The Study
Training Characteristics and Power Profile of Professional U23 Cyclists throughout a Competitive Season (2020).
By Peter Leo, James Spragg, Dieter Simon, Justin Lawley and Iñigo Mujika
Full text article available here.
Background
In athletes with already high volumes of training, it becomes particularly important to have an appropriate manipulation of the training intensity distribution (TID), so that positive physiological adaptations can occur and athletes can continue to improve their performances as a result.
Training optimisation is, therefore, crucial if athletes are to maximize their chances of success. Analysing the training characteristics and power profile of athletes can be used to predict race performance, which ultimately leads to better training prescription and better distribution of training volume/intensity across the competitive season.
The purpose of this study was twofold: (1) to compare the power profile between training and racing to determine differences in the power profile derived from training data; and (2) analyse the variation in training characteristics across the competitive season and investigate the relationship between changes in training and changes in performance (power profile) of professional U23 cyclists.
Method
Thirty male U23 professional cyclists (VO2max: 73.7 ± 2.5 ml·kg-1·min-1) from a UCI Continental U23 development team. Riders were classified as allrounders (n = 21) and climbers (n = 9).
The season was split into 4 periods: pre-season (Nov to Jan), early-season (Feb to April), mid-season (May to July) and late-season (August to October).
Cyclists performed laboratory testing (to determine VO2max and maximal power output, Pmax) and field-based critical power testing (2, 5, 12 min mean maximal power, MMP) on a climb averaging 5.5% gradient. The 2 and 5 min efforts were carried out the same day, interspersed by 30 min recovery. Cyclists were encouraged to maintain a cadence of 80-100 rpm. Critical Power (CP) was calculated as the inverse of time model:
Where P = power output (W), W’ = W prime, work capacity above critical power, t = duration of field test (s)
Practical Applications: What can we learn from the study?
1) Don't use training data to predict power output in races
Absolute 2, 5 and 12 min MMP were significantly lower in training compared to racing for early-, mid- and late-season periods.
Critical power was also significantly higher in racing compared to training for early-, mid- and late-season periods (mean difference: 21 W, 29 W, 27 W, respectively).
This suggests that the power output cyclists can hold in training is going to be lower than what they are capable of sustaining in races/competitions.
Possible explanations:
- Residual fatigue accumulated during training undermines the cyclist’s true ability or potential.
- Athletes don’t need to push themselves to absolute exhaustion during training in order to induce positive physiological adaptations. High-intensity intervals are often prescribed at certain wattages, as opposed to all-out efforts for a given duration.
- Repeatability of high-intensity intervals. In training, cyclists must perform multiple work-bout intervals, interspersed with fixed recovery periods. In order to ensure that all intervals are performed at prescribed intensities, some form of pacing is required [i.e. (if performing 6 intervals at a given intensity) going all-out for the first 2 intervals, would compromise the quality of the remaining intervals]. This is necessary to ensure all intervals can be completed.
2) The racing stimulus is enough
Total work performed (kJ) increased during early season compared to pre-season (from 90,507 ± 45,622 to 132,825 ± 36,738 kJ, p = 0.002), as well as work·h-1 (from 529 ± 182 to 658 ± 143 kJ·h-1, p = 0.034). Time below VT1, between VT1-VT2 and above VT2 increased significantly from pre- to early-season (mean increases of 10 h, 20 h and 3.5 h respectively, all p<0.05).
Changes in 2 and 5 min MMP between pre- and early-season were significantly correlated with changes in total work performed (kJ) and work·h-1 (kJ·h-1) (see above). This significant albeit moderate negative relationship suggests that higher increases in training load leading up to the season’s first competitions is significantly related to negative changes in 2 and 5 min MMP. The cyclists that either maintained or improved their 2 and 5 min MMP were the ones who maintained or even slightly reduced their training load in preparation for the first races of the season.
There is a general misconception among coaches that training load during this period (through volume, intensity, or both) should be increased to account for the demands of racing. These findings appear to suggest that simply letting athletes settle into the demands of competition is enough to signal positive physiological adaptations and it may prove beneficial over the course of the competitive season and save them from unnecessary additional training stimulus.
3) Polarised training all-year round
More high-intensity sessions (or time spent above CP/LT2/VT2/MLSS/OBLA) does not equate to more fitness or power on the bike. There is a reason the polarised training approach is 80-0-20 and not 20-0-80! Time below LT1/VT1 not only matters, but is also crucial to maximize performance gains. Time spent at an intensity below LT1/VT1 was significantly correlated (moderate relationship) with positive changes in 2 and 5 min MMP during mid-season (see above, A+B). In turn, time spent above VT2/LT2 plays an important role in improvements seen in CP (see above, C).
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