Neuromuscular and physiological variables evolve independently when running immediately after cycling

Use of planar covariation in lower limb kinematics to characterize adaptations of running after cycling in elite triathletes

Purpose

To characterize alterations of lower limb intersegmental coordination during the acute phase of running after cycling among highly trained triathletes using an analysis of planar covariation.

Methods

Nine highly trained triathletes completed a control run (CR) and a run after transitioning from cycling exercise (transition run, or TR condition) on a motorized treadmill at a self-selected pace. Sagittal plane kinematics were recorded using a 3D Vicon motion capture system. Intersegmental coordination of the thigh, shank and foot segments of the right lower limb and run loop planarity were calculated during running before cycling and at four different times after the end of cycling.

Results

PCA showed a significant within-subject phase shift of the run loop planarity (F = 6.66, P = 0.01). Post hoc analysis showed significance median differences increase for u _3t parameter between CR_SS vs. TR₃₀ (P = 0.01), TR_t1/2 (P = 0.01) and TR_MRT (P = 0.01). No difference for u _3t parameter existed between CR_SS vs. TR_SS.

Conclusion

Prior variable-cadence, moderate intensity cycling has a significant effect on run loop planarity and therefore intersegmental coordination during the acute transition phase among highly trained triathletes. However, alterations to lower limb coordination are corrected by the 3rd minute after the beginning of the post cycle run. We suggest that planar covariation can be used as a more sensitive measure of cycling-induced variations in running to characterize adaptation in elite and importantly, developing athletes.

Biomechanical and physiological implications to running after cycling and strategies to improve cycling to running transition: A systematic review

OBJECTIVES

This systematic review summarises biomechanical, physiological and performance factors affecting running after cycling and explores potential effective strategies to improve performance during running after cycling.

DESIGN

Systematic review.

METHODS

The literature search included all documents available until 14th December 2021 from Medline, CINAHL, SportDiscus, and Scopus. Studies were screened against the Appraisal tool for Cross-sectional Studies to assess methodological quality and risk of bias. After screening the initial 7495 articles identified, fulltext screening was performed on 65 studies, with 39 of these included in the systematic review.

RESULTS

The majority of studies observed detrimental effects, in terms of performance, when running after cycling compared to a control run. Unclear implications were identified from a biomechanical and physiological perspective with studies presenting conflicting evidence due to varied experimental designs. Changes in cycling intensity and cadence have been tested but conflicting evidence was observed in terms of biomechanical, physiological and performance outcomes.

CONCLUSIONS

Because methods to simulate cycle to run transition varied between studies, findings were conflicting as to whether running after cycling differed compared to a form of control run. Although most studies presented were rated high to very high quality, it is not possible to state that prior cycling does affect subsequent running, from a physiological point of view, with unclear responses in terms of biomechanical outcomes. In terms of strategies to improve running after cycling, it is unclear if manipulating pedalling cadence or intensity affects subsequent running performance.

Effects of Training on Cardiorespiratory Fitness in Triathletes: A Systematic Review and Meta-Analysis

Triathlon is an aerobic sport, which is commonly measured by maximal aerobic consumption (VO₂max). Objective: to analyze the changes produced in cardiorespiratory and physiological measurements during practice, which determine triathletes’ performance level. A systematic review and a meta-analysis based on PRISMA protocol and registered in PROSPERO (CRD42020189076) was conducted. The research was performed using PubMed, SPORTDiscus, Embase, Dialnet, Web of Science (WOS) and MEDLINE databases during February and March 2020. Studies that measured cardiorespiratory variables in triathletes published in the last 10 years were included. Results: 713 articles were identified, with 25 studies selected for the systematic review and five articles for the meta-analysis. These articles concluded that the main cardiorespiratory variables that determine triathletes’ performance were modified depending on the triathlon segment performed and the athletes’ sex and age. The meta-analysis showed no conclusive results related to the effects of changes in VO₂max in triathletes’ performance [SMD = −0.21; 95%CI: (−0.84 to 0.43)]. Conclusions: cardiorespiratory fitness, in terms of VO₂max and ventilatory thresholds, is the strongest predictor of performance in triathlon. This response may be affected depending on the triathlon segment performed and the athlete’s age or sex, leading to both physiological and biomechanical alterations that affect competition performance.

Comparison of Joint Kinematics in Transition Running and Isolated Running in Elite Triathletes in Overground Conditions

Triathletes often experience incoordination at the start of a transition run (TR); this is possibly reflected by altered joint kinematics. In this study, the first 20 steps of a run after a warm-up run (WR) and TR (following a 90 min cycling session) of 16 elite, male, long-distance triathletes (31.3 ± 5.4 years old) were compared. Measurements were executed on the competition course of the Ironman Frankfurt in Germany. Pacing and slipstream were provided by a cyclist in front of the runner. Kinematic data of the trunk and leg joints, step length, and step rate were obtained using the MVN Link inertial motion capture system by Xsens. Statistical parametric mapping was used to compare the active leg (AL) and passive leg (PL) phases of the WR and TR. In the TR, more spinal extension (~0.5–1°; p = 0.001) and rotation (~0.2–0.5°; p = 0.001–0.004), increases in hip flexion (~3°; ~65% AL−~55% PL; p = 0.001–0.004), internal hip rotation (~2.5°; AL + ~0–30% PL; p = 0.001–0.024), more knee adduction (~1°; ~80–95% AL; p = 0.001), and complex altered knee flexion patterns (~2–4°; AL + PL; p = 0.001–0.01) occurred. Complex kinematic differences between a WR and a TR were detected. This contributes to a better understanding of the incoordination in transition running.

