This study will utilise the Randomised Controlled Trial (RCT) design. Following completion of the baseline measurements, participants will be randomly assigned to either the control group or the intervention group.

Control Group Control group will be asked to maintain normal activity levels for 24 weeks. On completion of the 24 weeks, 12-week University of Glasgow Sports gym membership will be given.

Intervention Group The overall aim of the intervention is for participants to participate in muscle strengthening exercises, of choice, two days a week. These exercises can include weight machine, resistance band and body weight resistance exercises, alongside strength training classes such as yoga and body pump. The intervention will begin with weekly education sessions over the first 4 weeks, to help make sure participants are confident and competent in performing exercises. Participants will be given a gym membership for the 12-week intervention period and asked to log all muscle strengthening exercises that participants participate in. Throughout the intervention, participants will receive weekly support reminder messages via WhatsApp from the research team, and researcher will also set up a social support group on WhatsApp for the participants. Weekly group-based exercise sessions with the researcher will also be offered to the participants; these will be optional.

The following data will be collected from all participants. All measures will be collected at baseline, mid-intervention measurement (week 6), post-intervention (week 12), and follow-up (week 24) except for follow-up interview and participants will be given an Amazon voucher worth £25 for every measurement period attend. Each test/measure is detailed further below.

During baseline measurement, researcher will ask the participants on their age, postcode, ethnic background, work situation, highest qualification completed, marital status, caregiver or not and the rating of health. Following this researcher will measure participants' body composition where the weight, height, fat mass, fat percentages, muscle mass and muscle size will be recorded.

Muscular strength will be measured using three strength tests which are the grip strength test, back strength test and maximal voluntary contraction. Participants will be shown how to perform the test by the research team before performing it. Participants will be asked to do each test 3 times with rest in between each attempt. The body composition and strength test will be conducted again in week 6, 12 and 24.

Intervention group will be involved in a follow-up interview during the measurement visit on week 12 and 24 to discuss the experiences and feedback on the intervention with the researchers.

Inclusion Criteria:

• female
• between 18-45 years old
• living in Glasgow area
• not currently achieving the government recommendation of 2 days a week of muscle-strengthening activities

Exclusion Criteria:

• did not pass the Physical Activity Readiness Questionnaire for Everyone (PAR-Q+)
• have blood pressure > 150/90 mmhg
• currently pregnant, planning to get pregnant within the next 6 months or in post-partum period in the past 6 months
• have intellectual disabilities

Female