## 1 Introduction  
The use of blood flow restriction (BFR) of the limbs during low-load resistance training [1, 2, 3, 4, 5] is beneficial during musculoskeletal rehabilitation following an injury or surgery when the use of the traditionally recommended higher training loads are not feasible [6, 7, 8, 9]. The results of using BFR during resistance training has also increased its use among athletes [10, 11, 12] and the fitness industry. The use of BFR during resistance training partially restricts arterial blood flow into the muscle and occludes venous blood flow [13, 14, 15, 16]. Although the restriction of arterial blood flow can be accomplished with the use of elastic wraps [17, 18, 19], the use of an inflatable cuff allows for better control of blood flow restriction. The use of a given absolute cuff pressure (e.g., 200 mmHg) for the left and right limbs or for different individuals can result in different levels of blood flow restriction between the limbs or between individuals [14, 15, 20, 21, 22, 23, 24]. Thus, the current recommendations are to use a percentage of the limb's arterial occlusion pressure (AOP) to restrict blood flow during exercise [5, 25, 26, 27]. Blood flow restriction during low-load resistance training is effective when the cuff is inflated to 40% to 80% of the limb's AOP [5, 25, 26, 27]. Thus, the accurate measurement of the limbs AOP is essential to the safe and effective use of BFR during resistance training. Studies measuring AOP have used two different protocols to inflate the occlusion cuff. One protocol increases the pressure of the occlusion cuff incrementally [28, 29, 30, 31]. This involves inflating the cuff to 50 mmHg for 30 s, then deflating the cuff for 10 s, then inflating the cuff in increments of 30 mmHg for 30 s followed by deflating the cuff for 10 s until arterial blood flow is no longer detected. The cuff is then inflated for 30 s to a pressure that is 10 mmHg less than the pressure at which arterial blood flow was no longer detected and then deflated for 10 s. This is repeated by inflating the cuff for 30 s to a pressure that is 10 mmHg less than the previous pressure, then deflated for 10 s, until arterial flow is again detected. The cuff is then slowly inflated to the point of arterial occlusion. The second protocol increases the pressure of the occlusion cuff continuously [32; 33; 34; 35; 36; 37; 38; 39; 40; 41; 42; 43; 44]. This involves inflating the cuff to 50 mmHg then gradually increasing the pressure of the cuff at a specific rate (e.g., 10 mmHg every 10 s) until arterial blood flow is no longer detected. When using either protocol, the cuff pressure at which arterial blood flow is no longer detected is recorded as the AOP. Although previous studies have used either of the two cuff inflation protocols, we are not aware of any study that has compared the AOP when using both cuff inflation protocols. Although previous studies have included male and female participants [33; 34; 35; 36; 37; 38; 39; 41; 43; 44; 38; 39; 45], only a few studies report sex differences in AOP. [PERSON] et al. [36] reported that the sex differences in AOP of the brachial artery of the right arm using three different occlusion cuff sizes (widths) were small and of no practical significance. [PERSON] et al. [40] also reported significant sex differences in AOP of 12 mmHg of the brachial artery of the right arm. [PERSON] et al. [32] recently reported large and significant sex differences in the AOP of the superficial femoral artery in both the dominant and non-dominant legs. Almost all studies have measured AOP in only one arm or one leg. Studies typically identify the limb of interest as the right or left limb and only a few studies identify the limb as the \"dominant\" arm [30] or leg [32; 45]. In studies that have reported measurements or interventions in both limbs, differences in AOP between limbs have not been reported [6; 28; 46; 47; 48; 49; 50]. Two recent studies that have reported the AOP of both limbs. [PERSON] et al.