Effects of player number and pitch size on internal and external load in small-sided Ultimate Frisbee games

This exploratory study examined the effects of player number and pitch size on internal and external load during small-sided Ultimate Frisbee games (SSGs) in elite male athletes and explored associations between playing density, expressed as area per player, and selected load indicators. Eight elite male Ultimate Frisbee players participated in SSGs across eight different configurations involving different player numbers (2v2, 3v3, 4v4) and pitch sizes (small, medium, and large). The 2v2 large-pitch was excluded because it was considered poorly representative of typical small-sided Ultimate Frisbee practice. Internal load was assessed as percentage of individual maximum heart rate (%HRmax), while external load was quantified using GPS-derived total distance, maximum speed, high-intensity running distance, and high-intensity accelerations/decelerations. Linear mixed-effects models examined the effects of player number and pitch size. LOESS curves were used only as descriptive visualizations of potential density-load patterns. Pitch size was associated with differences in locomotor variables, with larger pitches generally eliciting greater total and high-intensity running distances. Smaller formats, particularly 2v2 and 3v3, elicited higher HR responses and greater acceleration/deceleration demands than 4v4. Descriptive density analyses suggested outcome-specific tendencies, with locomotor variables generally greater in configurations providing medium-to-large relative areas per player, whereas acceleration/deceleration responses appeared less consistently related to density alone and may depend on both available space and player number. In this small homogeneous sample of elite male Ultimate Frisbee players, player number and pitch size appeared to modulate acute internal and external load responses during SSGs. However, given the limited sample size and the sparse number of density values, these findings should be interpreted as preliminary and hypothesis-generating rather than as stable effects, definitive thresholds, or practical prescription targets.