Consistency of commercial devices for measuring elevation gain

Differences in training characteristics between junior, under 23 and professional cyclists

The aim was to compare the training characteristics of junior, under 23 and professional road cyclists. Training data collected during the 2019 competitive season of thirty male cyclists, divided into three age-related categories (JUN; U23; PRO), were retrospectively analyzed for training characteristics, external and internal training load. Higher duration per training session were observed in PRO (2.6 ± 0.3 h) compared to both U23 (2.2 ± 0.3 h; P < 0.001) and JUN (2.0 ± 0.2 h; P < 0.001). Elevation gain per distance was higher in PRO (13.8 ± 1.9 m⋅km-1) compared to U23 (10.6 ± 0.9 m⋅km-1; P = 0.001) and JUN (6.7 ± 0.3 m⋅km-1; P < 0.001), and in U23 compared to JUN (P < 0.001). Annual total work was lower in JUN (3694 ± 467 kJ⋅kg-1) compared to U23 (5268 ± 746 kJ⋅kg-1; P = 0.001) and PRO (5759 ± 1103 kJ⋅kg-1; P < 0.001). eTRIMP per hour was higher in JUN (151 ± 40) compared to both U23 (115 ± 23; P = 0.003) and PRO (112 ± 22; P = 0.013). JUN spent more training time at medium and high heart rate intensity zones compared to U23 and PRO (P < 0.05).

Cross-Sectional Differences in Race Demands Between Junior, Under 23, and Professional Road Cyclists

PURPOSE

To compare the race demands of junior (JUN), under 23 (U23), and professional (PRO) road cyclists.

METHODS

Thirty male cyclists, divided into 3 age-related categories (JUN, n = 10; U23, n = 10; and PRO, n = 10), participated in this study. Race data collected during the 2019 competitive season were retrospectively analyzed for race characteristics, external, and internal competition load.

RESULTS

Higher annual and per race duration, distance, elevation gain, Edward's training impulse, total work, and work per hour were observed in PRO versus U23 and JUN, and U23 versus JUN (P < .01). PRO and U23 recorded higher mean maximal power (RPOs) between 5 and 180 minutes compared with JUN (P < .01). Edward's training impulse per hour was higher in JUN than PRO and U23 (P < .01). Accordingly, JUN spent a higher percentage of racing time in high internal intensity zones compared with U23 and PRO, while these 2 categories spent more time at low internal intensity zones (P < .01).

CONCLUSIONS

JUN races were shorter and included less elevation gain per distance unit compared to U23 and PRO races, but more internally demanding. JUN produced less power output in the moderate-, heavy-, and severe-intensity exercise domains compared with U23 and PRO (RPOs: 5-180 min). U23 and PRO races presented similar work demands per hour and RPOs, but PRO races were longer than U23.

Review of Validity and Reliability of Garmin Activity Trackers

Purpose

A systematic review to summarize the validity and reliability of steps, distance, energy expenditure, speed, elevation, heart rate, and sleep assessed by Garmin activity trackers.

Methods

Searches included studies published through December 31, 2018. Correlation coefficients (CC) were assessed as low (<0.60), moderate (0.60-<0.75), good (0.75-<0.90), or excellent (>=0.90). Mean absolute percentage errors (MAPE) were assessed as acceptable at <5% in controlled conditions and <10% for free-living.

Results

Overall, 32 studies of adults documented validity. Four of these studies also documented reliability. The sample size ranged from 1 to 95 for validity and 4 to 31 for reliability testing. Step inter- and intra-reliability was good-to-excellent and speed intra-reliability was excellent. No other features were explored for reliability. Step validity, across 16 studies, generally indicated good-to-excellent CC and acceptable MAPE. Distance validity, tested in three studies, generally indicated poor CC and MAPE that exceeded acceptable limits, with both over and underestimation. Energy expenditure validity, across 12 studies, generally indicated wide variability in CC and MAPE that exceeded acceptable limits. Heart rate validity in five studies had low-to-excellent CC and all MAPE exceeded acceptable limits. Speed, elevation, and sleep validity were assessed in only one or two studies each; for sleep, the criterion relied on self-report rather than polysomnography.

Conclusion

This systematic review of Garmin activity trackers among adults indicated higher validity of steps; few studies on speed, elevation, and sleep; and lower validity for distance, energy expenditure, and heart rate. Intra- and inter-device feature reliability needs further testing.

