3, 3.5, and 4 mmol L⁻¹. The determined power outputs were well fitted with quadratic regressions (R ² = 0.94–0.96, residual standard deviation = 1.7%). The 95% confidence interval for assessing individual P _max and C _opt was ±4.4 W and ±2.9 rpm. These theoretical and experimental results suggest that P _max, C _opt, and the power–cadence relationship around C _opt could be well estimated with the proposed method.     

Influence of cycling cadence on neuromuscular activity of the knee extensors in humans

The aim of the present study was to investigate the influence of pedalling rate and power output in cycling on the neuromuscular activity of the knee extensor muscles. Ten subjects took part in 15 randomised trials, which consisted of three levels of power outputs (60%, 80% and 100% maximal aerobic power) and five cadences (70%, 85%, 100%, 115% and 130% of the freely chosen cadence, FCC). Root mean square (rms) was utilized to quantify electromyographic activity of the vastus lateralis (VL), vastus medialis (VM) and rectus femoris (RF) muscles. The mean (SD) FCC did not change with power output, ranging from 85.0 (11.9) to 88.0 (11.1) rpm. A significant power effect (P<0.01) for the rms of VL, VM and RF muscles was observed. Results showed no significant cadence effect on neuromuscular activity of the VL and VM muscles, while the rms of the RF muscle was significantly greater (P<0.05) at 70% FCC when compared to other cadences. In conclusion, the neuromuscular activity of the knee extensor muscles was not significantly influenced by cadence manipulations. Thus, minimisation of the neuromuscular activity of these muscles would not seem to lead to the choice of a cadence in cycling. Electronic Publication     

The energetically optimal cadence decreases after prolonged cycling exercise

This study investigated the change in the energetically optimal cadence after prolonged cycling. The energetically optimal cadence (EOC) was determined in 14 experienced cyclists by pulmonary gas exchange at six different cadences (100–50 rpm at 10 rpm intervals). The determination of the EOC was repeated after a prolonged cycling exercise of 55 min duration, where cadence was fixed either at high (>95 rpm) or low (<55 rpm) pedalling rates. The EOC decreased after prolonged cycling exercise at a high as well as at a low fixed cadence (P < 0.01). According to the generalized muscle equations of Hill, this indicates that most likely more type I muscle fibres contribute to muscular power output after fatiguing cycling exercise compared to cycling in the beginning of an exercise bout. We suggest that the determination of EOC might be a potential non-invasive method to detect the qualitative changes in activated muscle fibres, which needs further investigation.     

Efficiency in cycling: a review

We focus on the effect of cadence and work rate on energy expenditure and efficiency in cycling, and present arguments to support the contention that gross efficiency can be considered to be the most relevant expression of efficiency. A linear relationship between work rate and energy expenditure appears to be a rather consistent outcome among the various studies considered in this review, irrespective of subject performance level. This relationship is an example of the Fenn effect, described more than 80 years ago for muscle contraction. About 91% of all variance in energy expenditure can be explained by work rate, with only about 10% being explained by cadence. Gross efficiency is strongly dependent on work rate, mainly because of the diminishing effect of the (zero work-rate) base-line energy expenditure with increasing work rate. The finding that elite athletes have a higher gross efficiency than lower-level performers may largely be explained by this phenomenon. However, no firm conclusions can be drawn about the energetically optimal cadence for cycling because of the multiple factors associated with cadence that affect energy expenditure.     

Effect of pedalling rates on physiological response during endurance cycling

This study was undertaken to examine the effect of different pedalling cadences upon various physiological responses during endurance cycling exercise. Eight well-trained triathletes cycled three times for 30 min each at an intensity corresponding to 80% of their maximal aerobic power output. The first test was performed at a freely chosen cadence (FCC); two others at FCC - 20% and FCC + 20%, which corresponded approximately to the range of cadences habitually used by road racing cyclists. The mean (SD) FCC, FCC - 20% and FCC + 20% were equal to 86 (4), 69 (3) and 103 (5) rpm respectively. Heart rate (HR), oxygen uptake (VO2), minute ventilation (VE) and respiratory exchange ratio (R) were analysed during three periods: between the 4th and 5th, 14th and 15th, and 29th and 30th min. A significant effect of time (P < 0.01) was found at the three cadences for HR, VO2. The VE and R were significantly (P < 0.05) greater at FCC + 20% compared to FCC - 20% at the 5th and 15th min but not at the 30th min. Nevertheless, no significant effect of cadence was observed in HR and VO2. These results suggest that, during high intensity exercise such as that encountered during a time-trial race, well-trained triathletes can easily adapt to the changes in cadence allowed by the classical gear ratios used in practice.     

