Guidelines For Personal Trainers Taking Blood Pressure

This week’s fitness blog covers guidelines for fitness instructors when they are taking a client’s blood pressure.

When a gym instructor first meets a client, they ask questions about their goals, lifestyle, medication, and other information that could impact their training. They also assess the client’s health and fitness by taking a blood pressure reading. Too high blood pressure can be a precursor to conditions such as coronary heart disease.

Both systolic and diastolic blood pressure will be measured, and most personal trainers nowadays will use an automated blood pressure monitor rather than the traditional aneroid sphygmometer plus stethoscope method.

Systolic blood pressure

Systolic blood pressure is the pressure against the arterial walls when the left ventricle of the heart contracts. If this is too high, the result is pressure on the heart.  As any personal trainer will know, if a muscle comes under prolonged pressure, it will fatigue and potentially fail to complete its function. For the heart muscle, this will clearly have profound implications.

Diastolic blood pressure

Diastolic blood pressure occurs when the left ventricle is refilling, so there is no driving force behind the blood, even though it is still flowing through the arteries and veins.

Preparing a client for a blood pressure reading

Before taking someone’s blood pressure, a personal trainer should ensure the client sits upright with both feet flat on the floor. The client should wear loose clothing, with tight collars loosened and watches removed.

Readings are taken pre-exercise, and the client should be relaxed. Caffeine and tobacco should be avoided, as they can elevate the heart rate, and alcohol can lower blood pressure.

Some people find having their blood pressure taken a stressful experience, which can result in an elevated reading. A good personal trainer will build rapport with their clients, talk them through the process, and make them feel at ease.

Taking the blood pressure reading

The fitness instructor will attach the cuff to the left arm for standardisation, two fingers’ width above the bend in the elbow and ideally in contact with the skin. The plastic tube will be on the outside and in line with the brachial artery.

Once the client is relaxed, the personal trainer starts the machine, and the cuff inflates. The pressure increases until the pulse is cut off at the systolic limit. The machine decreases pressure, the flow of blood continues, and the diastolic reading is taken at the point where the cuff can no longer sense the palpitation of the blood going through.

If a personal trainer is using an aneroid speedometer, they will need to listen for the blood flow to stop, loosen the cuff, and then listen for the palpitations to halt.

Analysing blood pressure readings

The process of taking a client’s blood pressure should be repeated three times to get an average reading. If any of the readings vary by more than 5mg of mercury, the personal trainer should continue until they have at least two readings within 5mg. The optimal blood pressure readings are: systolic 100-120mmHg; diastolic 60-80mmHg.

Low blood pressure

If the readings are low, the client is showing signs of low blood pressure, which can cause fainting, or it may be that they haven’t eaten recently. A personal trainer should address this question before the client begins any gym programme.

Any readings below systolic 100mmHg and diastolic 60mmHg, the fitness instructor should refer their client to a doctor and not exercise them that day.

High blood pressure

Readings at the higher end of normal – 120-140mmHg for systolic and 80-85mmHg for diastolic – are known as pre-hypertensive.

Readings of around 140-160mmHh systolic or 85-90mmHg diastolic represent stage 1 hypertension; readings of 160mmHg+ systolic or 90mmHg+ diastolic fall into stage 2 hypertension. Some gyms will refer a client to their GP at stage 1, some at stage 2.

Generally it’s considered worse to have a high diastolic than a high systolic rate. Equally, there’s a danger that if a client’s systolic rate is 160 while resting, it could quickly elevate to 180 or 200+ during exercise.

Blood pressure increases with age and the ASCM (American Sports College of Medicine) has provided a chart to show the mean systolic and diastolic rates for different ages and genders during a maximal treadmill exercise.

Age                              Men                                              Women

                       SBP                 DBP                            SBP                 DBP

18-29             182±22           69±13                         155±19           67±12

30-39             182±20           76±12                         158±20           72±12

40-49             186±22           78±12                         165±22           76±12

50-59             192±22           82±12                         175±23           78±11

60-69             195±23           83±12                         181±23           79±11

70-79             191±27           81±13                         196±23           83±11

ACSM Guidelines for Exercise Testing (2000)