The world’s only “athletic illness” remains poorly understood.

Written by: Matt Fitzgerald

Overtraining, or overtraining syndrome (OTS), is generally characterized as an unexpected decline in performance that is not caused by an organic factor such as anemia. because the exact causes of OTS are unknown, some experts prefer the term unexplained underperformance syndrome.

The universal symptoms of OTS are performance decline and persistent fatigue. these are present in every case. There is a long list of other symptoms that are present in many but not all cases. these include depression, irritability, loss of motivation, insomnia, and changes in resting heart rate. because there is no single symptom that can be used to make a definitive diagnosis of OTS, it is notoriously difficult to diagnose.

The primary cause of OTS is excessive training over a long period of time combined with inadequate rest. however, this does not appear to be the sole cause, which is another reason some experts prefer the term unexplained underperformance syndrome. The various symptoms of overtraining are understood to represent a maladaptation to the stress of training. because all sources of stress, whether physiologic or psychological, are processed by the body in similar ways, sources of stress outside of training (e.g. job stress) can combine with training to create a total “allostatic load” that results in overtraining symptoms.

Overtraining vs. Overreaching

Experts distinguish functional overreaching from nonfunctional overreaching and overtraining. Functional overreaching is an essentially asymptomatic state where an athlete is exposed to a training load that would result in fatigue and performance decline if maintained too long. Overreaching is widely considered necessary to the attainment of peak fitness. If not carefully managed, however, functional overreaching can become nonfunctional overreaching, which is a state of fatigue and stagnating performance that is quickly reversed with rest.

Overtraining is a state of severe fatigue and performance decline that is not quickly reversed with rest. OTS is seen almost exclusively in elite athletes, as only these athletes are capable of sustaining excessive training loads long enough to develop the syndrome. Amateur athletes are far more likely to get injured or experience burnout before they ever get beyond the nonfunctional overreaching stage.

What does this mean, exactly? it means that the hormonal and neurological changes that occur in overtrained athletes do not directly impair their ability to perform. Instead, they perform poorly either because these changes make exercise feel more difficult (overtrained athletes always report increased perceived exertion at familiar exercise intensities) or because of a loss of motivation (overtrained athletes almost always report reduced motivation to exercise) or both.

Overtraining is very easy to prevent in theory, because its onset is typically gradual. Athletes in heavy training need only monitor their performance, fatigue level, and mood consistently and take measures that include but are not necessarily limited to “relative rest” (i.e. cutting back on training without stopping cold) when warning signs appear. because competitive athletes are often resistant to making unplanned reductions to their training workload, however, preventing it can be more difficult in practice than it is in theory. by far the most effective treatment for OTS is prolonged rest.

About the Author: Matt Fitzgerald is a senior editor at Competitor Group, with regular contributions to competitor.com, Triathlete, Inside Triathlon and Competitor. Matt has written 17 books, and counting, including Brain Training For Runners and Racing Weight.

Hatfield, England (ots/PRNewswire) – Zebinix(R) (eslicarbazepine acetate), an add-on (adjunctive) therapy for adults with partial-onset seizures, with or without secondary generalisation (where the seizure spreads to both sides of the brain), has been launched today in Spain by Eisai and BIAL in a co-promotion.

In 2009, the European Commission approved Zebinix based on data showing that it reduces seizure frequency and improves health-related quality of life.[1]

Epilepsy is one of the most common neurological diseases, affecting up to 400,000 people in Spain[2] – and the successful treatment of partial-onset seizures (the most common type of epilepsy) remains a challenge. up to 40% of patients with partial seizures do not achieve seizure control with current treatments.[3]

“There are many patients with epilepsy whose condition is difficult to treat with existing anti-epileptic drugs. Zebinix, developed by BIAL, is the outcome of its longstanding scientific commitment to CNS research and development, and its launch in Spain now offers a new therapeutic option which is shown to decrease seizure frequency and improve quality of life in those patients with poor seizure control,” commented mark Duffy, Business Development Director, BIAL

“Eisai’s mission to regard patients and their families as the most important participants in the healthcare process is demonstrated by our continued commitment to epilepsy in Europe. by increasing our European footprint, we are able to bring valuable treatment options to more patients with epilepsy. the launch of Zebinix in Spain is a clear example of our dedication to this therapeutic area,” commented Dr. Bettina Bauer, Head of EU Epilepsy Business Unit, Eisai Europe ltd.

