Frequency and Duration of Running

Their Effects on Fitness Improvement and Injuries

VO2 Max
8%	17%	19%	8%	13%	17%
Injury
22%	24%	54%	0%	12%	39%
15 min	30 min	45 min	1 x	3 x	5 x
Duration (per session)			Frequency (per week)

Subjects were untrained men, 20 to 35 years of age. Training intensity was between 85 to 90 percent of maximum heart rate. Percentages have been rounded.

When running more than 3 days per week, or more than 30 minutes per session, additional improvements in cardiovascular fitness are small, yet the rate of orthopedic injuries are disproportionately greater. Although slightly higher increases of cardiovascular fitness were observed for the 45 minutes per session and 5 days per week groups, these programs are not recommended for beginning joggers due to significantly higher rates of injury.

Group: 15 min 30 min 45 min miles/week 1.5 to 1.75 2.9 to 3.25 4.1 to 5.1 kcal/week  500 to 600 951 to 1083 1317 to 1,533

Group: 1 x 3 x 5 x per workout 2.7 to 3.5 miles in 30 minutes kcal/week 302 to 361 926 to 1189 1651 to 2038

Injury Location	Duration Study (n)	Frequency Study (n)
Anterior leg	9	7
Knee	8	3
Ankle	4	1
Lower Back	2	3
General leg soreness	0	3
Total	25	17

Pollock ML, Gettman LR, Milesis CA, et al. Effects of frequency and duration of training on attrition and incidence of injury. Med Sci Sports Exerc 1977;9:31–6.