Aerobic exercise intensity does not affect the anabolic signaling following resistance exercise in endurance athletes

Abstract

This study examined whether intensity of endurance stimulus within a concurrent training paradigm influenced the phosphorylation of signaling proteins associated with the mTOR and AMPK networks. Eight male cyclists completed (1) resistance exercise (RES), 6 × 8 squats at 80% 1-RM; (2) resistance exercise and moderate intensity cycling of 40 min at 65% V̇O2peak, (RES + MIC); (3) resistance exercise and high intensity interval cycling of 40 min with 6 alternating 3 min intervals of 85 and 45% V̇O2peak (RES + HIIC), in a cross-over design. Muscle biopsies were collected at rest and 3 h post-RES. There was a main effect of condition for mTORS2448 (p = 0.043), with a greater response in the RES + MIC relative to RES condition (p = 0.033). There was a main effect of condition for AMPKα2T172 (p = 0.041), with a greater response in RES + MIC, relative to both RES + HIIC (p = 0.026) and RES (p = 0.046). There were no other condition effects for the remaining protein kinases assessed (p > 0.05). These data do not support a molecular interference effect in cyclists under controlled conditions. There was no intensity-dependent regulation of AMPK, nor differential activation of anabolism with the manipulation of endurance exercise intensity.

Effects of Cycling Intensity on Acute Signaling Adaptations to 8-weeks Concurrent Training in Trained Cyclists

“…All documentation and procedures were approved by the institutional research ethics committee, in accordance with the Declaration of Helsinki. Eight of the thirteen cyclists who participated in the present study, also participated in an acute repeated measures cross over study investigating the acute effects of the intensity of endurance stimuli on the phosphorylation of signaling proteins associated with the mTOR and AMPK networks ( Jones et al, 2021 ). Within said acute study all participants completed three independent and different single exercise sessions on separate occasions, with no longitudinal intervention nor pre- and post-intervention assessments.…”

“…Detailed information on the protocols employed here is presented in Jones et al ( Jones et al, 2021 ). Briefly, an incremental lactate threshold (LT) assessment was conducted prior to the V̇O 2peak test, with the starting intensity selected (range: 125–200 W) with subsequent increases in the work rate of 25 W every 4 min.…”

“…Detailed information on the protocols employed here is presented in Jones et al ( Jones et al, 2021 ). Briefly, for 24 h prior to an experimental trial, participants refrained from structured exercise and consumed a standardized diet.…”

“…The exercise of 3 min intervals of 85 and 45% V̇O 2peak provided a total mechanical work matched high intensity intervention ( Seiler and Tønnessen 2009 ). Both protocols contained a warm-up and cool down and are presented in Jones et al ( Jones et al, 2021 ). Heart rate was recorded throughout each trial, while visual feedback of time elapsed, power output, and pedal cadence were made available to participants.…”

“…However, the relevance of AMPK activation status should be treated with caution, as there are data to suggest that AMPK phosphorylation does not inhibit acute growth-related responses after subsequent strength stimuli in moderately trained males ( Apró et al, 2015 ). Furthermore, recent work has reported similar anabolic signaling responses following combined strength and high- and moderate intensity endurance exercise in endurance trained cyclists ( Jones et al, 2021 ), and that interference characteristics may be avoided if high intensity interval type endurance training is implemented alongside strength training ( Vechin et al, 2021 ).…”