Why is it important to warm up before playing sports or exercise?

Question

Why it is necessary to boost your body temperature while doing exercise why we can not start without warm up our body?

Answer 1

Scientif research on the argument is contradictory, some studies see minuscule increases in performance with warm ups while others don't see any at all. This might be attributed to placebo effect, some people suggest that warming up is nothing more than mental preparation.

Warm-up with weighted bat and adjustment of upper limb muscle activity in bat swinging under movement correction conditions.

The effects of weighted bat warm-up on adjustment of upper limb muscle activity were investigated during baseball bat swinging under dynamic conditions that require a spatial and temporal adjustment of the swinging to hit a moving target. Seven male college baseball players participated in this study. Using a batting simulator, the task was to swing the standard bat coincident with the arrival timing and position of a moving target after three warm-up swings using a standard or weighted bat. There was no significant effect of weighted bat warm-up on muscle activity before impact associated with temporal or spatial movement corrections. However, lower inhibition of the extensor carpi ulnaris muscle activity was observed in a velocity-changed condition in the weighted bat warm-up, as compared to a standard bat warm-up. It is suggested that weighted bat warm-up decreases the adjustment ability associated with inhibition of muscle activation under movement correction conditions.

Do You Need to Warm-Up Before Lifting?

There were no significant differences between the number of repetitions performed in any of the warm-up conditions nor was their a difference in the fatigue index, which is a formula that assess the decline in number of repetitions across the first and last sets of each exercise. In combination, these findings indicate that the warm-up procedures analyzed in this study had no effect on performance.

Effect of different warm-up procedures on the performance of resistance training exercises.

15 men performed 3 exercises (4 sets of bench press, squat, and arm curl at 80% of 1RM) to failure in 4 conditions (control, specific, aerobic, and combined). Outcome measures included the sum of repetitions and a fatigue index measuring the decline between sets. There was no significant difference for the sum of repetitions or for fatigue index among conditions for the 3 exercises. Performance in the resistance training exercises was not influenced by warm-up.

Cool downs seem to be more effective than warm ups. but warm ups still seem to hold some effects.

The purpose of this study was to compare the effects of a physical education-based stretching program performed during warm-up and cool-down periods on hamstring extensibility in schoolchildren aged 9- 10 years. A sample of 73 schoolchildren, 36 boys and 37 girls, aged 9-10 years old from three classes were clustered randomly assigned to a no-training group (n = 24), warm-up group (n = 25), or cooldown group (n = 24). During physical education classes, the students of the warm-up and cool-down groups performed a four-minute stretching program twice a week for ten weeks during the warm-up and the cool-down periods, respectively. Hamstring extensibility was estimated by the classic sit-and-reach test at the beginning and at the end of the stretching intervention program. The results of the ANOVA showed that both the warm-up and cool-down students had statistically significant higher values on the hamstring extensibility than the no-training students (p < 0.05). The warm-up and cool-down groups did not show statistically significant differences. Nevertheless, the cool-down students obtained a slightly higher magnitude effect when compared with the warm-up group (g = 0.67 and g = 0.56, respectively). In addition to the slight higher improvement during the cool-down, due to the negative effect of static stretching on performance as previously found in the literature, it seems that physical education teachers should improve students´ flexibility during the cool-down period of the sessions.

No scientific study has yet found any effect on injury risk reduction from warming up as far as I know.