Bilateral asymmetry of skin temperature is not related to bilateral asymmetry of crank torque during an incremental cycling exercise to exhaustion

Abstract

Although moderate relationships (|r| ∼ 0.5) were reported between skin temperature and performance-related variables (e.g., kinetic), it remains unclear whether skin temperature asymmetry reflects muscle force imbalance in cycling. Therefore, the aim of this study was to assess whether a relationship exists between kinetic and thermal asymmetry during a fatiguing exercise. Ten elite cyclists were enrolled and tested on a maximal incremental cycling test. Peak crank torques of both legs were obtained at the initial and final workload. Likewise, bilateral skin temperatures were recorded before and after exercise. Asymmetric indexes were also calculated for kinetic (AIK) and skin temperature (AIT) outcomes. The bilateral peak crank torques showed a larger difference at the final compared to the initial workload (p < 0.05) of the incremental exercise. Conversely, the bilateral skin temperature did not show any differences at both initial and final workload (p > 0.05). Additionally, trivial relationships were reported between AIK and AIT (−0.3 < r < 0.2) at the initial and final workload. The obtained results showed that changes in bilateral kinetic values did not reflect concurrent changes in bilateral skin temperatures. This finding emphasizes the difficulty of associating the asymmetry of skin temperature with those of muscle effort in elite cyclists. Lastly, our study also provided further insights on thermal skin responses during exhaustive cycling exercise in very highly-trained athletes.

Change of direction asymmetry across different age categories in youth soccer

“…The testing sessions were arranged to assess sprint performance and COD ability in a randomized order. At the beginning of the session, each subject underwent a 5-minute warm-up period in a standardized process as previously adopted by Trecroci et al (2018b) . Immediately before each test, subjects were also invited to re-warm-up with skipping movements and dynamic stretching.…”

“…Change of direction (COD) actions (e.g., side-steps, swerves, turns, crossover steps, and by-pass maneuvers) are essential types of movements on the soccer pitch giving a player the chance to effectively evade or mark an opponent, to create space for his or her teammates, and to score a goal ( Hart et al, 2014 ; Rouissi et al, 2015 ; Trecroci et al, 2018b ). Performing an effective COD requires high lower limbs strength to manage rapid decelerations (producing eccentric force) and subsequent accelerations (producing concentric force) within a short time and in multiple directions ( Trecroci et al, 2018c ).…”

“…Beside observing meaningful differences between preferred and non-preferred directions of both COD deficit and total time, the authors also found that asymmetry percentage was greater for COD deficit than COD total time, indicating a different sensitivity between tests in detecting asymmetry-related differences. Moreover, the authors reported that for COD deficit almost half of the subjects exhibited asymmetries higher than 10%, a general threshold beyond that an individual’s asymmetry is considered substantial ( Dos’Santos et al, 2017 ; Trecroci et al, 2018b ). Given the importance of monitoring asymmetries during COD tasks in youth soccer, it remains unknown how they differ across age categories.…”

Association between physiological stress and skin temperature response after a half marathon

“…Therefore, some studies have used thermal stress protocols (for example, by applying cold), to analyze recovery, which is more influenced by alterations in the deeper tissues (Burkes In addition to the average skin temperature, we determined other measures for each ROI. The maximum temperature was determined by the maximum value observed within the ROI, which could be more sensitive to changes related to blood flow and inflammation (Ludwig et al 2014, Formenti et al 2018. The main limitation of this variable was that was calculated by a single pixel, and some researchers proposed other estimation from the average of the 125 warmest pixels in the ROI (called Tmax method) which presents less noise (Formenti et al 2018).…”

“…The maximum temperature was determined by the maximum value observed within the ROI, which could be more sensitive to changes related to blood flow and inflammation (Ludwig et al 2014, Formenti et al 2018. The main limitation of this variable was that was calculated by a single pixel, and some researchers proposed other estimation from the average of the 125 warmest pixels in the ROI (called Tmax method) which presents less noise (Formenti et al 2018). On the other hand, the standard deviation within the ROI was determined because it represents the temperature distribution within the ROI and could be affected by physical exercise (Ammer and Formenti 2016).…”