The most economical cadence increases with increasing workload

Several studies have suggested that the most economical cadence in cycling increases with increasing workload. However, none of these studies have been able to demonstrate this relationship with experimental data. The purpose of this study was to test the hypothesis that the most economical cadence in elite cyclists increases with increasing workload and to explore the effect of cadence on performance. Six elite road cyclists performed submaximal and maximal tests at four different cadences (60, 80, 100 and 120 rpm) on separate days. Respiratory data was measured at 0, 50, 125, 200, 275 and 350 W during the submaximal test and at the end of the maximal test. The maximal test was carried out as an incremental test, conducted to reveal differences in maximal oxygen uptake and time to exhaustion (short-term performance) between cadences. The results showed that the lowest oxygen uptake, i.e. the best work economy, shifted from 60 rpm at 0 W to 80 rpm at 350 W (P<0.05). No difference was found in maximal oxygen uptake among cadences (P>0.05), while the best performance was attained at the same cadence that elicited the best work economy (80 rpm) at 350 W (P<0.05). This study demonstrated that the most economical cadence increases with increasing workload in elite cyclists. It was further shown that work economy and performance are related during short efforts (~5 min) over a wide range of cadences.     

Effect of internal power on muscular efficiency during cycling exercise

The purpose of this study was to investigate the muscular efficiency during cycling exercise under certain total power output (P _tot) or external power output (P _ext) experimental conditions that required a large range of pedal rates from 40 to 120 rpm. Muscular efficiency estimated as a ratio of P _tot, which is sum of internal power output (P _int) and P _ext, to rate of energy expenditure above a resting level was investigated in two experiments that featured different conditions on a cycle ergometer, which were carried out at the same levels of P _tot (Exp. 1) and P _ext (Exp. 2). Each experiment consisted of three exercise tests with three levels of pedal rates (40, 80 and 120 rpm) lasting for 2–3 min of unloaded cycling followed by 4–5 min of loaded cycling. during unloaded cycling (∼430 ml min⁻¹ for 40 rpm, ∼640 ml min⁻¹ for 80 rpm, ∼1,600 ml min⁻¹ for 120 rpm) and the P _int (∼3 W for 40 rpm, ∼25 W for 80 rpm, ∼90 W for 120 rpm) in the two experiments were markedly increased with increasing pedal rates. The highest muscular efficiency was found at 80 rpm in the two experiments, whereas a remarkable reduction (19%) in muscular efficiency obtained at 120 rpm could be attributable to greater O₂ cost due to higher levels of P _int accompanying the increased pedal rates. We concluded that muscular efficiency could be affected by the differences in O₂ cost and P _int during cycling under the large range of pedal rates employed in this study.     

Effect of exercise duration on optimal pedaling rate choice in triathletes.

The purpose of this study was to investigate the effect of an exercise duration similar to triathlon's cyclism event (approximately 1 hr), on factors determining the freely chosen cadence. Nine trained triathletes completed a cycling track session conducted at a speed corresponding to 75% of maximal heart rate. This session was composed of five submaximal rides performed at five cadences presented in a random order (65, 80, 95, 110 rpm and freely chosen cadence) realized before and after a 1-hr exercise at the freely chosen cadence. Results show, during the first condition, that triathletes choose spontaneously a cadence (90,1 +/- 10,7 rpm) close to the neuromuscular optimum (89,6 +/- 1,1 rpm) while at the end of exercise, a decrease of the freely chosen cadence (82,8 +/- 8,7 rpm) was observed toward the energetically optimal cadence (78,6 +/- 5,8 rpm). These findings suggest the hypothesis of an adaptation of the movement pattern with the exercise duration in order to minimize the energy cost rather than the neuromuscular cost of cycling.     

