Reliability of Force-Velocity Tests in Cycling and Cranking Exercises in Men and Women

In Situ Power-Cadence Relationship for 2-, 5-, and 20-Minute Duration: A Proof of Concept in Under-19 Cyclists

BACKGROUND

The force-velocity relationship suggests that maximal power (Pmax) can only be produced in optimal torque (Topt) and cadence (Copt). However, the cadence at which mean maximal power (MMP) is produced has never been studied. This study aimed to determine the individual MMP-cadence relationship from in situ data.

METHOD

We analyzed 1 year of data from 14 under-19 cyclists and calculated the MMP for each cadence between 50 and 120 rpm for 2-, 5-, and 20-minute durations. The MMP-cadence relationship was fit with a second-order polynomial function. The goodness of fit (r2) and odd-day-even-day absolute and relative reliability were evaluated, respectively, for Pmax, Topt, and Copt.

RESULTS

The goodness of fit was very high for every duration studied. Topt and Pmax, but not Copt, were significantly higher for shorter durations. Pmax was significantly correlated only with Topt for the 3 durations (r2 = .63, .71, and .64 for 2, 5, and 20 min, respectively).

DISCUSSION

Evaluation of the MMP-cadence relationship from in situ data is feasible and reliable for 2-, 5-, and 20-minute durations. This profiling approach would enable better detection of the strengths and weaknesses of cyclists and make it possible to design more effective training interventions.

PRACTICAL APPLICATIONS

The analysis makes it possible to identify the torque versus cadence component that individually limits power production. Knowing the Copt for a given duration of maximal effort could help athletes choose the right gear ratio and regulate cadence during a race in order to maximize performance.

Force-Velocity Relationship in Cycling and Arm Cranking: A Comparison of Men and Women

This study was aimed at comparing the force-velocity relationship during cycling and arm cranking in males and females. Thirty-two male and twenty-two female healthy volunteers performed a force-velocity test on a cycle ergometer and a cranking ergometer in a randomly selected order. The theoretical values of the maximum force at zero speed (F0) and the maximum velocity at zero braking force (v0) for the lower and upper limbs were determined, and the maximum anaerobic power (Pmax) was calculated from the individual force-velocity relationship. The Pmax and F0 of the upper limbs related to the lower limbs correspond to 78.2 ± 14.3% and 80.1 ± 17.3% in men and 65.5 ± 12.5% and 74.5 ± 6.5% in women, respectively. The theoretical maximum velocity v0 of the upper limbs to the lower limbs attained 129.1 ± 29.0% in men and 127.4 ± 26.4% in women. The results of the study can serve as reference data for the force-velocity characteristics of the upper and lower limbs of male and female athletes. The results can be used both in training and rehabilitation programs, where the starting point is the objectification of possible strength deficits in various areas of the force-velocity characteristic spectrum of the muscles of the upper and lower limbs.

Smart Electrically Assisted Bicycles as Health Monitoring Systems: A Review

This paper aims to provide a review of the electrically assisted bicycles (also known as e-bikes) used for recovery of the rider's physical and physiological information, monitoring of their health state, and adjusting the "medical" assistance accordingly. E-bikes have proven to be an excellent way to do physical activity while commuting, thus improving the user's health and reducing air pollutant emissions. Such devices can also be seen as the first step to help unhealthy sedentary people to start exercising with reduced strain. Based on this analysis, the need to have e-bikes with artificial intelligence (AI) systems that recover and processe a large amount of data is discussed in depth. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were used to complete the relevant papers' search and selection in this systematic review.

Maximal lactate accumulation rate and post-exercise lactate kinetics in handcycling and cycling

The aim of this study was to assess lactate kinetics, maximal lactate accumulation rate (⩒La_max) and peak power output (PO_max) in a 15-s all-out exercise in handcycling (HC) and cycling (C) in terms of (1) reliability, (2) differences and (3) correlations between HC and C. Eighteen female and male competitive triathletes performed two trials (separated by one week) of a 15-s all-out sprint test in HC and C. Tests were performed in a recumbent racing handcycle and on the participants' own road bike that were attached to an ergometer. Reliability was assessed using intraclass correlation coefficient (ICC). PO_max and ⩒La_max demonstrated high reliability in HC (ICC = 0.972, ICC = 0.828) and C (ICC = 0.937, ICC = 0.872). PO_max (d = -2.54, P < 0.0005) and ⩒La_max (d = -1.62, P < 0.0005) were lower in HC compared to C. PO_max and ⩒La_max correlated in HC (r = 0.729, P = 0.001) and C (r = 0.710, P = 0.001). There was no significant correlation between HC and C in PO_max (r = 0.442, P = 0.066) and ⩒La_max (r = 0.455, P = 0.058). Whereas the exchange velocity of lactate (k₁) was similar in HC and C, the removal velocity (k₂) was significantly higher in HC. ⩒La_max and PO_max during sprint exercise are highly reliable and demonstrate a correlation in both HC and C. However, since ⩒La_max and PO_max are significantly higher in C and not correlated between HC and C, ⩒La_max and PO_max seem to be extremity-specific.