Demands of World Cup Competitions in Elite Women's Road Cycling

PURPOSE

To describe the demand of recent World Cup (WC) races comparing top-10 (T10) and non-top-10 (N-T10) performances using power data.

METHODS

Race data were collected in 1-d World Cup races during the 2012-2015 road cycling seasons. Seven female cyclists completed 49 WC races, finishing 25 times in T10 and 24 times in N-T10. Peak power (1 s) and maximal mean power (MMP) for durations of 5, 10, 20, and 30 s and 1, 2, 5, 10, 20, 30, and 60 min expressed as power to weight ratio were analyzed in T10 and N-T10. The percentage of total race time spent at different power bands was compared between T10 and N-T10 using 0.75-W·kg^-1 power bands, ranging from <0.75 to >7.50 W·kg^-1. The number of efforts in which the power output remained above 7.50 W·kg^-1 for at least 10 s was recorded.

RESULTS

MMPs were significantly higher in T10 than in N-T10, with a large effect size for durations between 10 s and 5 min. N-T10 spent more time in the 3.01- to 3.75-W·kg^-1 power band when compared to T10 (P = .011); conversely, T10 spent more time in the 6.75- to 7.50- and >7.50-W·kg^-1 power bands (P = .009 and .005, respectively) than N-T10. A significantly higher number of short and high-intensity efforts (≥10 s, >7.5 W·kg^-1) was ridden by T10 than N-T10 (P = .002), specifically, 46 ± 20 and 30 ± 15 efforts for T10 and N-T10, respectively.

CONCLUSIONS

The ability to ride at high intensity was determinant for successful road-cycling performances in WC races.

The influence of the gait-related arm swing on elevation gain measured by sport watches

The elevation gain is an important contributor to the total workload in endurance sports. The purpose of this study was to evaluate the influence of the arm swing on elevation gain in three sport watches (Garmin® Forerunner 910XT, Polar® RS800CX and Suunto® Ambit2) on a flat 400 m outdoor track. Altogether, a total of 120 repetitions of 1,200 m were performed at self-selected speeds corresponding to strolling, walking, jogging and running. During the assessment two devices of each sport watch, one secured on the hip and one on the wrist, were worn by the participants. A small but significant (effect size = .39; p < .001) influence of the arm swing on elevation was revealed in all sport watches. Elevation indication errors recorded on the wrist were significantly larger than the ones recorded on the hip (4.0-7.4 vs. 1.2-5.7 m per 1,200 m; p < .05). Furthermore, when wearing the devices on the wrist, errors in elevation indication increased when gait speed increased. Users should be aware that wearing the devices on the hip can significantly decrease measurement errors. This might be especially relevant for activities with high dynamics, such as jogging and running.

Impact of Altitude on Power Output during Cycling Stage Racing

PURPOSE

The purpose of this study was to quantify the effects of moderate-high altitude on power output, cadence, speed and heart rate during a multi-day cycling tour.

METHODS

Power output, heart rate, speed and cadence were collected from elite male road cyclists during maximal efforts of 5, 15, 30, 60, 240 and 600 s. The efforts were completed in a laboratory power-profile assessment, and spontaneously during a cycling race simulation near sea-level and an international cycling race at moderate-high altitude. Matched data from the laboratory power-profile and the highest maximal mean power output (MMP) and corresponding speed and heart rate recorded during the cycling race simulation and cycling race at moderate-high altitude were compared using paired t-tests. Additionally, all MMP and corresponding speeds and heart rates were binned per 1000 m (<1000 m, 1000-2000, 2000-3000 and >3000 m) according to the average altitude of each ride. Mixed linear modelling was used to compare cycling performance data from each altitude bin.

RESULTS

Power output was similar between the laboratory power-profile and the race simulation, however MMPs for 5-600 s and 15, 60, 240 and 600 s were lower (p ≤ 0.005) during the race at altitude compared with the laboratory power-profile and race simulation, respectively. Furthermore, peak power output and all MMPs were lower (≥ 11.7%, p ≤ 0.001) while racing >3000 m compared with rides completed near sea-level. However, speed associated with MMP 60 and 240 s was greater (p < 0.001) during racing at moderate-high altitude compared with the race simulation near sea-level.

CONCLUSION

A reduction in oxygen availability as altitude increases leads to attenuation of cycling power output during competition. Decrement in cycling power output at altitude does not seem to affect speed which tended to be greater at higher altitudes.