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Predicting the Efficacy of Resistance Exercise Training for Improving Endurance Performance

Not Applicable
Completed
Conditions
Elite Cyclists
Interventions
Behavioral: Endurance training (habitual)
Behavioral: Resistance training
Registration Number
NCT04637178
Lead Sponsor
Inland Norway University of Applied Sciences
Brief Summary

The overall objective of the study is to identify molecular determinants of the efficacy of resistance training for improving endruance performance in elite cyclists

Detailed Description

For elite endurance athletes, the addition of resistance training to habitual endurance training routines generally leads to improved endurance performance. However, this is not always the case, with several individuals failing to respond in the expected manner. This inter-individual variation is likely associated with inherent cellular and molecular charateristics of skeletal muscle. Indeed, responses to resistance training seem to be associated with muscle biological characteristics such as muscle fiber composition and ribosomal content (during the early phase of resistance training).

The study will investigate the association between muscle fibre composition (type I vs type II muscle fiber proportions) / ribosomal content in m. vastus lateralis and the effects of 10 weeks of resistance training on endurance performance in 52 elite cyclists. Half the participants will perform resistance training in addition to their habitual endurance training routines, the other half will perform endurance training-only. Muscle biopsies will be sampled from m. vastus lateralis before and after the first two weeks of the intervention. For muscle fiber composition, the hypothesis is that larger proportions of type II fibers will be associated with more pronounced benefits of resistance training. For ribosomal content, the hypothesis is that higher rRNA content at baseline and larger increases in rRNA content during the initial part of the intervention will be associated with more pronounced benefits of resistance training. No changes are expected in the non-resistance training control group.

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
25
Inclusion Criteria

Not provided

Exclusion Criteria

Not provided

Study & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Arm && Interventions
GroupInterventionDescription
Endurance trainingEndurance training (habitual)Participants (elite cyclists) will conduct habitual endurance training-only for ten weeks
Resistance training added to endurance trainingEndurance training (habitual)Participants (elite cyclists) will conduct heavy-load resistance training twice a week in addition to their habitual endurance training for ten weeks
Resistance training added to endurance trainingResistance trainingParticipants (elite cyclists) will conduct heavy-load resistance training twice a week in addition to their habitual endurance training for ten weeks
Primary Outcome Measures
NameTimeMethod
Performance during a 15-minute all-out cycling testChanges from before the intervention to immediately after the intervention

Mean power output measured during a 15-minute all-out cycling test

Performance during a 40-minute all-out cycling testChanges from before the intervention to immediately after the intervention

Mean power output measured during a 40-minute all-out cycling test

Secondary Outcome Measures
NameTimeMethod
Total RNA in muscle tissue (changes after two weeks)Changes from before the intervention to immediately after the initial two weeks of resistance training

Total RNA content in m. vastus lateralis (ug per mg tissue)

Myonuclear number (changes after two weeks)Changes from before the intervention to immediately after the initial two weeks of resistance training

Myonuclei per muscle fiber in m. vastus lateralis measured using immunohistochemistry

Muscle fiber proportions (before intervention)Before the intervention

Muscle fiber proportions in m. vastus lateralis measured using immunohistochemistry

Muscle fiber proportions (changes after two weeks)Changes from before the intervention to immediately after the initial two weeks of resistance training

Muscle fiber proportions in m. vastus lateralis measured using immunohistochemistry

Muscle fiber cross-sectional area (before intervention)Before the intervention

Cross-sectional area of muscle fibres in m. vastus lateralis measured using immunohistochemistry

Myonuclear number (before intervention)Before the intervention

Myonuclei per muscle fiber in m. vastus lateralis measured using immunohistochemistry

rRNA expression (before intervention)Before the intervention

rRNA abundances in m. vastus lateralis measured using qPCR

Total RNA in muscle tissue (before intervention)Before the intervention

Total RNA content in m. vastus lateralis (ug per mg tissue)

Muscle fiber cross-sectional area (changes after two weeks)Changes from before the intervention to immediately after the initial two weeks of resistance training

Cross-sectional area of muscle fibres in m. vastus lateralis measured using immunohistochemistry

mRNA expression (before intervention)Before the intervention

mRNA abundances in m. vastus lateralis measured using qPCR

Sprint performanceChanges from before the intervention to immediately after the intervention

Mean power output measured during a 10-second all-out cycling sprint

Fractional utilization of VO2max (incremental test)Changes from before the intervention to immediately after the intervention

Fractional utilization of VO2max measured at 4 mmol blood lactate concentrations measured during an incremental cycling exercise test (with 5 minute steps)

Fractional utilization of VO2max (15-minute performance test)Changes from before the intervention to immediately after the intervention

Fractional utilization of VO2max measured during a 15-minute performance test

Blood volumeChanges from before the intervention to immediately after the intervention

Blood volume measured using CO rebreathing

Gross efficiencyChanges from before the intervention to immediately after the intervention

Contribution of total energy turnover to power output in the fresh and fatigued state

HematocritChanges from before the intervention to immediately after the intervention

Hematocrit measured using centrifugation

Maximal oxygen consumptionChanges from before the intervention to immediately after the intervention

Maximal oxygen consumption measured during an incremental cycling exercise test to exhaustion

Maximal aerobic power outputChanges from before the intervention to immediately after the intervention

Maximal aerobic power output measured as mean power output during the last minute of an incremental cycling exercise test to exhaustion

Hemoglobin massChanges from before the intervention to immediately after the intervention

Hemoglobin mass measured using CO rebreathing (g)

Red blood cell volumeChanges from before the intervention to immediately after the intervention

Red blood cell volume measured using CO rebreathing

rRNA expression (changes after two weeks)Changes from before the intervention to immediately after the initial two weeks of resistance training

rRNA abundances in m. vastus lateralis measured using qPCR

Maximal concentric force productionChanges from before the intervention to immediately after the intervention

Maximal concentric force production measured using a seated leg press test

mRNA expression (changes after two weeks)Changes from before the intervention to immediately after the initial two weeks of resistance training

mRNA abundances in m. vastus lateralis measured using qPCR

Power output at lactate thresholdChanges from before the intervention to immediately after the intervention

Power output at 4 mmol blood lactate concentration measured during an incremental cycling exercise test (with 5 minute steps)

Plasma volumeChanges from before the intervention to immediately after the intervention

Plasma volume measured using CO rebreathing

Trial Locations

Locations (1)

Inland Norway University of Applied Sciences

🇳🇴

Lillehammer, Inland Norway, Norway

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