In its first year Zebinix has had over 9,000 months of patient exposure.[4] Zebinix is already available in Germany, Austria, United Kingdom, Denmark, Norway, Iceland, Sweden, Portugal* Albania*, Cyprus*, Malta* and Spain (co promotion with BIAL from launch).

*Exclusively by BIAL

Zebinix(R) is the EU trade name for eslicarbazepine acetate.

Zebinix(R) is under license from Bial.

About epilepsy, partial-onset seizures and their treatment

Epilepsy is a chronic neurological disease characterised by abnormal discharges of neuronal activity causing seizures. Clinically, these manifest as convulsions or jerking of muscles. Depending on the seizure type, seizures may be limited to one part of the body, or may be generalised to involve the whole body. Patients may also experience abnormal sensations, altered behaviour or altered consciousness. Epilepsy is a disorder with many possible causes. Often the cause of epilepsy is unknown. However, anything that disturbs the normal pattern of neuron activity – from illness to brain damage to abnormal brain development, can lead to seizures.

Epilepsy is characterised by abnormal firing of impulses from nerve cells in the brain. in partial-onset seizures, these bursts of electrical activity are initially focused in specific areas of the brain, but may become more generalised; the symptoms vary according to the affected areas. Nerve impulses are triggered via voltage-gated sodium channels in the nerve cell membrane.

Treatment of partial-onset seizures, the most common type of epilepsy, presents a constant challenge – up to 40% of patients with partial-onset seizures do not achieve seizure control with current anti-epileptic drugs.3

Furthermore, central nervous system related adverse events, such as lightheadedness (dizziness), somnolence (sleepiness), and cognitive slowing (attention and memory deficits), are highly prevalent with existing anti-epileptic agents. hence, there is a need for new anti-epileptic agents that offer effective reduction in seizure frequency combined with a favourable safety profile.

About Zebinix (eslicarbazepine acetate)

Zebinix is indicated as adjunctive therapy in adults with partial-onset seizures with or without secondary generalisation.1 Zebinix is a novel, once-daily, voltage-gated sodium channel blocker.[5],[6] It preferably targets the inactivated state of the ion channel, preventing its return to the active state, and thereby reduces repetitive neuronal firing.5,6 the efficacy of Zebinix has been demonstrated an initial proof-of-concept phase II study18 and three subsequent phase III randomised, placebo controlled studies in 1049 patients with refractory partial onset seizures.[5],[7],[8] Zebinix also significantly improved patient’s health related quality of life (HRQoL) as measured by the QOLIE-31 score during a one year open label extension of the above three studies.[9],[10],[11],[12], [13] Zebinix is given orally once-daily.

The EU approval was based on data from a phase II and three phase III clinical trials. Patients in phase III had a history of at least four partial seizures per month despite treatment with up to three concomitant anti-epileptic drugs.

During the trials, patients were randomised to various dosages of Zebinix or placebo and after a 2-week titration period, were assessed over a 12-week maintenance period, with continued follow-up over a one year open-label period.

Over the 12-week maintenance period, Zebinix 800mg and 1200mg once-daily significantly reduced seizure frequency, and was significantly more effective than placebo.[5,7,8,14] Long-term safety and maintenance of therapeutic effect was demonstrated in one-year open-label extensions of these studies.[15],[16],[17]

Tolerability[5],[7],[8],[14],[18]

In the Phase II and III clinical trials adverse events mainly occurred during the first 6 weeks of treatment and the majority of patients experienced adverse events of mild to moderate intensity. after 6 weeks of treatment, there were no observed differences in the incidence of side effects between patients treated with Zebinix and the placebo group. Treatment-emergent adverse events affecting >10% of patients in the pivotal studies were dizziness, headache and somnolence.

Quality of life and depressive symptoms[9],[10],[11],[12],[13]

The effect of Zebinix on quality of life was assessed using the Quality of Life Epilepsy Inventory-31 (QOLIE-31) scale. there was a statistically and clinically significant improvement from baseline during long-term open-label therapy, including a mean relative improvement in overall quality of life (p