Author(s): VILLANOVA, S., FUK, A., SPARNERI, L., PODDA, F., QUAGLIAROTTI, C., GRAMAZIO, A., DELLO STRITTO, E., CONTI, A., BAZZUCCHI, I., PORCELLI, S., PIACENTINI, M.F., Institution: UNIVERSITY OF ROME “FORO ITALICO, Country: ITALY, Abstract-ID: 1976

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