Systolic blood pressure (SBP)

Systolic blood pressure (SBP) is the pressure on the artery walls as the heart contracts and forces blood out.^{1Schoenfeld and Snarr (eds.), NSCA’s Essentials of Personal Training, 3rd ed., p. 34.} It is the first, or top, number in a blood pressure reading.^{2International Sports Sciences Association, Strength and Conditioning, p. 94.} At rest it averages about 120 mmHg.^{3Haff and Triplett (eds.), Essentials of Strength Training and Conditioning, 4th ed., p. 133.}

SBP and heart rate measured together show how hard the heart is working.^{1Schoenfeld and Snarr (eds.), NSCA’s Essentials of Personal Training, 3rd ed., p. 34.} Multiply the two and you get the rate-pressure product.^{1Schoenfeld and Snarr (eds.), NSCA’s Essentials of Personal Training, 3rd ed., p. 34.}

With a cuff and stethoscope, SBP is the pressure at the first tapping sound as the cuff lets air out.^{4Schoenfeld and Snarr (eds.), NSCA’s Essentials of Personal Training, 3rd ed., p. 215.}

SBP rises with exercise. During aerobic exercise with large muscle groups, it climbs in step with the effort.^{5Schoenfeld and Snarr (eds.), NSCA’s Essentials of Personal Training, 3rd ed., p. 103.} ACSM puts the normal rise at about 10 mmHg for each MET of work.^{6Ozemek et al., ACSM’s Guidelines for Exercise Testing and Prescription, 12th ed., p. 300.} During maximal aerobic exercise, SBP can reach 220 to 260 mmHg.^{7Haff and Triplett (eds.), Essentials of Strength Training and Conditioning, 4th ed., p. 134.} It usually returns to the starting level, or lower, within 6 minutes of recovery.^{6Ozemek et al., ACSM’s Guidelines for Exercise Testing and Prescription, 12th ed., p. 300.}

In practice

• The rise is larger in men on average, and it grows with age. Some heart and blood pressure medicines blunt it.^{6Ozemek et al., ACSM’s Guidelines for Exercise Testing and Prescription, 12th ed., p. 300.}
• In an exercise test, ACSM calls SBP an exaggerated response at 210 mmHg or more in men. For women the mark is 190.^{6Ozemek et al., ACSM’s Guidelines for Exercise Testing and Prescription, 12th ed., p. 300.}
• SBP above 250 mmHg is a reason to consider stopping a test.^{6Ozemek et al., ACSM’s Guidelines for Exercise Testing and Prescription, 12th ed., p. 300.}
• SBP that falls below resting is abnormal. So is a fall of more than 10 mmHg after an early rise. This is most telling alongside other signs of poor blood flow to the heart. Either drop is a reason to stop the test.^{6Ozemek et al., ACSM’s Guidelines for Exercise Testing and Prescription, 12th ed., p. 300.}
• For limits during a training session, see hypertension.