Rugby sevens is a contact sport contested by two teams of seven players who compete over two 7-min halves, most frequently played in a tournament style. There is currently limited research on the match demands and physical characteristics of rugby sevens players. The overall aim of this thesis was to profile the match demands and physical characteristics of players and to determine the relationship between physical characteristics and measures of match performance. Studies one and two assessed the global match demands of international and provincial rugby sevens players and compared the match demands between forwards and backs, between tournament rounds, and between the two competition levels. Differences in running demands and match activities between international forwards and backs were trivial to moderate (ES = 0.05–0.84) while differences in running demands and match activities between Pool and Cup rounds during international tournaments were trivial (ES = 0.001–0.12), though Cup round matches showed an increase in long- duration ball-in-play sequences (proportion ratio 0.46). When comparing international and provincial players, trivial to moderate differences were found in the running demands between the completion levels, with internationals covering a greater distance at very high speed (ES = 0.30) and performing a greater frequency of sprints (ES = 0.80). There were clear differences in the frequency of all match activities between the two levels of play (ES = 0.23 – 0.64) with the exception of total tackles completed. It would seem that international rugby sevens forwards and backs experience similar match demands while international and provincial match profiles are distinguished by technical factors greater so than running demands. Study three compared the anthropometrical and physical characteristics of international and provincial rugby sevens players as well as between forwards and backs across both playing levels. Players were assessed for height, mass, body composition, speed, repeated sprint ability, lower body power, upper body strength, and maximal aerobic endurance. Clear differences (2.8 – 32%; small to very large effect sizes) were observed in all anthropometrical and physical measures between international and provincial players, with the largest differences observed in repeat sprint ability (5.7%; very large effect size), 40 m sprint time (4.4%; large effect size), 50 kg squat jump peak power (32%; large effect size), and multi stage fitness test performance (19%; large effect size). Fewer and smaller differences (0.7 – 14%; trivial to large effect sizes) were found when comparing forwards and backs, with subject height being the most discriminant characteristic with forwards being taller (3.5%; large effect size). Lower level rugby sevens players should therefore seek to improve their overall physiological profile, particularly their repeat sprint ability, to reach higher levels in rugby sevens. Position-specific physical preparation programs are likely not of importance in rugby sevens given the similar profiles of forwards and backs. In study four, the relationship between defensive and attacking performance indicators and points conceded and scored, respectively, in international rugby sevens tournaments was analysed. A total of thirteen indicators were identified, with an increase of two between-team standard deviations in tackle score corresponding with a decrease of 12.4 (90% CL ± 1.8) points per match while an increase in two between-team standard deviations in line breaks resulted in an increase of 12.2 (90% CL ± 1.4) points scored per match. The focus of study five was to examine the relationship between the performance measures assessed in study three and the performance indicators analysed in study four. Ten and 40 m sprint time had moderate to large (0.32 – 0.51) negative correlations (r) with line breaks, defenders beaten, and tackle effectiveness. Repeated sprint ability and maximal aerobic capacity were moderately related to a measure of work rate (~0.38). A decrease of two between-player standard deviations in 10 m sprint time corresponded with an increase of 74% more line breaks per match. The results of this study suggest multiple physical characteristics, in particular sprint speed, repeated sprint ability, and lower body muscular power are related to match performance in rugby sevens. In study six, the effect of two power-training programs on physical characteristics previously shown to be related to rugby sevens performance (sprint speed and lower body muscular power) was investigated. Power training with a velocity emphasis was shown to be superior to similar training with a force emphasis in improving 10 m and 40 m sprint performance. Reductions in 10 m sprint performance across both groups were strongly related to an increase in horizontal force (r = - 0.96). It was concluded that rugby sevens players seeking to improve sprint performance should perform power training with a velocity emphasis. Overall, the findings from this thesis have expanded on the current knowledge base specific to match demands, player characteristics, match performance and physical preparation in rugby sevens. Position-specific training programs are likely of little priority for rugby sevens players given the similar match demands and physical characteristics between forwards and backs. Further, players seeking to improve their match performance should aim to improve specific physical characteristics. Rugby sevens players who need to improve their sprint speed should employ power-training programs with a velocity as opposed to a force emphasis.