Stretch-Shortening Cycle Function of Lower Limbs After Cycling in Triathletes

Takahashi, K, Shirai, Y, and Nabekura, Y. Stretch-shortening cycle function of lower limbs after cycling in triathletes. J Strength Cond Res XX(X): 000-000, 2020-Impaired cardiorespiratory response and changes in biomechanical variables occur when running after cycling relative to isolated running. Nevertheless, little is known about the causes of these changes or the training to prevent them. This study aimed (a) to determine whether stretch-shortening cycle (SSC) function decreases after cycling exercise and (b) to determine whether the decreases in SSC function are related to brick training. Eleven male university triathletes performed hopping tests to measure SSC function before and after cycling (30 minutes of cycling at 110% ventilatory threshold). Stretch-shortening cycle function was calculated as the ratio of the jump height to the time spent in contact with the ground (reactive strength index [RSI]). Brick training was evaluated by the total experience of brick training. The RSI significantly decreased after the cycling exercise (-10.7%; p < 0.01), but changes in RSI after cycling did not significantly correlate with the total experience of brick training, despite a large effect size (p < 0.10; r = 0.62). These results suggest that SSC function decreases after cycling and that brick training is potentially useful for inhibiting decreases in SSC function after cycling.

Effects of Cycling on Subsequent Running Performance, Stride Length, and Muscle Oxygen Saturation in Triathletes

Running performance is a determinant factor for victory in Sprint and Olympic distance triathlon. Previous cycling may impair running performance in triathlons, so brick training becomes an important part of training. Wearable technology that is used by triathletes can offer several metrics for optimising training in real-time. The aim of this study was to analyse the effect of previous cycling on subsequent running performance in a field test, while using kinematics metrics and SmO₂ provided by wearable devices that are potentially used by triathletes. Ten trained triathletes participated in a randomised crossover study, performing two trial sessions that were separated by seven days: the isolated run trial (IRT) and the bike-run trial (BRT). Running kinematics, physiological outcomes, and perceptual parameters were assessed before and after each running test. The running distance was significantly lower in the BRT when compared to the IRT, with a decrease in stride length of 0.1 m (p = 0.00) and higher %SmO₂ (p = 0.00) in spite of the maximal intensity of exercise. No effects were reported in vertical oscillation, ground contact time, running cadence, and average heart rate. These findings may only be relevant to 'moderate level' triathletes, but not to 'elite' ones. Triathletes might monitor their %SmO₂ and stride length during brick training and then compare it with isolated running to evaluate performance changes. Using wearable technology (near-infrared spectroscopy, accelerometry) for specific brick training may be a good option for triathletes.

The Rise of Elite Short-Course Triathlon Re-Emphasises the Necessity to Transition Efficiently from Cycling to Running

Transitioning efficiently between cycling and running is considered an indication of overall performance, and as a result the cycle–run (C–R) transition is one of the most researched areas of triathlon. Previous studies have thoroughly investigated the impact of prior cycling on running performance. However, with the increasing number of short-course events and the inclusion of the mixed relay at the 2020 Tokyo Olympics, efficiently transitioning from cycle–run has been re-emphasised and with it, any potential limitations to running performance among elite triathletes. This short communication provides coaches and sports scientists a review of the literature detailing the negative effects of prior variable-cycling on running performance experienced among elite, short-course and Olympic distance triathletes; as well as discussing practical methods to minimise any negative impact of cycling on running performance. The current literature suggests that variable-cycling negatively effects running ability in at least some elite triathletes and that improving swimming performance, drafting during cycling and C–R training at race intensity could improve an athlete’s triathlon running performance. It is recommended that future research clearly define the performance level, competitive format of the experimental population and use protocols that are specific to the experimental population in order to improve the training and practical application of the research findings.

Triathlon transition study: quantifying differences in running movement pattern and precision after bike-run transition

Various publications discuss the discrepancies of running in triathlons and stand-alone runs. However, those methods, such as analysing step-characteristics or ground-contact time, lack the ability to quantitatively discriminate between subtle running differences. The attractor method can be applied to overcome those shortcomings. The purpose was to detect differences in athletes' running patterns (δM) and movement precision (δD) by comparing a 5,000 m run after a prior cycling session (TRun) with an isolated run over the same distance (IRun). Participants completed the conditions on a track and a stationary trainer, allowing the use of their personal bike to simulate an Olympic triathlon. During each run, three-dimensional acceleration data, using sensors attached to the ankles, were collected. Results showed that both conditions lead to elevated attractor parameters (δM and δD) over the initial five minutes before the athletes found their rhythm. This generates a new perspective because independent of running after a bike session or without preload, an athlete needs certain time to adjust to the running movement. Coaches must consider this factor as another tool to fine-tune pacing and performance. Moreover, the attractor method is a novel approach to gain deeper insight into human cyclic motions in athletic contexts.