diff --git a/src/PfPvPlot.cpp b/src/PfPvPlot.cpp
index dbde9994b..b16848a72 100644
--- a/src/PfPvPlot.cpp
+++ b/src/PfPvPlot.cpp
@@ -169,6 +169,9 @@ PfPvPlot::PfPvPlot(MainWindow *mainWindow)
  
     cl_ = settings->value(GC_CRANKLENGTH).toDouble() / 1000.0;
 
+    merge_intervals = false;
+    frame_intervals = true;
+
     recalc();
 }
 
@@ -415,6 +418,8 @@ PfPvPlot::showIntervals(RideItem *_rideItem)
        int num_intervals=intervalCount();
 
        if (mergeIntervals()) num_intervals = 1;
+	   if (frameIntervals() || num_intervals==0) curve->setVisible(true);
+	   if (frameIntervals()==false && num_intervals) curve->setVisible(false);
        QVector<std::set<std::pair<double, double> > > dataSetInterval(num_intervals);
 
        long tot_cad = 0;
@@ -620,3 +625,10 @@ PfPvPlot::setMergeIntervals(bool value)
     merge_intervals = value;
     showIntervals(rideItem);
 }
+
+void
+PfPvPlot::setFrameIntervals(bool value)
+{
+    frame_intervals = value;
+    showIntervals(rideItem);
+}
diff --git a/src/PfPvPlot.h b/src/PfPvPlot.h
index 0a85976d4..5d7d3fe10 100644
--- a/src/PfPvPlot.h
+++ b/src/PfPvPlot.h
@@ -57,6 +57,8 @@ class PfPvPlot : public QwtPlot
 
         bool mergeIntervals() const { return merge_intervals; }
         void setMergeIntervals(bool value);
+        bool frameIntervals() const { return frame_intervals; }
+        void setFrameIntervals(bool value);
 
     public slots:
 signals:
@@ -83,7 +85,7 @@ signals:
 	int cad_;
 	double cl_;
 	bool shade_zones;    // whether to shade zones, added 27Apr2009 djconnel
-	bool merge_intervals;
+	bool merge_intervals, frame_intervals;
 };
 
 #endif // _GC_QaPlot_h
diff --git a/src/PfPvWindow.cpp b/src/PfPvWindow.cpp
index be369f14c..7c7e06d4c 100644
--- a/src/PfPvWindow.cpp
+++ b/src/PfPvWindow.cpp
@@ -43,6 +43,9 @@ PfPvWindow::PfPvWindow(MainWindow *mainWindow) :
     mergeIntervalPfPvCheckBox = new QCheckBox;
     mergeIntervalPfPvCheckBox->setText(tr("Merge intervals"));
     mergeIntervalPfPvCheckBox->setCheckState(Qt::Unchecked);
+    frameIntervalPfPvCheckBox = new QCheckBox;
+    frameIntervalPfPvCheckBox->setText(tr("Frame intervals"));
+    frameIntervalPfPvCheckBox->setCheckState(Qt::Checked);
 
     qaLayout->addWidget(qaCPLabel);
     qaLayout->addWidget(qaCPValue);
@@ -52,6 +55,7 @@ PfPvWindow::PfPvWindow(MainWindow *mainWindow) :
     qaLayout->addWidget(qaClValue);
     qaLayout->addWidget(shadeZonesPfPvCheckBox);
     qaLayout->addWidget(mergeIntervalPfPvCheckBox);
+    qaLayout->addWidget(frameIntervalPfPvCheckBox);
 
     vlayout->addWidget(pfPvPlot);
     vlayout->addLayout(qaLayout);
@@ -73,6 +77,8 @@ PfPvWindow::PfPvWindow(MainWindow *mainWindow) :
             this, SLOT(setShadeZonesPfPvFromCheckBox()));
     connect(mergeIntervalPfPvCheckBox, SIGNAL(stateChanged(int)),
                 this, SLOT(setMergeIntervalsPfPvFromCheckBox()));
+    connect(frameIntervalPfPvCheckBox, SIGNAL(stateChanged(int)),
+                this, SLOT(setFrameIntervalsPfPvFromCheckBox()));
     connect(mainWindow, SIGNAL(rideSelected()), this, SLOT(rideSelected()));
     connect(mainWindow, SIGNAL(intervalSelected()), this, SLOT(intervalSelected()));
     connect(mainWindow, SIGNAL(intervalsChanged()), this, SLOT(intervalSelected()));
@@ -123,6 +129,14 @@ PfPvWindow::setMergeIntervalsPfPvFromCheckBox()
     }
 }
 
+void
+PfPvWindow::setFrameIntervalsPfPvFromCheckBox()
+{
+    if (pfPvPlot->frameIntervals() != frameIntervalPfPvCheckBox->isChecked()) {
+        pfPvPlot->setFrameIntervals(frameIntervalPfPvCheckBox->isChecked());
+    }
+}
+
 void
 PfPvWindow::setQaCPFromLineEdit()
 {
diff --git a/src/PfPvWindow.h b/src/PfPvWindow.h
index eda2bde7c..fd91c53bd 100644
--- a/src/PfPvWindow.h
+++ b/src/PfPvWindow.h
@@ -48,6 +48,7 @@ class PfPvWindow : public QWidget
         void setQaCLFromLineEdit();
         void setShadeZonesPfPvFromCheckBox();
         void setMergeIntervalsPfPvFromCheckBox();
+        void setFrameIntervalsPfPvFromCheckBox();
 
     protected:
 
@@ -55,6 +56,7 @@ class PfPvWindow : public QWidget
         PfPvPlot *pfPvPlot;
         QCheckBox *shadeZonesPfPvCheckBox;
         QCheckBox *mergeIntervalPfPvCheckBox;
+        QCheckBox *frameIntervalPfPvCheckBox;
         QLineEdit *qaCPValue;
         QLineEdit *qaCadValue;
         QLineEdit *qaClValue;