I am looking for research on the link between ground contact time and flight time.
I coach an older teenage athlete whose ground contact time has reduced considerably over the last 12 months and whose flight time has increased. Overall there has been only a small change in their stride length time.
Over the 12 months they have grown a little more and have become stronger.
While it is early in the season their 100m times have improved.
Is this normal. Would this improvement be down to the changes.
Yes, your athlete’s improvement is do to the change in his GCT by way of his improved leg strength.
GCT is determined by the amount of force applied to the ground by way of leg strength. The greater the force to the ground, the shorter the GCT, which increases the stride rate and stride length (time in the air).
Therefore, if you want your athlete to continue to improve his speed you must increase his leg strength while trying the avoid increasing his body mass, which will help him to deal with the pull of gravity as well.
Last night I looked at his number of strides over 2 100m races a year apart. LAst year he took about 49.5 strides and this year he is taking a little more. Is this normal considering his increased leg strength.
In increasing his strength we have been very conscious not to increase his body mass.
Actually, if your athlete is taking more strides in the 100m this year than last year, I doubt that his leg strength has improved in relationship to his body weight. However, if there has been an adjustment in your athlete’s start this year which might cause him to use shorter strides coming out of the blocks and over the first 15 to 20 meters of his race, this might be why he’s using more strides in the 100m this year than last year. On the other hand, if you’ve asked him to work on lengthening his stride while running, he might be having the opposite result, because making a conscious effort to lengthen his stride is unnatrual. His stride lengthen should be the natrual outcome of the amount of force he applies to the ground each step of the way in a race, which depends on his leg strength in relationship to his body mass/weight.
I’d like to know what exercises you’re using to help increase his leg strength?
Here is the work we’ve done over the last few months. The athlete is 16 years and had done no specific weights except irregularly mucking around with some mates. So we started doing the following exercises twice a week after training. Given his lack of weight work except for Charlie’s med ball routines we’ve taken things very slowly. Like you the more we look at it I am also confused as to why he is taking more strides than last season.
Leg Exercises
1st phase – June to mid August
Sets of 10 – muscular endurance/general strength base
We did a phase of sets of 10 when we first started off. We were doing very general, whole body exercises here like bench press and lunges, lighter weights
2nd phase – 16th August till Early October
(This was the time of our State High School competition)
3 x Sets of 8 – general strength/hypertropy (slight)
Tuesday: DEADLIFTS, PUSH PRESS and LUNGE TWISTS
Thursday: 1-LEG SQUATS, HAMSTRING CURLS and STEP-UP’S
3rd Phase – 7th October to 28th October
(We are now heading towards our National High School Champs at start of December)
4 sets of 6 – strength/base power
Tuesday: DEADLIFTS, PUSH PRESS and LUNGE TWISTS
Thursday: 1-LEG SQUATS with weight, HAMSTRING CURLS & STEP-UP’S with weight
4th and Current Phase – 28th October on
4/5 sets of 5 – explosive power
Might seem like less but have targeted the best exercises to do
Tuesday: SQUAT JUMPS with weight (5kg dumbbell each hand), SPRINT JUMPS (1 leg jumps up to a bench/box, starting in a sprint-like position) + cycling 15sec moderate, 15sec hard resistance, 15 sec no resistance x 2 (done at start like a warmup)
Thursday: PUSH PRESS & DEPTH JUMPS
4th Phase – it might seem like he is doing less but I have tried to keep each session to: 2 important leg exercises, 2 important upper body exercises, one overspeed exercise as warm-up, core routine, whole body static stretch and stretches.