Jamie wants to improve her abdominal strength. which change to her workout will her to achieve this? use a higher resistance or weight and fewer repetitions, eight to 10 repetitions per set. use lower resistance or weight and a high number of repetitions, 12 to 18 repetitions per set. use a lower resistance or weight and decrease the number of repetitions by two or three. use a higher resistance or weight and increased repetitions, at least 20 per set.