TABLE 2. COMPILATION OF PROSPECTIVE STUDIES ON POST-EXERCISE SYNCOPE.

Prospective studies in which pre-syncopal rates during head-up tilt or tolerance to lower body negative pressure were assessed during recovery from exercise.

Reference	Exercise	Environment	Incidence
1 Moderate-intensity exercise
Mayerson, 1944	10 min cycling @ 45 w	24 to 32°C	54% pre-syncopal; 60 to 75 head-up tilt [15 min]
Gratze et al., 2008	42.2 km marathon	20°C, 78% humidity	27% pre-syncopal; active standing [6 min]
Privett et al., 2010a	42.2 km marathon	10 to 11°C, light rain	10% pre-syncopal; active standing [3 min]
Murrell et al., 2009	4.5 h running @ 70–80% maximal heart rate	15°C, 72% humidity	81% pre-syncopal; 60 head-up tilt [15 min]
Eichna et al., 1947a	51.5 km hike with pack	“Moderately warm”	54% pre-syncopal; 70 head-up tilt [5 min]
Holtzhausen & Noakes, 1995	80 km ultra-marathon	14 to 25°C, 44 to 24% humidity	23% pre-syncopal; active standing [10 min]
2 High-intensity exercise
Brogdon & Hellebrandt, 1940	Brief “violent” exercise	n/a	2 out of 3 pre-syncopal; active standing
Eichna et al., 1947a	Maximal exercise for up to 5 min	23°C	58% pre-syncopal; 70 head-up tilt [5 min]
Bjurstedt et al., 1983	Graded maximal cycle test	21°C	83% pre-syncopal; 70 head-up tilt [6 min]
Privett et al., 2010b	Graded maximal treadmill test	23°C	100% pre-syncopal; active standing [10 min]
Lacewell et al., 2013	Supra-maximal exercise for 1 min [modified Wingate test]	23°C, 40% humidity	58% pre-syncopal; 60 head-up tilt [15 min]
3 Exercise in the heat
Luft et al., 1976	2 h intermittent cycling @ 30% VO2max	50°C, 15% humidity	Lower body negative pressure tolerance was reduced 31%
Shvartz et al., 1977	3 h bench stepping @ 40 w	39°C, 50% humidity	46% pre-syncopal; leaning upright against wall [20 min]
McCord et al., 2008	45 min running @ 50% VO2max	35°C, 30% humidity	53% pre-syncopal; 60 head-up tilt [15 min]
4 Exercise at altitude - No prospective studies
5 Resistance exercise - No prospective studies