diff --git a/src/GUI/cadencegraph.cpp b/src/GUI/cadencegraph.cpp
index d64e07d1..fe589fa0 100644
--- a/src/GUI/cadencegraph.cpp
+++ b/src/GUI/cadencegraph.cpp
@@ -63,11 +63,11 @@ QList<GraphItem*> CadenceGraph::loadData(const Data &data)
 qreal CadenceGraph::avg() const
 {
 	qreal sum = 0, w = 0;
-	QList<QPointF>::const_iterator it;
 
-	for (it = _avg.begin(); it != _avg.end(); it++) {
-		sum += it->y() * it->x();
-		w += it->x();
+	for (int i = 0; i < _avg.size(); i++) {
+		const QPointF &p = _avg.at(i);
+		sum += p.y() * p.x();
+		w += p.x();
 	}
 
 	return (sum / w);
diff --git a/src/GUI/cadencegraph.h b/src/GUI/cadencegraph.h
index a50aa984..4ffa7649 100644
--- a/src/GUI/cadencegraph.h
+++ b/src/GUI/cadencegraph.h
@@ -21,7 +21,7 @@ private:
 	qreal max() const {return bounds().bottom();}
 	void setInfo();
 
-	QList<QPointF> _avg;
+	QVector<QPointF> _avg;
 
 	bool _showTracks;
 };
diff --git a/src/GUI/heartrategraph.cpp b/src/GUI/heartrategraph.cpp
index da8ec847..c7e431c9 100644
--- a/src/GUI/heartrategraph.cpp
+++ b/src/GUI/heartrategraph.cpp
@@ -63,11 +63,11 @@ QList<GraphItem*> HeartRateGraph::loadData(const Data &data)
 qreal HeartRateGraph::avg() const
 {
 	qreal sum = 0, w = 0;
-	QList<QPointF>::const_iterator it;
 
-	for (it = _avg.begin(); it != _avg.end(); it++) {
-		sum += it->y() * it->x();
-		w += it->x();
+	for (int i = 0; i < _avg.size(); i++) {
+		const QPointF &p = _avg.at(i);
+		sum += p.y() * p.x();
+		w += p.x();
 	}
 
 	return (sum / w);
diff --git a/src/GUI/heartrategraph.h b/src/GUI/heartrategraph.h
index 1c6dce9a..cf633c44 100644
--- a/src/GUI/heartrategraph.h
+++ b/src/GUI/heartrategraph.h
@@ -20,7 +20,7 @@ private:
 	qreal max() const {return bounds().bottom();}
 	void setInfo();
 
-	QList<QPointF> _avg;
+	QVector<QPointF> _avg;
 
 	bool _showTracks;
 };
diff --git a/src/GUI/powergraph.cpp b/src/GUI/powergraph.cpp
index 9af559e0..d0926a4c 100644
--- a/src/GUI/powergraph.cpp
+++ b/src/GUI/powergraph.cpp
@@ -63,11 +63,11 @@ QList<GraphItem*> PowerGraph::loadData(const Data &data)
 qreal PowerGraph::avg() const
 {
 	qreal sum = 0, w = 0;
-	QList<QPointF>::const_iterator it;
 
-	for (it = _avg.begin(); it != _avg.end(); it++) {
-		sum += it->y() * it->x();
-		w += it->x();
+	for (int i = 0; i < _avg.size(); i++) {
+		const QPointF &p = _avg.at(i);
+		sum += p.y() * p.x();
+		w += p.x();
 	}
 
 	return (sum / w);
diff --git a/src/GUI/powergraph.h b/src/GUI/powergraph.h
index ddd0a770..03165fec 100644
--- a/src/GUI/powergraph.h
+++ b/src/GUI/powergraph.h
@@ -20,7 +20,7 @@ private:
 	qreal max() const {return bounds().bottom();}
 	void setInfo();
 
-	QList<QPointF> _avg;
+	QVector<QPointF> _avg;
 
 	bool _showTracks;
 };
diff --git a/src/GUI/speedgraph.cpp b/src/GUI/speedgraph.cpp
index db4ea222..48d10fa5 100644
--- a/src/GUI/speedgraph.cpp
+++ b/src/GUI/speedgraph.cpp
@@ -74,12 +74,12 @@ QList<GraphItem*> SpeedGraph::loadData(const Data &data)
 qreal SpeedGraph::avg() const
 {
 	qreal sum = 0, w = 0;
-	QList<QPointF>::const_iterator it;
-	const QList<QPointF> &list = (_timeType == Moving) ? _mavg : _avg;
+	const QVector<QPointF> &vector = (_timeType == Moving) ? _mavg : _avg;
 
-	for (it = list.begin(); it != list.end(); it++) {
-		sum += it->y() * it->x();
-		w += it->x();
+	for (int i = 0; i < vector.size(); i++) {
+		const QPointF &p = vector.at(i);
+		sum += p.y() * p.x();
+		w += p.x();
 	}
 
 	return (sum / w);
diff --git a/src/GUI/speedgraph.h b/src/GUI/speedgraph.h
index e7e657fc..420539f4 100644
--- a/src/GUI/speedgraph.h
+++ b/src/GUI/speedgraph.h
@@ -24,8 +24,8 @@ private:
 	void setYUnits();
 	void setInfo();
 
-	QList<QPointF> _avg;
-	QList<QPointF> _mavg;
+	QVector<QPointF> _avg;
+	QVector<QPointF> _mavg;
 
 	Units _units;
 	TimeType _timeType;
diff --git a/src/GUI/temperaturegraph.cpp b/src/GUI/temperaturegraph.cpp
index eaa624e7..0f7a4573 100644
--- a/src/GUI/temperaturegraph.cpp
+++ b/src/GUI/temperaturegraph.cpp
@@ -66,11 +66,11 @@ QList<GraphItem*> TemperatureGraph::loadData(const Data &data)
 qreal TemperatureGraph::avg() const
 {
 	qreal sum = 0, w = 0;
-	QList<QPointF>::const_iterator it;
 
-	for (it = _avg.begin(); it != _avg.end(); it++) {
-		sum += it->y() * it->x();
-		w += it->x();
+	for (int i = 0; i < _avg.size(); i++) {
+		const QPointF &p = _avg.at(i);
+		sum += p.y() * p.x();
+		w += p.x();
 	}
 
 	return (sum / w);
diff --git a/src/GUI/temperaturegraph.h b/src/GUI/temperaturegraph.h
index a30e513d..1b35f4fb 100644
--- a/src/GUI/temperaturegraph.h
+++ b/src/GUI/temperaturegraph.h
@@ -23,7 +23,7 @@ private:
 	void setYUnits(Units units);
 	void setInfo();
 
-	QList<QPointF> _avg;
+	QVector<QPointF> _avg;
 
 	bool _showTracks;
 };