The Perceived Point of Muscular Discomfort vs the Point of Failure in the Ageing Population- a Pilot Study

Before participation, the participant will undergo a health screening that follows the standard operating procedures of the Human Performance Laboratory. This involves measurements of height, weight, body fat percentage, blood glucose, blood pressure and heart rhythm abnormalities. Blood glucose will be measured using capillary blood via a finger prick test administered by the principal investigator. A very small amount of blood will be drawn into a capillary tube and then analysed in a machine (Biosen) to quantify the levels of blood glucose/sugar in the sample. Heart abnormalities will be measured using a device that is non-invasive and just requires the participant to place their fingers on a pad for one minute. The body fat percentage te69st is also non-invasive, requiring the participants to stand on a scale (Tanita body scanner) with their shoes and socks off.

EMG electrodes will then be placed on the triceps and quadriceps after standard skin preparation has taken place. After this the participant will complete a standardised isometric maximal voluntary contraction so the EMG activity can be standardised as % maximal voluntary contraction (%MVC). The details of the MVC protocol can be found in Appendix 2.

First the participant will be led through a standardized warm up that includes the use of elastic band exercises and joint mobility work for five minutes as seen in Appendix 3.

The participant will be shown the technique of three variations of the two exercises using a mobile phone app video; beginner, intermediate and advanced variations. They will then be asked to choose which version of the exercise they think can achieve 8-15 repetitions with.

All participants will then start with the beginner variation of the squat pattern exercise. If they are able to perform each exercise for more than 20 repetitions to technical failure they will be asked to perform the intermediate variation intermediate. If they are able to perform more than 20 repetitions to technical failure they will be asked to perform the advanced version.

This process will then be repeated for the push-up pattern, of which there are also three variations, beginner, intermediate and advanced. To minimise fatigue between sets in those that are able to perform the intermediate or advanced exercises, lower and upper body exercises will be alternated and separated by 5 minutes of rest.

Before each set they will be instructed to say the word "now" during the set when they begin to feel moderate muscle discomfort, (a 5 on a scale of 1-10), see appendix 3. (Fisher et al., 2017). and the scale is described to the participant as follows: "The scale begins at 0, which is described as no perceived discomfort. This can be likened to a perception of discomfort at a time where participant felt no noticeable sensations relating to physical activity. The scale ends at 10, which is described as the maximum perceivable discomfort. This can be likened to a perception of discomfort where the participant could not imagine the sensations relating to physical activity being any more intense."

They will then be instructed to continue this set until they can no longer complete a repetition with the correct demonstrated form (technical failure). For each of the exercises the number of repetitions between the point of muscular discomfort and failure will be calculated and correlated with %MVC.

Inclusion criteria

• Aged 60-80 years of age.
• Physically capable of resistance training.
• Able to walk unassisted.

Exclusion criteria

• Major cardiovascular (e.g. myocardial infarction, angioplasty within the last year, coronary artery bypass graft), neurological (e.g. Parkinson's disease, Alzheimer's, major anxiety or depressive disorders), muscular (e.g., muscular dystrophies, myopathies, myositis) or uncontrolled metabolic conditions (e.g. Type 1 or 2 diabetes).
• Severe obesity (BMI >39).
• Have undertaken regular resistance exercise in the last 12 months.
• Any upper or lower body musculoskeletal injury that impairs the participants ability to perform a repetition as fast as possible.
• Acute or terminal illnesses (e.g. severe locals or systemic infections, cancer).
• Current residence being within a setting of care.
• Experience of muscle pain from taking statins.