Field-Derived Maximal Power Output in Cycling: An Accurate Indicator of Maximal Performance Capacity?

Is the 5-Minute Time-Trial Cycling Test a Valid Predictor of Maximal Oxygen Uptake? An External Cross-Validation Study

PURPOSE

This study aimed to cross-validate a recently proposed equation for the prediction of maximal oxygen uptake (V˙O2max) in cycling exercise by using the average power output normalized by the body mass from a 5-minute time trial (RPO5-min) as the independent variable. Further, the study aimed to update the predictive equation using Bayesian informative prior distributions and meta-analysis.

METHODS

On different days, 49 male cyclists performed an incremental graded exercise test until exhaustion and a 5-minute time trial on a stationary cycle ergometer. We compared the actual V˙O2max with the predicted value obtained from the RPO5-min, using a modified Bayesian Bland-Altman agreement analysis. In addition, this study updated the data on the linear regression between V˙O2max and RPO5-min, by incorporating information from a previous study as a Bayesian informative prior distribution or via meta-analysis.

RESULTS

On average, the predicted V˙O2max using RPO5-min underestimated the actual V˙O2max by -6.6 mL·kg-1·min-1 (95% credible interval, -8.6 to -4.7 mL·kg-1·min-1). The lower and upper 95% limits of agreement were -17.2 (-22.7 to -12.3) and 3.8 (-1.0 to 9.5) mL·kg-1·min-1, respectively. When the current study's data were analyzed using the previously published data as a Bayesian informative prior distribution, the accuracy of predicting sample means was found to be better when compared with the data combined via meta-analyses.

CONCLUSIONS

The proposed equation presented systematic bias in our sample, in which the prediction underestimated the actual V˙O2max. We provide an updated equation using the previous one as the prior distribution, which could be generalized to a greater audience of cyclists.

Is all work the same? Performance after accumulated work of differing intensities in male professional cyclists

OBJECTIVES

Although the ability to attenuate power output (PO) declines after accumulated work (i.e., 'durability') is increasingly recognized as a major determinant of cycling performance, the potential role of the intensity of the previous work is unclear. We assessed the effect of work-matched levels of accumulated work at different intensities on performance in male professional cyclists.

DESIGN

Observational field-based study.

METHODS

PO data was registered in 17 cyclists during a competition season, and the critical power (CP) was repeatedly determined every 4 weeks from training sessions and competitions. Participants' maximum mean power (MMP) for different durations (5 s, 5 min, 10 min, and 20 min) and the CP were determined under 'fresh' conditions (0 kJ·kg-1) and after varying levels of accumulated work (2.5, 5.0 and 7.5 kJ·kg-1) at intensities below and above the CP.

RESULTS

A significant decline was found for all MMP values following all levels of accumulated work above the CP (-4.0 %, -1.7 %, -1.8 %, and -3.2 % for 30s, 5 min, 10 min and 20 min-MMP, respectively; all p < 0.001), versus no change after any level of accumulated work below the CP (all p > 0.05). Similar results were observed for the CP, which decreased after all levels of accumulated work above (-2.2 %, -6.1 %, and -16.2 %, after 2.5, 5.0 and 7.5 kJ·kg-1, p < 0.001) but not below this indicator (p > 0.05).

CONCLUSIONS

In male professional cyclists, accumulated work above the CP impairs performance compared with work-matched, albeit less intense efforts. This raises concerns on the use of mechanical work per se as a single fatigue/stress indicator in these athletes.

Influence of Conventional Resistance Training Compared to Core Exercises on Road Cycling Power Output

Conventional strength training and core exercises are commonly prescribed to improve cycling performance. Although previous studies have explored the utility of strength training in various cycling populations, this intervention has never been compared to core exercises. Thirty-six trained road cyclists were divided into three groups of 12 participants that performed either no strength training, conventional strength training, or core exercises, in all cases together with their regular cycling training during a 12-week period. Peak power outputs (POs) across different durations (five seconds, 60 seconds, five minutes, and 20 minutes) were recorded before and after the intervention. The results of the present study showed higher increases in relative PO with conventional strength training when compared to core training and no strength training for all measured durations: five-second Δ = 1.25 W/kg vs 0.47 W/kg and -0.17 W/kg; 60-second (Δ = 0.51 W/kg vs 0.13 W/kg and 0.02 W/kg; five-minute Δ = 0.22 W/kg vs 0.06 W/kg and 0.05 W/kg; and 20-minute Δ = 0.22 W/kg vs 0.07 W/kg and 0.06 W/kg. According to the data obtained in this study, conventional strength training is superior to core exercises, and no strength training was performed by trained road cyclists. Accordingly, it is recommended that this population incorporates strength training during their regular weekly workouts.

