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Trial registered on ANZCTR

Registration number

ACTRN12623001215617p

Ethics application status

Not yet submitted

Date submitted

7/10/2023

Date registered

27/11/2023

Date last updated

27/11/2023

Date data sharing statement initially provided

27/11/2023

Type of registration

Prospectively registered

Titles & IDs

Public title

Effect of Loading on Breathing Behaviour, Muscle Activation, and Performance During Unstable versus Stable Load Resistance Training

Scientific title

Effect of Loading on Breathing Behaviour, Muscle Activation, and Performance During Unstable versus Stable Load Resistance Training in healthy males and females

Secondary ID [1]

None

Universal Trial Number (UTN)

Trial acronym

Linked study record

Health condition

Health condition(s) or problem(s) studied:

respiratory function

physical function

Condition category

Condition code

Respiratory

Normal development and function of the respiratory system

Musculoskeletal

Normal musculoskeletal and cartilage development and function

Intervention/exposure

Study type

Interventional

Description of intervention(s) / exposure

The current study will involve one initial testing session and one experimental session. All sessions will be conducted in an exercise clinic at the University of Sydney Camperdown campus (Susan Wakil Health Building). All sessions will be supervised by a strength and conditioning specialist or exercise scientist with one-on-one supervision provided to participants. The interval between the two sessions will be at least 72 hours to avoid the influence of fatigue. A session attendance checklist will be used to monitor adherence to the sessions.

The initial testing session (120 minutes) will encompass in-person screening, anthropometry, blood pressure, spirometry profile, static balance, dynamic balance, core endurance test, core strength test, and the 1RM parallel back squat.

The experimental session (150 minutes) will involve unstable load training (ULT) and traditional training (TRAD) in parallel back squats. The ULT will be the interventional condition, and the TRAD will be the control condition. A recovery period of approximately 30 minutes will be allowed between conditions to minimise the influence of fatigue.

The ULT (interventional condition) will involve a bout of parallel back squats at various loads in ascending order (40% 1RM, 50% 1RM, 60% 1RM, 70% 1RM, 80% 1RM, 90% 1RM) with unstable loads. The unstable load will be achieved by suspending weight plates on both ends of the barbell using elastic bands (Rogue Fitness, Columbus, OH, USA). The bands will be “quadruple looped” through the hole in the centre of each weight plate and hanging on the barbell. Two repetitions at each percentage of 1RM will be performed with a 60-second rest interval between attempts up to 60% 1RM and 120 seconds for 70-90%. The repetition speed of the squats will involve a 3-second eccentric phase followed by maximum velocity/effort in the concentric phase. A 20-kilogram standard Olympic barbell will be utilised for male participants, whilst a 15-kilogram standard Olympic barbell will be utilised for female participants.

Intervention code [1]

Treatment: Other

Comparator / control treatment

The TRAD (control condition) will involve a bout of parallel back squats at various loads in ascending order (40% 1RM, 50% 1RM, 60% 1RM, 70% 1RM, 80% 1RM, 90% 1RM) with stable loads. The stable load will be achieved by placing the plates on both ends of the barbell normally. Two repetitions at each percentage of 1RM will be performed with a 60-second rest interval between attempts up to 60% 1RM and 120 seconds for 70-90%. The repetition speed of the squats will involve a 3-second eccentric phase followed by maximum velocity/effort in the concentric phase. A 20-kilogram standard Olympic barbell will be utilised for male participants, whilst a 15-kilogram standard Olympic barbell will be utilised for female participants.

Control group

Active

Outcomes

Primary outcome [1]

Breath behaviour, including inspiratory volume (Vin), expiratory volume (Vex), inspiratory volume / tidal volume (Vin/Vt), expiratory volume / tidal volume (Vex/Vt), rate of breaths, breath-holding occurrence, and breath-holding duration of each squat, will be collected throughout resistance exercise. All components will be assessed together as a composite outcome.

Timepoint [1]