This study investigated biomechanical assessments in trail running, comparing two wearable devices—Stryd Power Meter and GARMIN_RP. With the growing popularity of trail running and the complexities of varied terrains, there is a heightened interest in understanding metabolic pathways, biomechanics, and performance factors. The research aimed to assess the inter- and intra-device agreement for biomechanics under ecological conditions, focusing on power, speed, cadence, vertical oscillation, and contact time. The participants engaged in trail running sessions while wearing two Stryd and two Garmin devices. The intra-device reliability demonstrated high consistency for both GARMIN_RP and Stryd^TM, with strong correlations and minimal variability. However, distinctions emerged in inter-device agreement, particularly in power and contact time uphill, and vertical oscillation downhill, suggesting potential variations between GARMIN_RP and Stryd^TM measurements for specific running metrics. The study underscores that caution should be taken in interpreting device data, highlighting the importance of measuring with the same device, considering contextual and individual factors, and acknowledging the limited research under real-world trail conditions. While the small sample size and participant variations were limitations, the strength of this study lies in conducting this investigation under ecological conditions, significantly contributing to the field of biomechanical measurements in trail running.

Background: Vertical kilometer is an emerging sport where athletes continuously run uphill. The aims of this study were to assess changes in vertical impacts caused by uphill running (UR) and the relation between the anthropometric and lower limb muscular characteristics with speed. Methods: Ten male experienced runners (35 ± 7 years old) participated in this study. In the racetrack (4.2 km long, 565 m high), seven sections were stablished. Mean speed and impact value of sections with similar slope (≈21%) were calculated. The gastrocnemius stiffness (GS) and tone (GT); and the vastus lateralis stiffness (VS) and tone (VT) were assessed before the race. Results: Pearson’s correlation showed a linear relationship between vs. and VT (r = 0.829; p = 0.000), GT and GS (r = 0.792; p = 0.001). Mean speed is correlated with weight (r = −0.619; p = 0.024) and GT (r = 0.739; p = 0.004). Multiple linear regressions showed a model with weight and GT as dependent variables of mean speed. Mean impacts decreased significantly between sections along the race. Conclusions: The vertical impacts during UR were attenuated during the race. Moreover, body weight and GT were associated with the time-to-finish, which supports that low weight alone could not be enough to be faster, and strength training of plantar flexors may be a determinant in UR.

Goalball is a sport for visually impaired athletes, where the roles of attack and defense change continuously during the game. Performance evaluation should consider the variables that determine the throwing and the stop and clearance of the ball. The aim of this study is to evaluate the precision and velocity of the ball throwing in goalball, besides core stability and balance as variables that determine an optimal throwing. Moreover, a novel acoustic reaction time is applied to analyze the defense performance. Eight goalball players (33 ± 9 years old; 77.8 ± 22.7 kg; 174 ± 13 cm; 10 ± 5 years of experience) were recruited to assess ball velocity, with a radar gun, and throwing accuracy. Anthropometry, static balance, and core stability were assessed using a computerized pressure platform. Acoustic reaction time was measured with a photoelectric system. A significant positive correlation was found between throwing speed and the years of experience (Ƿ = 0.714, p = 0.047), height (Ƿ = 0.786, p = 0.021), dominant leg surface area of the stabilogram (Ƿ = 0.738, p = 0.037), and non-dominant leg center of pressure mean velocity (Ƿ = 0.714, p = 0.017). In the present pilot study, height and years of experience are correlated to throwing velocity. This is also the first test proposal to assess throwing precision and complex acoustic reaction in goalball players, which could be used to assess the level of performance in future studies.

New and promising variables are being developed to analyze performance and fatigue in trail running, such as mechanical power, metabolic power, metabolic cost of transport and mechanical efficiency. The aim of this study was to analyze the behavior of these variables during a real vertical kilometer field test. Fifteen trained trail runners, eleven men (from 22 to 38 years old) and four women (from 19 to 35 years old) performed a vertical kilometer with a length of 4.64 km and 835 m positive slope. During the entire race, the runners were equipped with portable gas analyzers (Cosmed K5) to assess their cardiorespiratory and metabolic responses breath by breath. Significant differences were found between top-level runners versus low-level runners in the mean values of the variables of mechanical power, metabolic power and velocity. A repeated-measures ANOVA showed significant differences between the sections, the incline and the interactions between all the analyzed variables, in addition to differences depending on the level of the runner. The variable of mechanical power can be statistically significantly predicted from metabolic power and vertical net metabolic COT. An algebraic expression was obtained to calculate the value of metabolic power. Integrating the variables of mechanical power, vertical velocity and metabolic power into phone apps and smartwatches is a new opportunity to improve performance monitoring in trail running.

Article: Modifications of viscoelastic properties and physiological parameters after performing uphill and downhill running trials - The Journal of Sports Medicine and Physical Fitness 2021 May;61(5):625-35 - Minerva Medica - Journals

Exercise, despite being a beneficial activity for health, can also be a source of oxidative imbalance, which can lead to a decrease in performance. Furthermore, melatonin is an endogenous molecule that may counteract exercise-induced oxidative stress. The aim of this study was to evaluate the potential ergogenic and antioxidant capacity of melatonin administered for a maximal effort test. A total of 30 rats were divided into three groups—control, exercise, and exercise + melatonin (intraperitoneal administration of 10 mg/kg)—to assess the effects of an exhaustive incremental protocol in the two exercise groups (with and without melatonin) on the treadmill-running performance (final speed reached), lipid and protein oxidation markers (malondialdehyde + 4-hidroxyalkenals and carbonyl content, respectively), and cellular and mitochondrial membranes’ fluidity in skeletal muscle, brain, and liver tissues. Our results show an ergogenic effect of melatonin (31 ± 4 vs. 36 ± 4 cm/s), which may be due to its antioxidant properties being significantly stronger than its protective effect when performing increasing exercise on a treadmill until exhaustion. Melatonin reverted the membrane rigidity in the brain caused by exercise (with no effect on muscle or liver), prevented lipid oxidation in muscle, and prevented lipid and protein oxidation in the liver. Differences between tissues’ responses to exercise and melatonin need to be investigated in the future to elucidate other possible mechanisms that explain melatonin’s ergogenic effect.