The Tour de France, also possible for mortals? A comparison of a recreational and a World Tour cyclist

Cycling Grand Tours are arguably the epitome of strenuous endurance exercise, and they have been reported to represent the ceiling of sustained energy expenditure for humans. It remains unknown, however, if an average recreational athlete could endure such an event. Through the analysis of power output (PO), we compared data from the 2023 Tour de France (21 stages, total distance = 3,405 km, elevation gain = 51,815 m) in a recreational (male, age = 58 yr; height = 191 cm; body mass = 96.1 kg; estimated maximum oxygen uptake = 45.4 mL·kg-1·min-1) and a sex-matched professional (World-Tour) cyclist (28 yr; 180 cm; 67.0 kg; 80.5 mL·kg-1·min-1). The recreational and professional cyclist completed the event in 191 and 87 h, respectively (average PO of 1.50 and 3.45 W·kg-1), with the latter spending a greater proportion of time in high-intensity zones. The recreational cyclist showed an estimated total daily energy expenditure (TDEE) of 35.9 MJ [or 8,580 kcal, or ∼4.3× his daily basal metabolic rate (BMR)], whereas lower absolute values were estimated for the professional cyclist (29.7 MJ, 7,098 kcal, ∼3.8× his BMR). Despite such high TDEE values, both individuals lost minimal body mass during the event (0-2 kg). The present report therefore suggests that, partly due to differences in exercise intensity and duration, not only professional cyclists but also recreational athletes can reach currently known ceilings of TDEE for humans.NEW & NOTEWORTHY This case report indicates that a recreationally trained 58-year-old man can reach similar or even higher values of energy expenditure (∼4 times their basal metabolic rate) than professional cyclists, who are likely near the ceiling of sustained energy expenditure for humans. This was possible owing to a total longer exercise time coupled with a lower absolute and relative intensity in the recreational athlete.

Between-Seasons Variability of Cyclists' Peak Performance: A Longitudinal Analysis of "Real-World" Power Output Data in Male Professional Cyclists

PURPOSE

The record power profile (RPP) has gained popularity as a method of monitoring endurance cycling performance. However, the expected variation of cyclists' performance between seasons remains unknown. We aimed to assess the between-seasons variability of peak performance (assessed through the RPP) in male professional cyclists.

METHODS

The study followed a longitudinal observational design. Sixty-one male professional cyclists (age 26 [5] y) with power output data from both training sessions and competitions were analyzed for a median of 4 consecutive seasons (range 2-12). The highest mean maximum power values attained for different durations (from 10 s to 30 min), as well as the resulting critical power, were determined for each season. Within-cyclist variability between seasons was assessed, and the upper threshold of expected changes (ie, twice the normal coefficient of variation) was determined.

RESULTS

All mean maximum power values showed an overall high agreement and low variability between seasons (intraclass correlation coefficient [ICC] = .76-.88 and coefficient of variation [CV] = 3.2%-5.9%), with the lowest variability observed for long efforts (>1 min). Critical power showed an ICC and CV of .79 (95% CI, .70-.85) and 3.3% (95% CI, 3.0%-3.7%), respectively. Upper thresholds of expected variation were <12% for short efforts (≤1 min) and <8% for long efforts.

CONCLUSIONS

"Real-world" peak performance assessed through the RPP shows a low variability between seasons in male professional cyclists-especially for long efforts-with expected variation being around 6% and 3% for short (≤1 min) and long efforts, respectively, and with changes >12% and >8%, respectively, being infrequent for these effort durations.