Effect of "Pose" cycling on efficiency and pedaling mechanics

The purpose of this study was to determine the effect of “Pose” cycling (a combination of specific bicycle setup and pedaling technique) on metabolic efficiency and pedaling mechanics. Eighteen recreational cyclists were tested for efficiency and pedaling mechanics during steady-state cycling (90% gas-exchange threshold) using two different bicycle setups (preferred and “Pose”) and three different pedaling rates (70, 90 and 110 rpm). Nine of the participants underwent a coaching intervention (4 × 1 h) consisting of drills based on the “Pose” instruction manual. The remaining nine participants did not receive an intervention. All participants were tested before and after the intervention period. Analyses of variance were performed to test the independent effects of the “Pose”-specific bicycle setup and pedaling technique on gross efficiency and pedaling mechanics. The “Pose”-specific bicycle setup resulted in increased gross efficiency at each pedaling rate compared to the participants’ preferred bicycle position (P < 0.05). This increase in efficiency was accompanied by a significant increase in trunk frontal area (P < 0.05). The coaching intervention resulted in decreased gross efficiency at 110 rpm (P < 0.05); at this pedaling rate the intervention resulted in a slight increase in the non-muscular contribution to pedal power in the experimental group and a decrease in the control group. The combination of changed bicycle setup and pedaling technique had no effect on gross efficiency and only small effects on pedaling mechanics. Our findings add to a growing body of literature that short-term interventions in pedaling technique can change pedaling mechanics but do not improve efficiency during steady-state cycling.     

Gear, inertial work and road slopes as determinants of biomechanics in cycling

In cycling the gear determines the distance travelled and the mean applied force at each leg thrust. According to Padilla et al. (J Appl Physiol 89:1522–1527, 2000), an elite cyclist was able to cycle for an hour at 14.6 m·s^–1 developing 510 W at a pedal frequency of 101 rpm. Thus, the opposing force was 34 N (=500/14.6), whereas the mean force, developed by the leg muscles, was 144.1 N. It can be calculated that in the same subject cycling on a 20% slope at the same pedal frequency, the velocity would be reduced by about 5 times, i.e. to 2.9 m·s^–1because of a fivefold increase of the opposing force. In reality, the increase of mean force developed by leg muscles is even larger, because of the fall of the cadence to 60 rpm. In general, during mountain ascents cyclists develop high forces at low cadences that are likely to be more economical; in contrast, on flat ground, they increase the pedalling rates because their aerodynamic posture does not allow high force production. The intermittent pattern of muscular force application generates speed changes that become more evident at great inclines and low cadences. It can be shown that inertial work is appreciable in cycling, increasing with the incline of the road and decreasing with the cadence. However, inertial work does not seem to affect efficiency. Differences in physiologic potential make differences in performance more evident in time trials where the mean incline of the road is not negligible. Cyclists with low body size have an advantageous force versus mass ratio in high mountain ascents.     

Interactions between cadence and power output effects on mechanical efficiency during sub maximal cycling exercises

The purpose of this study was to investigate the interactions between cadence and power output effects on cycling efficiency. Fourteen healthy subjects performed four constant power output-tests (40, 80, 120 and 160 W) in which the cadence varied in five bouts from 40 to 120 rpm. Gross efficiency (GE) was determined over the last ten respiratory cycles of each bout and was calculated as the ratio of mechanical energy to energy expenditure. Results showed that (1) GE-cadence relationships reached a maximum at each power output corresponding to the cadence maximising efficiency (CA_eff) and (2) GE increased with power output whatever the cadence until a maximal theoretical value. Moreover, interactions were found between these two factors: the cadence effect decreased linearly with power output and the power output effect increased exponentially with cadence. Consequently, cycling efficiency decreased more when cadence differed from CA_eff at low than at high power output, and increased more with power output at high cadence than at low cadence. These interactions between cadence and power output effects on GE were mainly due to cadence and power output effects on the energy expenditure shares not contributing to power production.An erratum to this article can be found at     