Evaluation of the torque-angular velocity relationship across various joint positions

BACKGROUND

Standard neuromuscular assessment through a single value, such as the maximum voluntary torque, could be limited since it changes substantially with movement velocity and joint position and could not discern among force, velocity or power producing capacities of a specific muscle. Therefore, we aimed to evaluate the torque-angular velocity (T-AV) interchange across various joint positions.

METHODS

Knee extensors were tested in 40 physically active participants at six velocities between 30° and 180°/s. Both, linear and the second-order polynomial regression methods were applied on peak torque (TMAX) and angle specific torque outputs (between 80° to 20° of knee extension).

RESULTS

The obtained results suggest decline of the concentric torque as angular velocity increases (P<0.05). The obtained the T-AV relationship appears to be strong and linear for the most subjects (R2=0.74-0.97) and highly reliable (r>0.80) at least when the positions around the TMAX angle are considered.

CONCLUSIONS

The present study revealed that the T-AV relationship of knee extensors, observed from isokinetic tests conducted within a wide range of angular velocities, could be strong, linear and reliable. The results demonstrate that linear regression method could be feasible approach for evaluating individual muscle mechanical capacities.

Effects of an 8-Week In-Season Elastic Band Training Program on Explosive Muscle Performance, Change of Direction, and Repeated Changes of Direction in the Lower Limbs of Junior Male Handball Players

Aloui, G, Hammami, M, Fathloun, M, Hermassi, S, Gaamouri, N, Shephard, RJ, and Chelly, MS. Effects of an 8-week in-season elastic band training program on explosive muscle performance, change of direction, and repeated changes of direction in the lower limbs of junior male handball players. J Strength Cond Res 33(7): 1804-1815, 2019-The aim of this study was to examine the effects of incorporating 8 weeks of biweekly lower-limb elastic band training (knee and hip extension) into the in-season regimen of junior handball players. Study participants (30 men, aged 18.7 ± 0.8 years, body mass 81.1 ± 15.4 kg, height 1.82 ± 0.06 m, body fat: 15.5 ± 5.2%) were randomly assigned between control and experimental groups. Measures obtained before and after intervention included a cycle ergometer force-velocity test, force platform determinations of squat and countermovement jump characteristics, sprint times (5 and 30 m), repeated change-of-direction (RCOD) and change-of-direction (T-half, COD) tests, 1 repetition maximum (RM) half back squat, and anthropometric estimates of limb muscle volumes. Small to trivial improvements of experimental subjects relative to control subjects included peak power (p < 0.001), 1RM strength measures (p < 0.01), sprint times (p < 0.001 for 5 m; p < 0.05 for 30 m), COD (p < 0.01), and all RCOD parameters (p < 0.05) except the RCOD fatigue index. However, vertical jump parameters and limb volumes remained unchanged relative to controls. It may be concluded that adding biweekly elastic band training to a standard conditioning regimen yields small gains in measures that likely have an important influence on handball performance, particularly the ability to sprint, change direction, and make repeated changes of direction. Accordingly, such simple exercises can usefully be adopted as a component of handball training.

Selective Changes in the Mechanical Capacities of Lower-Body Muscles After Cycle-Ergometer Sprint Training Against Heavy and Light Resistances

PURPOSE

To explore the feasibility of the linear force-velocity (F-V) modeling approach to detect selective changes of F-V parameters (ie, maximum force [F₀], maximum velocity [V₀], F-V slope [a], and maximum power [P₀]) after a sprint-training program.

METHODS

Twenty-seven men were randomly assigned to a heavy-load group (HLG), light-load group (LLG), or control group (CG). The training sessions (6 wk × 2 sessions/wk) comprised performing 8 maximal-effort sprints against either heavy (HLG) or light (LLG) resistances in leg cycle-ergometer exercise. Pre- and posttest consisted of the same task performed against 4 different resistances that enabled the determination of the F-V parameters through the application of the multiple-point method (4 resistances used for the F-V modeling) and the recently proposed 2-point method (only the 2 most distinctive resistances used).

RESULTS

Both the multiple-point and the 2-point methods revealed high reliability (all coefficients of variation <5% and intraclass correlation coefficients >.80) while also being able to detect the group-specific training-related changes. Large increments of F₀, a, and P₀ were observed in HLG compared with LLG and CG (effect size [ES] = 1.29-2.02). Moderate increments of V₀ were observed in LLG compared with HLG and CG (ES = 0.87-1.15).

CONCLUSIONS

Short-term sprint training on a leg cycle ergometer induces specific changes in F-V parameters that can be accurately monitored by applying just 2 distinctive resistances during routine testing.

Influence of ethnicity on vertical jump performances in male physical education students: a pilot study

BACKGROUND

The present study aimed to: 1) test the possibility of ethnic differences in squat jump (SJ), countermovement jump (CMJ) and countermovement jump with arms swing (CMJA); 2) test the possibility of ethnic differences in the effects of countermovement and arms swing; 3) verify whether the relationships between the different vertical jumps (VJ) (SJ, CMJ, CMJA) and maximal power (Pmax), determined from a force-velocity test (F-V), were dependent on the ethnicity as previously found for CMJA.

