Peak physical fitness is determined by a few factors -- some which you control and some you don't. For example, genetics play a role in muscular strength, flexibility and aerobic endurance, three main facets of physical fitness. Genetics and the physiological design of your body cannot be changed, but you do have control over factors like your attitude toward fitness, the location of your workouts and the people who support your goals.
Your parents gave you life and are also responsible for the size and shape of your body. These genetic factors cannot be changed and have an effect on your muscular strength, flexibility and endurance. The proportion of your muscle fiber types -- whether you have more slow- or fast-twitch fibers -- determines which aspects of fitness are your strengths. For example, if you have more slow-twitch muscle fibers, you likely have greater endurance than someone who has more fast-twitch fibers. Fast-twitch fibers allow for more effective quick movement, such as sprinting.
Practice Makes Perfect
The ways in which your cardiovascular, muscular and neurological systems respond to exercise affect your physical fitness. One limiting factor is your heart rate response to a workout, which can limit your training benefits. For example, if your heart spikes too quickly during aerobic exercise there may not be an adequate amount of oxygen getting to the working muscles. That oxygen deficiency can shorten your endurance exercise session since muscles use oxygen to convert stored energy into fuel. Fitness, at this physiological level, is a factor that can be trained and improved. However, your physical fitness is specific to each exercise, so your training mode affects your results. For example, strength-training doesn't improve your running endurance, while running doesn't enhance upper body muscular strength. For overall fitness, perform a well-rounded workout routine with cardiovascular and strength exercises, along with a regular stretching routine.
Sometimes, it is your psychological and emotional response that limits your physical fitness. One of the most common reasons for not participating in exercise is a lack of time, according to Georgia State University. Lack of energy, money and support are a few other noted reasons. To offset these barriers, schedule exercise into your day and eat a healthy, well-balanced meal to increase your energy level. Many exercises such as walking and calisthenics can be done anywhere and with minimal cost. "Sports Medicine" reports that support for exercise by family, friends and peers can lead to improvements in physical fitness.
Baby, It's Cold Outside
One major factor affecting your physical fitness is the environment in which you live. If you are accustomed to exercising at sea level and switch to high-altitude training, your workout may be limited due to the decrease in oxygen pressure and your fitness will be affected. Exercising outdoors in high humidity or high heat where you are at an increased risk for dehydration or heat-related illnesses will also affect your fitness level by stopping or shortening your workouts. Other environmental factors such as rain, snow and wind may negatively affect your exercise routine, so it is best to have an alternate, indoor training plan if you mainly train outside.