Strength training reduces freely chosen pedal rate during submaximal cycling

The freely chosen pedal rate is relatively high and energetically inefficient during submaximal cycling, which is a paradox since the rate of energy expenditure is considered important for voluntary motor behavior in other cyclical activities as, e.g., running. For example, it has been suggested that subjects pedal fast to reduce the perception of force. In this study, we investigated the hypothesis that strength training would cause subjects to pedal at a slower rate during low to moderate submaximal cycling. Fourteen healthy subjects performed supervised heavy (2–12 RM) strength training 4 days/week for 12 weeks, including 2 days/week with leg-extensor and knee-flexor exercises. Seven healthy subjects formed the control group. The training group increased strength (one repetition maximum, 1 RM) in both squat [20%(3), mean (SEM)] and leg curl [12%(1)] exercises from the beginning to the end of the study period (p < 0.01). At the same time, freely chosen pedal rate was reduced by 8 (2) and 10 (2) rpm, respectively, during cycling at 37 and 57% of maximal power output (W _max) (p < 0.01). In addition, rate of energy expenditure is 3% (2) lower at 37% of W _max (p < 0.05) and tended to be lower at 57% W _max (p = 0.07) at the end of the study. Values for strength, freely chosen pedal rate, and rate of energy expenditure, were unchanged for the control group from the beginning to the end of the study. In conclusion, strength training caused subjects to choose a ∼9 rpm lower pedal rate during submaximal cycling. This was accompanied by a ∼3% lower rate of energy expenditure.     

Alterations in neuromuscular function and perceptual responses following acute eccentric cycling exercise

Previous investigators have reported velocity-dependent strength loss for single-joint actions following acute eccentric exercise. The extent to which velocity influences recovery of multi-joint function is not well documented. Our main purpose was to compare alterations in maximal cycling power produced across a range of pedaling rates following eccentric exercise. An additional purpose was to determine the extent to which changes in rating of perceived exertion (RPE) associated with submaximal cycling reflect changes in maximal cycling power. Eighteen cyclists performed baseline trials of maximal and submaximal single-leg concentric cycling immediately before and 24 and 48 h after acute submaximal single-leg eccentric (151 ± 32 W, 487 ± 107 s) and concentric (148 ± 21 W, 488 ± 79 s) cycling trials. Maximum cycling power (apex of power–pedaling rate relationship; P _max) was assessed using inertial-load cycling, and powers produced at 65, 110 and 155 rpm were also analyzed. Compared to baseline, P _max was reduced (11–13%) at 24–48 h in the eccentric leg (P < 0.001). Power produced at 65, 110 and 155 rpm was reduced by similar relative magnitudes (11–15%) at 24–48 h in the eccentric leg. RPE increased (15–18%) at 24–48 h in the eccentric leg (P < 0.001). Magnitudes of relative changes in RPE did not differ from those for P _max. There were no alterations in the concentric leg. Our results indicated a global, rather than velocity-specific, reduction in neuromuscular function. Such a global reduction does not support the notion of fiber-type specific damage from eccentric exercise. The similar relative changes in RPE and P _max suggest that increased exertion may reflect the need to recruit additional motor units to produce the same submaximal power.     

Performance following prolonged sub-maximal cycling at optimal versus freely chosen pedal rate

It was tested whether cyclists perform better during all-out cycling following prolonged cycling at the pedal rate resulting in minimum oxygen uptake (VO₂), i.e. the energetically optimal pedal rate (OPR) rather than at the freely chosen pedal rate (FCPR). Nine trained cyclists cycled at 180 W to determine individual OPR and FCPR. Baseline performance was determined by measuring mean power output (W_5min) and peak VO₂ during 5-min all-out cycling at FCPR. Subsequently, on two separate days, the cyclists cycled 2.5 h at 180 W at OPR and FCPR, with each bout followed by a 5-min all-out trial. FCPR was higher (P < 0.05) than OPR at 180 W (95 ± 7 and 73 ± 11 rpm, respectively). During the prolonged cycling, VO₂, heart rate (HR), and rate of perceived exertion (RPE) were 7–9% higher (P < 0.05) at FCPR than at OPR and increased (P < 0.05) 2–21% over time. During all-out cycling following prolonged cycling at OPR and FCPR, W_5min was 8 and 10% lower (P < 0.05) than at baseline, respectively. Peak VO₂ was lower (P < 0.05) than at baseline only after FCPR. The all-out trial power output was reduced following 2.5 h of cycling at 180 W at both OPR and FCPR. However, this aspect of performance was similar between the two pedal rates, despite a higher physiological load (i.e. VO₂, HR, and RPE) at FCPR during prolonged cycling. Still, a reduced peak VO₂ only occurred after cycling at FCPR. Therefore, during prolonged sub-maximal cycling, OPR is at least as advantageous as FCPR for performance optimization in subsequent all-out cycling.     

