Researchers have found that making up for lost sleep over the weekend due to sleep deprivation during the week does not return heart rate and blood pressure levels to normal, according to a new study.

Researchers from Pennsylvania State University shared the findings in a study published in the journal Psychosomatic Medicine on Tuesday.

The researchers state that when sleep is restricted to five hours per night during the week, it leads to a deterioration in cardiovascular health, including heart rate and blood pressure.

A Pennsylvania assistant professor of biobehavioral health said in a press release on Tuesday that "only 65 percent of adults in the United States regularly get the recommended seven hours of sleep each night, and there is a lot of evidence indicating that this lack of sleep is linked to long-term cardiovascular diseases."

The researchers studied the sleep habits of 15 healthy men ages 20 to 35 over 11 days. During the first three nights, participants were allowed to sleep for up to 10 hours each night to achieve a baseline sleep level.

In the next five nights, participants were restricted to five hours of sleep per night followed by two recovery nights where they were again allowed to sleep for up to 10 hours each night.

To measure the impact of sleep recovery on cardiovascular health, the researchers monitored participants' resting heart rates and blood pressure every two hours throughout the day.

According to the study, participants’ heart rates increased by nearly one beat per minute (BPM) with each consecutive day of the study, with an average baseline heart rate of 69 beats per minute, while the average heart rate on the second recovery day was around 78 beats per minute.

Researchers noted that systolic blood pressure increased by about 0.5 mmHg each day, with an average baseline systolic blood pressure of 116 mmHg and about 119.5 mmHg by the end of the recovery period.

The researchers measured heart rate and blood pressure in participants several times during the study and also considered how the time of day could affect cardiovascular health; according to the study, heart rates are typically lower when waking up than later in the day, and measuring it consecutively could explain this difference.

Lead author David Reichmuth said, "Heart rate and systolic blood pressure increased with each consecutive day and did not return to baseline levels by the end of the recovery period."

Reichmuth added, "So despite having an additional opportunity to rest, by the end of the weekend of the study, cardiovascular systems did not recover."

Chang states that longer recovery periods from sleep may be needed to recover from several consecutive nights of sleep deprivation.

Chang said, "Sleep is a biological process, but it is also a behavioral process, and we often control it too much, emphasizing that sleep affects not only our cardiovascular health but also our weight, mental health, ability to concentrate, and our ability to maintain healthy relationships with others, among many other things."