Lactic acid will build up. That causes a burning sensation.
Lactic acid
Lactic acid is formed by anaerobic respiration, and builds up in the muscles.
Work a good honest day's hard physical labour.
by doing work hard like runing playing sports
No easy ones, just hard, time consuming, and boring, hard work.
Your muscles are growing to make you strong and you've been working them hard
its really hard i need help
Because your muscles are sore after a long day of hard nonstop work.
"Butt crunches" are a type of exercise designed to improve the strength and tone of the "butt" muscles. These are the gluteus muscles on the backside. If you clench the muscles as hard as you can and then relax, you've done a "butt crunch."
Specificity - Choosing a type of exercise that is related to the sport you do. Progression - Gradually progress/increase the exercise you are doing. Overload - Doing more exercise than what the muscles are used do. Reversibility - The muscles slowly decrease in strength due to a stop in exercise. Tedium - Varies of different exercising do prevent boredom. Frequency - How often you exercise. Intensity - How hard you exercise. Time - How long you exercise for. Type - The type of exercise you do.
A primary benefit of exercising with an exercise ball as opposed to exercising directly on a hard flat surface is that the body responds to the instability of the ball to remain balanced, engaging many more muscles to do so. Muscles become stronger and sturdier over time to keep balance. Most frequently, the core body muscles. The abdominal muscles and back muscles are the main focuses of using an exercise ball in fitness programs.
1. Anything that makes you sweat and breathe hard for a half hour, and 2. Any hard exercise that will strengthen muscles . . . toned-up muscles burn more calories than weak ones.