A short self-paced submaximal test to monitor endurance cycling fitness

Abstract

Introduction Monitoring the cyclists’ responses to training is important for optimizing training and improving cycling performance (Galán-Rioja, Gonzalez-Ravé, González-Mohíno, & Seiler, 2023; Jeffries et al., 2021). However, this process can be costly and time-consuming. Submaximal fitness tests provide a practical alternative to traditional maximal tests, allowing the monitoring of training effects while minimizing disruptions to the athlete's training and competition schedule (Shushan et al., 2022).              

Recently, Sangan, Hopker, Davison, & McLaren (2021) proposed the self-paced submaximal run test (SRT_RPE) as a more practical form of the running version of the Lamberts and Lambert submaximal cycling test (LSCT) (Lamberts, Swart, Noakes, & Lambert, 2011). The LCST measures cycling power output (w) or running velocity (v) and ratings of perceived effort (RPE) during two 6-minute stages and one 3-minute stage of increasing intensity, which are determined by a fixed percentage of the maximum heart rate (Lamberts et al., 2011; Vesterinen et al., 2016). In contrast, the SRT_RPE monitors v and heart rate (HR_ex) during three 3-minute stages prescribed by RPE 10, 13, and 17 (Sangan et al., 2021).                 

The self-paced nature of the SRT_RPE makes it potentially more specific to the pacing demands of competition and, more importantly, less cumbersome since there is no requirement to collect and to store RPE data for later analysis, nor to do a prior maximal testing to establish the relative intensity of each stage. Furthermore, standardizing intensity by RPE could provide a better insight into the individual's responses to endurance training by reflecting more accurately individual differences in the exercise intensity domains (Iannetta et al., 2020; Seip, Snead, Pierce, Stein, & Weltman, 1991). Sangan et al. (2021) reported promising findings showing that v, at all stages of the SRT_RPE, was largely correlated with aerobic fitness parameters such as maximal oxygen uptake (VO_2max), v at VO_2max (vVO_2max), and v at lactate threshold 2 (vLT2). Moreover, test retest analysis showed acceptable reliability with coefficients of variation between 2.5% and 5.6% for v and HR_ex at all stages (Sangan et al., 2021).

Given the supportive findings and potential benefits of a self-paced design, the aim of our study was to evaluate the feasibility of a cycling-specific adaptation of the SRT_RPE protocol. The modified protocol incorporates the latest research on RPE and is tailored towards the specific requirements of road cycling (Ebert, Martin, Stephens, & Withers, 2006; Lopes, Pereira, & Silva, 2022). The self-paced submaximal cycling test (SCT_RPE) measures w and HR_ex responses during three 2-minute stages using Borg's CR100 scale (RPE Moderate, Hard, Very Hard) and evaluates neuromuscular function with one second peak power (w_sprint) and post-exercise heart rate recovery (HRR).

Materials and Methods Twenty-three trained to highly trained (29.6 ± 9.2 y, 72.7 ± 9.7 kg, VO_2peak 65.6 ± 7.1 ml∙kg-¹∙min-¹) endurance cyclists (including 3 females) received standardized RPE instructions and anchoring procedures. Then, they underwent the first trial of the SCT_RPE. They also performed three 6-second maximal sprints and a graded exercise test (GXT) to determine their maximal neuromuscular one second peak power (w_MAXsprint), ventilatory thresholds (VT1, VT2), peak oxygen consumption (VO_2peak), and peak power (w_peak). Within a period of 2 to 14 days, the participants completed two additional trials of the SCT_RPE to evaluate the test-retest reliability of HRR, w_sprint, HR_ex, and w at each stage of the test. Correlations were used to examine the relationship between the SCT_RPE and the parameters measured during the GXT to establish convergent validity.   Results Power output measured during all stages of the SCT_RPE had moderate to very large correlations with the parameters measured during the GXT, ranging from .48-.85. Notably, the highest correlation (r = .85) was observed between w_peak and w at RPE Very Hard (Figure 2). The intraclass correlation coefficients (ICC_3,1) for w and HR_ex at all stages of the SCT_RPE ranged from .86-.92, indicating high to very high reliability, with typical errors (TEs) ranging from 2.7% to 7.9% (Table 1). The reliability of HRR expressed as a percentage of the peak heart rate recorded during the trial (HRR_%hrpeak) and w_sprint was found to be moderate and very high, respectively, with ICC_3,1 value of .74 and .93, and TEs of 4.4% and 6.7% (Table 1). Conclusions

The study findings suggest that the SCT_RPE is a reliable and valid measure of endurance cycling fitness. The high intraclass correlation coefficients and good convergent validity with the parameters of the GXT, particularly w_peak, indicate that the SCT_RPE could be an effective and practical test to monitor endurance cycling athletes’ responses to training. 

Practical Applications

Athletes and coaches using the SCT_RPE may be able to observe changes in training status when the power output exceeds the TE measured for each stage. For example, if the power output of a cyclist during the last stage (RPE Very Hard) of the SCT_RPE exceeds by 25W his power output of the previous test, we can assume that his cycling fitness is rising because the change is greater than the TE of 22W for this stage.