Author(s): BLECHSCHMIED, R.1, RÖCKER, K.2, CENTNER, C.1, GIRARD, O.3, GRANACHER, U.1, Institution: UNIVERSITY OF FREIBURG, Country: GERMANY, Abstract-ID: 642

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.