ECSS Paris 2023: OP-AP04
INTRODUCTION: Strength training (ST) improves exercise economy and performance in endurance athletes (1). However, excessive hypertrophic stimuli or poorly managed concurrent interventions may lead to negative effects, especially in triathletes with high endurance training (ET) volume(2,3). The study aimed to compare the effect of a minimal dose ST intervention (SNACK) with a traditional program (TRAD) on physiological parameters related to performance in trained triathletes, with the hypothesis that SNACK would not be inferior to traditional ST. METHODS: Twenty-three trained triathletes (age: 37±6yr; VO₂peak: 50.6±7 mL· kg⁻¹·min⁻¹) with no prior experience in ST were randomly assigned to either a TRAD (9M, 3F) or a SNACK (7M, 4F) 10-week ST program. ST was performed twice weekly and consisted of back squat, single-leg press, and calf raises at 75-85% of their one-rep maximum (1RM). SNACK volume (number of sets) was ~50% lower than TRAD. ET was matched between groups (~10h·wk⁻¹). Before and after training, assessments included 1RM back squat, cycling (CE) and running economy (RE) calculated from constant-intensity exercises, and lactate threshold (LT), lactate turnpoint (LTP), and VO₂peak from an incremental test. Performance was evaluated via a simulated Olympic distance triathlon: 1.5km of swimming (SWIM) at 85% of critical speed, 1h cycling (BIKE) at a mean power output of 65% maximal aerobic power (MAP), including 30 efforts (85–140% MAP) from 10 to 90s, and 10km run time trial (RUN). Time, condition, and time x condition interactions were tested by a two-way repeated-measures ANOVA (α<0.05). Non-inferiority (4) of SNACK vs TRAD was evaluated on two primary outcomes (1RM and exercise economy) using a prespecified non-inferiority margin (ΔNI: +8kg for 1RM; -0.15 mL·O₂·min⁻¹·W⁻¹ for exercise economy). RESULTS: 1RM improved in both groups, showing SNACK not inferior to TRAD (+18.5±4.7% vs +17.6±5.6%, p<0.001). CE improved after the interventions, resulting in SNACK not inferior to TRAD (-6.3±2.7% vs -4.8±4.1%, p<0.05). RE, LT, LTP, and VO₂peak did not change in any groups. Before training, SWIM time was (26.4±5.1min) in SNACK and (28.1±5.1min) in TRAD with no changes after the interventions. A time effect was observed for mean power output during BIKE (+7.9±4.8watt in SNACK; +7.0±6.4watt in TRAD; all, p<0.05) and RUN time (-1.4±1.1min in SNACK; -2.0±1.9min in TRAD; all, p<0.05), with no condition effect or interaction. CONCLUSION: In trained triathletes, a 10-week 'minimal dose' strength program (50% of standard volume) focused on the lower limbs improved BIKE and RUN performance, resulting also not inferior to a traditional ST intervention in improving maximal strength and cycling economy. Coaches looking to optimize physiological parameters related to race performance should consider time-efficient strength interventions, especially for athletes already managing high-volume endurance loads. 1.Beattie K et al.2014 2.Bishop D et al.2018 3.Sandbakk Ø, et al.2025 4.Mazzolari R, et al.2022
Read CV SIMONE VILLANOVAECSS Paris 2023: OP-AP04
INTRODUCTION: Performance in Olympic cross-country mountain biking is largely determined by aerobic and anaerobic capacity, lower-limb strength and power. In trained athletes, remaining adaptive reserves for resistance training are often limited by high training volumes and associated mechanical loads. Low-load blood flow restriction (BFR) training has been proposed as an alternative to high-load resistance (HL) training, as it may induce adaptations at substantially lower mechanical loads. However, evidence regarding its effectiveness in trained mountain bikers, particularly compared with the current HL standard, remains limited. Therefore, this study compared the effects of BFR and HL training on lower-limb strength, power, aerobic, anaerobic capacity, and cycling performance in male mountain bikers. METHODS: Twenty-eight trained (Tier 2) male mountain bikers were randomly assigned in age-matched pairs to an HL group (n = 13) or a BFR group (n = 15). Both groups completed two lower-limb resistance training sessions per week over an eight-week training period, in addition to their bike-specific training. The HL group trained at 70–85% of the one-repetition maximum (1RM), whereas the BFR group exercised at 20–30% of the 1RM with BFR applied at 60% of individual total limb occlusion pressure. Session rating of perceived exertion was assessed using the Borg scale (6–20). Pre- and post-intervention, assessments included maximal leg strength and power assessed using an instrumented