There is always a lot of confusion when it comes to stretching. The current thoughts seem to be:
- Static stretching is OK again
- Ballistic stretching is not OK
- Never stretch before exercise, it will make you weaker
- Do stretch after exercise, when you are warm.
Many runners go as far as to suggest little to no stretching, worrying that too much flexibility will both reduce their running efficiency and increase their risk of injury (a tight tendon can act as a spring as well as supporting the joint).
Personally I have been able to fix many issues with discomfort in my wrists and arms using stretching, and I find I recover more quickly after running if I stretch each evening.
Duration and frequency
Since stretching every day can be a tricky habit to stick with, it makes sense to try and optimise it by not stretching for longer than is useful.
Suggestions on how long to hold a stretch very from “around 10 seconds” all the way up to “at least 5 minutes”. Sometimes the suggestion is a vague “from 10 to 30 seconds”, and often it is suggested that multiple repetions be performed such as “15 seconds 3 to 4 times”. The rough concensus seems to be that holding for 30 seconds is optimal. It appears that this number comes from a number of studies on static stretching of the hamstrings.
In one study looking at static stretching of the hamstrings, it was found that the increase in flexibility after 6 weeks of stretching 5 days a week was larger when holding each stretch for 30 seconds than for 15 seconds. No improvement was seen when increasing to 60 seconds: 1
Three groups stretched 5 days per week for 15, 30, and 60 seconds, respectively. The fourth group, which served as a control group, did not stretch. […] no significant difference existed between stretching for 30 seconds and for 1 minute, indicating that 30 seconds of stretching the hamstring muscles was as effective as the longer duration of 1 minute.
Another study by the same authors also looked at stretch frequency 2
Subjects assigned to group 1 (12 men, 6 women; mean age=24.44 years, SD=3.35, range=21-31) did three 1-minute static stretches (10 seconds between stretches) of the hamstring muscles. Group 2 (12 men, 7 women; mean age=27.32 years, SD=5.60, range= 21-31) did three 30-second static stretches, with a 10-second rest between stretches. Group 3 (12 men, 6 women; mean age=27.33 years, SD=7.60, range=21-39) did one static stretch for 1 minute. Group 4 (12 men, 6 women; mean age = 24.78 years, SD=2.37, range=22-29) did one static stretch for 30 seconds. The fifth group (13 men, 7 women; mean age= 27.20 years, SD=4.79, range= 22-36) served as a control group and did no stretching activities. Subjects in groups 1 through 4 stretched 5 days a week for 6 weeks. […] No increase in flexibility occurred when the duration of stretching was increased from 30 to 60 seconds or when the frequency of stretching was increased from one to three times per day.
They did not test 3x10s of stretching to see if it would be equal to a single 30s stretch unfortunately.
Additionally, it seems that different muscles might have different optimal stretch times: 3
The purpose of this study was to determine which of three durations of a passive stretch was most effective in increasing hip abduction range of motion (ROM) in human subjects. Seventy-two men were randomly assigned into a control group and three passive stretch groups (15 seconds, 45 seconds, and 2 minutes). […] No increase in flexibility occurred when the duration of stretching was increased from 30 to 60 seconds or when the frequency of stretching was increased from one to three times per day.
And that the optimal stretch time might change with age: 4
(mean age = 84.7 years, SD = 5.6, range = 65-97 […] A 60-second stretch produced a greater rate of gains in ROM (60-second stretch = 2.4 degrees per week, 30-second stretch = 1.3 degrees per week, 15-second stretch = 0.6 degrees per week), which persisted longer than the gains in any other group (group 4 still had 5.4 degrees more ROM 4 weeks after treatment than at pretest as compared with 0.7 degrees and 0.8 degrees for groups 2 and 3, respectively).
This is probably not perfect, but my current protocol is to hold each stretch for 30 seconds, once a day.
- The Effect of Time on Static Stretch on the Flexibility of the Hamstring Muscles (Bandy WD, Irion JM) [return]
- The Effect of Time and Frequency of Static Stretching on Flexibility of the Hamstring Muscles (Bandy WD, Irion JM, Briggler M) [return]
- Effect of duration of passive stretch on hip abduction range of motion (Madding SW, Wong JG, Hallum A, Medeiros J.) [return]
- The effect of duration of stretching of the hamstring muscle group for increasing range of motion in people aged 65 years or older. (Feland JB1, Myrer JW, Schulthies SS, Fellingham GW, Measom GW.) [return]