The First-Night Effect and Sex Differences in Strength and Muscular Endurance Performance

University of Alcala32 enrolled

Overview

Introduction: The first-night effect, characterized by disturbed sleep in an unfamiliar environment, may impair next-day physical performance. However, whether this response differs between men and women remains unclear. This study investigated sex differences in the effects of sleeping in an unfamiliar environment on strength and muscular endurance in resistance-trained individuals. Methods: Thirty-two resistance-trained participants (16 women, 16 men; 23 ± 4 years) completed a randomized, counterbalanced crossover study involving two conditions: sleeping for 8 h at home or in the laboratory. The following morning, participants performed bench press and back squat strength tests across 25-90%1RM, followed by muscular endurance tests to failure at 65%1RM.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

OTHER

Masking

SINGLE

Enrollment

Conditions

Sleep

Interventions

Eligibility

Sex: ALLMin age: 18 YearsMax age: 40 YearsHealthy volunteers:

Medical Language ↔ Plain English

Inclusion Criteria: * Age between 18 and 35 years.• Body Mass Index (BMI) \< 25 kg/m². * Resistance-trained individuals (more than 2 years of structured training). * Healthy men and women without neurological, cardiometabolic, immunological, or physical conditions that prevent them from exercising. * Participants must be able to perform the tests described in the following section. Exclusion Criteria: * History of neuromuscular diseases, heart disease, or conditions that may affect liver or muscle metabolism. * Use of drugs, stimulants, or sports supplements that could interfere with the dietary supplement used in the study. * Sedentary habits (less than 150 minutes/week of moderate exercise).• Having undergone prolonged periods of physical inactivity in the 6 months prior to the study. * Engaging in strenuous exercise within 48 hours prior to the tests.• Failure to replicate the same food intake on both experimental days. * Consumption of caffeine or any other stimulant the day before the tests.

Outcomes

Primary Outcomes

Mean concentric velocity at 25%, 50%, 75%, and 90% 1RM (m/s)

Mean velocity at different %1RM (25%, 50%, 75%, 90%)

Time frame: Through study completion, an average of 3 weeks

Number of repetitions performed to task failure during the bench press and back squat exercises at 65% 1RM.

In bench press and back squat exercises

Time frame: Through study completion, an average of 3 weeks

Bar velocity displacement (mean velocity, m/s) performed in 1 set at 65%1RM until task failure

In bench press and back squat exercises

Time frame: Through study completion, an average of 3 weeks

Maximal force during handgrip and isometric mid-thigh pull tests (N)

N generated

Time frame: Through study completion, an average of 3 week

Vertical Jump test (CMJ)

cm of Height and W/kg generate during a CMJ

Time frame: Through study completion, an average of 3 week

Secondary Outcomes

Mood state (tension, depression, anger, vigor, fatigue and confusion)

Participants graded a set of 29 items related to the mood on a Likert scale from 0 (not at all) to 4 (extremely) in reply to the question;How do you feel at this moment?; to assess six scales: tension, depression, anger, vigor, fatigue and confusion.

Time frame: Through study completion, an average of 3 weeks

The First-Night Effect and Sex Differences in Strength and Muscular Endurance Performance

Overview

Conditions

Interventions

Eligibility

Locations (1)

Outcomes

Primary Outcomes

Secondary Outcomes