METHODS

VJ were performed by 84 active men (WAC): 40 WA and 44 C. VJ were measured on a force platform in three conditions: SJ, CMJ and CMJA. For technical reasons, only 39 of these participants (WA2C2) performed F-V test [V=V0(1-F/F0) and maximal power=0.25 V0F0]: 20 WA (WA2) and 19 C (C2).

RESULTS

There were significant ethnic differences (WA>C) in SJ, CMJ, CMJA, CMJA-CMJ, CMJA/CMJ. The effect sizes (Cohen d) of these ethnic differences were large for CMJA (0.93), CMJA-CMJ (1.11) CMJA/CMJ (0.82) and medium for CMJ (0.54) and SJ (0.56). Ethnic effect in the countermovement jump was small (Cohen d=0.04 for CMJ-SJ) and not significant.

CONCLUSIONS

For WA2C2, the slightly higher value of Pmax in WA2 (Cohen d =0.23) probably explained their slightly higher values of SJ, CMJ but not their higher values of CMJA and arms swing effect. In WA2C2, a difference in fast-fiber percentages was not the explanation of the ethnic differences because the optimal pedal rates corresponding to Pmax (0.5 V0) were similar in both groups.

Allometric scaling of power-force-velocity ergometry profiles in men

AIM

To examine the appropriate magnitude of allometric scaling of the force-velocity relationship according to body dimensions and to establish normative data for the power-force-velocity relationship for active men.

SUBJECTS AND METHODS

Ninety-seven participants completed a force-velocity test on a Monark cycle ergometer. Allometric exponents and percentile ranks were established for maximal power (Pmax), maximal force (F0) and maximal velocity (V0).

RESULTS

The mean (± SD) of Pmax, F0 and V0 were 1114.90 ± 160.60 W, 191.97 ± 26.51 N, and 227.87 ± 8.82 rpm, respectively. V0 was not related to any body size descriptors. Allometric exponents for Pmax, and F0 scaled for body mass were b = 0.77 (0.64-0.90) and 0.74 (0.61-0.86), respectively. Correlations between allometrically scaled Pmax and F0 with body mass were r = 0.002 (p = 0.984) and r = 0.008 (p = 0.940), respectively, suggesting that the allometric exponents derived were effective in partialling out the effect of body mass on Pmax and F0 results.

CONCLUSIONS

The allometric exponents and normative values of the current study provide a useful tool for comparing the scores of force-velocity tests between individuals without the confounding effect of body size.

Force-velocity relationship of leg muscles assessed with motorized treadmill tests: Two-velocity method

Linear regression models applied on force (F) and velocity (V) data obtained from loaded multi-joint functional movement tasks have often been used to assess mechanical capacities of the tested muscles. The present study aimed to explore the properties of the F-V relationship of leg muscles exerting the maximum pulling F at a wide range of V on a standard motorized treadmill. Young and physically active male and female subjects (N=13+15) were tested on their maximum pulling F exerted horizontally while walking or running on a treadmill set to 8 different velocities (1.4-3.3m/s). Both the individual (median R=0.935) and averaged across the subjects F-V relationships (R=0.994) proved to be approximately linear and exceptionally strong, while their parameters depicting the leg muscle capacities for producing maximum F, V, and power (P; proportional to the product of F and V) were highly reliable (0.84<ICC<0.97). In addition, the same F-V relationship parameters obtained from only the highest and lowest treadmill V (i.e., the 'two-velocity method') revealed a strong relationship (0.89<R<0.99), and there were no meaningful differences regarding the magnitudes of the same parameters obtained from all 8 V's of the treadmill. We conclude that the F-V relationship of leg muscles tested through a wide range of treadmill V could be strong, linear, and reliable. Moreover, the relatively quick and fatigue-free two-velocity method could provide reliable and ecologically valid indices of F, V, and P producing capacities of leg muscles and, therefore, should be considered for future routine testing.

Relation between Peak Power Output in Sprint Cycling and Maximum Voluntary Isometric Torque Production

From a cycling paradigm, little has been done to understand the relationships between maximal isometric strength of different single joint lower body muscle groups and their relation with, and ability to predict PPO and how they compare to an isometric cycling specific task. The aim of this study was to establish relationships between maximal voluntary torque production from isometric single-joint and cycling specific tasks and assess their ability to predict PPO. Twenty male trained cyclists participated in this study. Peak torque was measured by performing maximum voluntary contractions (MVC) of knee extensors, knee flexors, dorsi flexors and hip extensors whilst instrumented cranks measured isometric peak torque from MVC when participants were in their cycling specific position (ISOCYC). A stepwise regression showed that peak torque of the knee extensors was the only significant predictor of PPO when using SJD and accounted for 47% of the variance. However, when compared to ISOCYC, the only significant predictor of PPO was ISOCYC, which accounted for 77% of the variance. This suggests that peak torque of the knee extensors was the best single-joint predictor of PPO in sprint cycling. Furthermore, a stronger prediction can be made from a task specific isometric task.