Effect of end-point cadence on the maximal work-time relationship

This study examined the effect of end-point cadence on the parameters of the work-time relationship determined for cycle ergometry. Eight male subjects completed four maximal tests on an electrically-braked cycle ergometer that regulated a constant power output independent of cadence. The power outputs imposed ranged between an average of 259 W and 403 W, whereas the corresponding durations ranged between 139 s and 1691 s. During each test subjects were required to maintain a cadence of 80–90 rpm. Accumulated time to end-point cadences of 70, 60 and 50 rpm were recorded. The four work-time determinations for each of three end-point cadences were used to determine linear relationships between work and time, yielding both a y-intercept, which represents anaerobic work capacity, and a slope, which is termed critical power (CP), for each end-point cadence. There was a significant increase in the y-intercept as end-point cadence decreased from 70 to 60 rpm (F[1,7]=36.7, p < 0.001) or 70 to 50 rpm (F[1,7]=80.1, p < 0.001), but not from 60 rpm to 50 rpm (F[1,7]=3.28, p > 0.05). In contrast, there was no effect of end-point cadence on CP (F[2,14]=1.89, p < 0.05). These results demonstrate that the end-point cadence selected to terminate tests only affects the y-intercept of the work-time relationship. To control for this effect, the cadence at which each test is terminated should be standardised if determination of anaerobic work capacity, as represented by the y-intercept, is required.     

Effect of isokinetic cycling versus weight training on maximal power output and endurance performance in cycling

The aim of this study was to compare the effects of a weight training program for the leg extensors with isokinetic cycling training (80 rpm) on maximal power output and endurance performance. Both strength training interventions were incorporated twice a week in a similar endurance training program of 12 weeks. Eighteen trained male cyclists (VO_2peak 60 ± 1 ml kg⁻¹ min⁻¹) were grouped into the weight training (WT n = 9) or the isokinetic training group (IT n = 9) matched for training background and sprint power (P _max), assessed from five maximal sprints (5 s) on an isokinetic bicycle ergometer at cadences between 40 and 120 rpm. Crank torque was measured (1 kHz) to determine the torque distribution during pedaling. Endurance performance was evaluated by measuring power, heart rate and lactate during a graded exercise test to exhaustion and a 30-min performance test. All tests were performed on subjects’ individual race bicycle. Knee extension torque was evaluated isometrically at 115° knee angle and dynamically at 200° s⁻¹ using an isokinetic dynamometer. P _max at 40 rpm increased in both the groups (~15%; P < 0.05). At 120 rpm, no improvement of P _max was found in the IT training group, which was possibly related to an observed change in crank torque at high cadences (P < 0.05). Both groups improved their power output in the 30-min performance test (P < 0.05). Isometric knee extension torque increased only in WT (P < 0.05). In conclusion, at low cadences, P _max improved in both training groups. However, in the IT training group, a disturbed pedaling technique compromises an improvement of P _max at high cadences.     

Determinants of maximal cycling power: crank length, pedaling rate and pedal speed

The purpose of this investigation was to determine the effects of cycle crank length on maximum cycling power, optimal pedaling rate, and optimal pedal speed, and to determine the optimal crank length to leg length ratio for maximal power production. Trained cyclists (n=16) performed maximal inertial load cycle ergometry using crank lengths of 120, 145, 170, 195, and 220 mm. Maximum power ranged from a low of 1149 (20) W for the 220-mm cranks to a high of 1194 (21) W for the 145-mm cranks. Power produced with the 145- and 170-mm cranks was significantly (P<0.05) greater than that produced with the 120- and 220-mm cranks. The optimal pedaling rate decreased significantly with increasing crank length, from 136 rpm for the 120-mm cranks to 110 rpm for the 220-mm cranks. Conversely, optimal pedal speed increased significantly with increasing crank length, from 1.71 m/s for the 120-mm cranks to 2.53 m/s for the 220-mm cranks. The crank length to leg length and crank length to tibia length ratios accounted for 20.5% and 21.1% of the variability in maximum power, respectively. The optimal crank length was 20% of leg length or 41% of tibia length. These data suggest that pedal speed (which constrains muscle shortening velocity) and pedaling rate (which affects muscle excitation state) exert distinct effects that influence muscular power during cycling. Even though maximum cycling power was significantly affected by crank length, use of the standard 170-mm length cranks should not substantially compromise maximum power in most adults. Electronic Publication