leg press. Aerobic and anaerobic capacity were evaluated using an incremental ramp test with lactate diagnostics on a cycling ergometer. Anaerobic glycolytic capacity was further assessed using a Wingate test. Lastly, cycling performance was evaluated during a stationary 3.6-km time trial (4.1% average grade), simulated by resistance in Watts at maximal self-paced intensity via gear shifting. RESULTS: Perceived exertion over the training period did not differ significantly between groups (p > 0.05). Significant group-by-time interactions were observed for peak power output at the lactate thresholds (aerobic [LT]: p = 0.019, Cohen’s d = 0.98; anaerobic [IAT]: p = 0.019, d = 0.98) and mean time-trial power output (p = 0.007, d = 1.27), with improvements following BFR training (LT +19.6%, p = 0.001, d = 1.0; IAT +16.5%, p < 0.001, d = 1.43; time-trial +12.4%, p = 0.003, d = 1.0), whereas no significant changes were observed in the HL group. Significant main time effects were detected for maximal leg strength, power, Wingate power, and performance during the time-trial. CONCLUSION: In trained male mountain bikers, BFR training resulted in significant improvements in peak power output at LT and IAT as well as in average time-trial power, while no significant changes were detected after HL training. Accordingly, these findings support its use as a viable low-mechanical-load training strategy that may complement training in competitive mountain biking.
Read CV Roland BlechschmiedECSS Paris 2023: OP-AP04
INTRODUCTION: Heart-rate variability (HRV) reflects cardiac autonomic modulation and is widely used to monitor training stress and recovery in athletes [1]. The root mean square of successive differences (rMSSD) is particularly sensitive to perturbations in vagal-related activity during short, intensive periods [2]. However, in elite athletes, rMSSD may show a weak or non-linear association with external training load, partly due to complex autonomic regulation and potential "vagal saturation" [2]. Accordingly, brief psychometric questionnaires are gaining popularity as complementary, non-invasive monitoring tools [3][4]. This study aimed to examine the relationship between rMSSD and the Short Recovery and Stress Scale (SRSS) before and during world-level stage races in elite women cyclists. METHODS: Twenty-five elite women cyclists (twenty-one competing in the Giro d'Italia Women 2025 and seven in Le Tour de France Femmes 2025, with some athletes participating in both events) recorded morning HRV immediately upon waking using HRV4Training [5] and completed the SRSS [3] via mobile devices. Missing HRV metrics or the questionnaire data were excluded, yielding a final dataset of 308 complete entries. Associations between log-transformed rMSSD (lnrMSSD) and subjective measures were analyzed using generalized additive mixed models (GAMMs) to test for non-linear effects (edf>1.5). Subsequently, if GAMMs found a nonlinear relationship, the quadratic relationship was tested using linear mixed models (LMMs) with random slopes to account for inter-individual variability and provide a parametric interpretation. RESULTS: GAMMs identified a significant non-linear association between perceived stress and lnrMSSD (edf=2.68, p<0.05), whereas no association was observed between perceived recovery and lnrMSSD (p=0.18). LMMs with random slopes by athletes supported a quadratic effect (inverted-U) of perceived stress and lnrMSSD (linear and quadratic terms p<0.05), providing parametric confirmation of the non-linear pattern. Conditional R2 indicated that 70.5% of variability in lnrMSSD was explained by between-athlete differences, while marginal R2 for fixed effects was low (1.9%) highlighting pronounced individual specificity in autonomic responses. Perceived stress was the only subjective measure associated with the non-linear lnrMSSD response, whereas recovery scores were not associated with HRV. CONCLUSION: Perceived stress was non-linearly related to lnrMSSD, exhibiting an inverted-U pattern with lower lnrMSSD values at both low and high levels of perceived stress. These findings emphasize the need for individual and non-linear approaches to athlete monitoring, particularly during elite races. 1. Lundstrom et al., 2023 https://doi.org/10.1055/a-1864-9726 2. Schmitt et al., 2015 https://doi.org/10.3389/fphys.2015.00343 3. Kölling et al., 2020 https://doi.org/10.1080/02640414.2019.1684790 4. Esco et al., 2026 https://doi.org/10.3390/s26010003 5. Altini & Amft, 2016 https://doi.org/10.1109/EMBC.2016.7591265
Read CV Andrea ColomboECSS Paris 2023: OP-AP04