Effects of Heat-suit Training on Biological and Performance Characteristics in Elite Cyclists

Inland Norway University of Applied Sciences53 enrolled

Overview

The overall objective of the study is to investigate the effects of five weeks of heat-suit training on training-associated changes in hemoglobin mass, skeletal muscle characteristics and endurance exercise performance in elite cyclists

Endurance exercise performance depends on a range of determinants, including hemoglobin mass in blood and content of respiratory mitochondria in skeletal muscle. Low-intensity training (LIT) with heat exposure may be beneficial for development of these variables. The purpose of this study is to investigate the effects of five weeks of LIT-training with heat suit (five times a week; 50 min per session) on hemoglobin mass and other blood characteristics in elite cyclists (males and females) compared to a non-heat-suit training control group, including subsequent investigation of the retrograde effects of \~one month of training without heat suit. The study will also investigate the effects of heat-suit training on endurance exercise performance/performance determinants and other muscle biological charateristics, and will investigate the basic characteristics of mitochondrial function and abundances in these highly trained athletes. Training sessions with heat suit (or lack thereof) will complement the habitual training routines of the participants.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

NONE

Enrollment

Conditions

Heat-suit Endurance Training Non-heat-suit Endurance Training

Interventions

Heat-suit endurance trainingBEHAVIORAL

Participants (elite cyclists) will conduct five 50-minute low-intensity cycling sessions with heat suit per week for five weeks. These sessions will complement their habitual training routines, which will consist of endurance training with intensities at or below lactate threshold. Participants will ingest 100 mg Fe2+ on a daily basis to support de novo synthesis of hemoglobin

Non-heat-suit endurance trainingBEHAVIORAL

Participants (elite cyclists) will conduct low-intensity cycling without heat suit for five weeks (volume- and intensity-matched to the heat-suit arm). Participants will ingest 100 mg Fe2+ on a daily basis to support de novo synthesis of hemoglobin

Eligibility

Sex: ALLMin age: 18 YearsMax age: 45 YearsHealthy volunteers:

Medical Language ↔ Plain English

Inclusion Criteria: * VO2max \> 65 ml/kg/min (male participants) * VO2max \> 50 ml/kg/min (female participants) * \>7 hours of endurance training per week for the 6 months leading up to the study

Locations (1)

Inland Norway University of Applied Sciences

Lillehammer, Inland Norway, Norway

Outcomes

Primary Outcomes

Hemoglobin mass

Hemoglobin mass measured using CO rebreathing (g)

Time frame: Changes from before the intervention (T0) to immediately after the intervention (T1)

Secondary Outcomes

Maximal oxygen consumption

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

Time frame: Changes from before the intervention (T0) to immediately after the intervention (T1)

Maximal aerobic power output

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

Time frame: Changes from before the intervention (T0) to immediately after the intervention (T1)

Power output at lactate threshold

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

Time frame: Changes from before the intervention (T0) to immediately after the intervention (T1)

Gross efficiency

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

Time frame: Changes from before the intervention (T0) to immediately after the intervention (T1)

Fractional utilization of VO2max (incremental test)

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

Time frame: Changes from before the intervention (T0) to immediately after the intervention (T1)

Fractional utilization of VO2max (15-minute performance test)

Data from ClinicalTrials.gov

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

Time frame: Changes from before the intervention (T0) to immediately after the intervention (T1)

Sprint performance

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

Time frame: Changes from before the intervention (T0) to immediately after the intervention (T1)

Performance during a 15-minute all-out cycling test

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

Time frame: Changes from before the intervention (T0) to immediately after the intervention (T1)

Performance during a 40-minute all-out cycling test

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

Time frame: Changes from before the intervention (T0) to immediately after the intervention (T1)

Maximal concentric force production

Maximal concentric force production measured using a seated leg press test

Time frame: Changes from before the intervention (T0) to immediately after the intervention (T1)

Gene expression in skeletal muscle

RNA abundances in m. vastus lateralis measured using qPCR (e.g. messenger RNA and ribosomal RNA)

Time frame: Changes from before the intervention (T0) to immediately after the intervention (T1)

Mitochondrial respiration in skeletal muscle

The ability of muscle mitochondria (extracted from homogenate; m. vastus lateralis) to consume oxygen in vitro

Time frame: Immediately after the intervention (T1)

Mitochondrial content in skeletal muscle

Mitochondria content in m. vastus lateralis measured using electron microscopy

Time frame: Immediately after the intervention (T1)

Total RNA content in skeletal muscle

Total RNA content in m. vastus lateralis (per unit tissue weight) measured using spectrophotometry

Time frame: Changes from before the intervention (T0) to immediately after the intervention (T1)

Blood volume

Blood volume measured using CO rebreathing

Time frame: Changes from before the intervention (T0) to immediately after the intervention (T1)

Plasma volume

Plasma volume measured using CO rebreathing

Time frame: Changes from before the intervention (T0) to immediately after the intervention (T1)

Red blood cell volume

Red blood cell volume measured using CO rebreathing

Time frame: Changes from before the intervention (T0) to immediately after the intervention (T1)

Hematocrit

Hematocrit measured using centrifugation

Time frame: Changes from before the intervention (T0) to immediately after the intervention (T1)

Hemoglobin mass

Hemoglobin mass measured using CO rebreathing (g)

Time frame: Changes from immediately after the intervention (T1) to one month after the intervention (T2)

Blood volume

Blood volume measured using CO rebreathing

Time frame: Changes from immediately after the intervention (T1) to one month after the intervention (T2)

Plasma volume

Plasma volume measured using CO rebreathing

Time frame: Changes from immediately after the intervention (T1) to one month after the intervention (T2)

Red blood cell volume

Red blood cell volume measured using CO rebreathing

Time frame: Changes from immediately after the intervention (T1) to one month after the intervention (T2)

Hematocrit

Hematocrit measured using centrifugation

Time frame: Changes from immediately after the intervention (T1) to one month after the intervention (T2)